Novel high-precision forwarding type satellite time service system and related method thereof

Abstract

The invention discloses a novel high-precision forwarding type satellite time service system and a related method thereof. Relates to the technical field of space, in the system, a self-transmitting and self-receiving end and a forwarding end are both in communication connection with a satellite; a long pseudo-range ranging signal and a long forwarding ranging signal exist among the self-transmitting and self-receiving end, the satellite and the forwarding end, and the carrier frequency of the long pseudo-range ranging signal and the carrier frequency of the long forwarding ranging signal have a preset carrier frequency relationship. The forwarding end can determine the ionosphere time delay relation of the corresponding signals in the long forwarding ranging signals and the long pseudo-range ranging signals, and determine the relative clock difference between the self-transmitting and self-receiving end and the forwarding end based on the long pseudo-range ranging value, the long forwarding ranging value and the preset carrier frequency relation. The novel high-precision forwarding type satellite time service system provided by the invention has the advantages of high time service precision, low installation condition, low satellite cost and the like.

Description

Technical Field

[0001] This application relates to the field of space technology, and in particular, to a new type of high-precision retransmission satellite time service system and related methods. Background Art

[0002] China's first-generation satellite navigation system is a satellite radio positioning system. A satellite radio positioning system (Radio Determination Satellite System) refers to a system that transmits signals from a central station. Through the radio propagation time between the satellite and the user, information such as the user's coordinates, speed, and direction can be measured, and short messages can be transmitted. It is abbreviated as the RDSS system. This system usually consists of two satellites and can realize the functions of positioning, speed measurement, communication, and time service, and is often called a dual-star positioning system.

[0003] The RDSS system provides time service to users, which is divided into two types: one-way time service and two-way time service, and the time service accuracies are approximately 100 ns and 10 ns respectively.

[0004] The China Area Position System (CAPS) is a satellite navigation system developed by the Chinese Academy of Sciences. It is a regional satellite navigation system. This system broadcasts two C-band ranging signals for satellite communication. After being retransmitted by the satellite, two C-band ranging signals are formed. Users receive and measure the two signals to achieve positioning and time service.

[0005] The common feature of the RDSS system and the CAPS system is that the atomic clock is placed in the ground operation and control center, and there is no on-board atomic clock on the satellite, only a transponder.

[0006] When the two systems provide time service to users, the ranging signal passing through the ionosphere will generate ionospheric delay error. To solve the ionospheric delay error, it is usually necessary to use an ionospheric delay model or data provided by a third party to solve it. Even if the ionospheric delay is not solved, but directly regarded as an error, the positioning and time service errors are naturally large. How to eliminate the ionospheric delay and improve the time service accuracy and positioning accuracy is a problem that needs to be solved.

[0007] In response to this problem, this application proposes a new type of system that combines the long pseudo-range ranging signal in the CAPS system, the long retransmission ranging signal in the RDSS system, and the theoretical depth of ionospheric delay, and uses the relationship between the carrier frequencies of the ranging signals to solve the ionospheric delay error problem.

[0008] The above content is only used to assist in understanding the technical solution of this application, and does not represent an admission that the above content is prior art. Summary of the Invention

[0009] To achieve the above object, the present application provides a novel high-precision transponder satellite timing system and related methods to solve the deficiencies in the prior art.

[0010] In view of the problem that the double-star positioning system has difficulty in overcoming the ionospheric delay, the present application proposes a system with at least one long pseudo-range ranging signal, at least one main transponder ranging signal and at least one slave transponder ranging signal. The present application combines the characteristics of the satellite transponder with the carrier frequency multiplexing technology and multi-access characteristics of the spread-spectrum signal, and constrains the carrier frequency of the long pseudo-range ranging signal and the carrier frequency of the long transponder ranging signal to satisfy a certain relationship, or constrains the carrier frequency of the long pseudo-range ranging signal and the carrier frequencies of the main transponder ranging signal and the slave transponder ranging signal to satisfy a certain relationship. It creatively proposes that by using the relationship between the long pseudo-range ranging value, the long transponder ranging value or the main transponder ranging value and the slave transponder ranging value and the preset carrier frequency, a novel high-precision transponder satellite timing system and related methods can be realized.

[0011] To achieve the above object, the present application provides a novel high-precision transponder satellite timing system, characterized in that the system includes a satellite, a self-transmitting and self-receiving end and a transponder end, and the self-transmitting and self-receiving end and the transponder end are both communicatively connected to the satellite; there are m long pseudo-range ranging signals between the self-transmitting and self-receiving end, the satellite and the transponder end, and there are h main transponder ranging signals between the satellite and the self-transmitting and self-receiving end, and r slave transponder ranging signals between the satellite and the transponder end; wherein, the carrier frequencies of the m long pseudo-range ranging signals, the carrier frequencies of the h main transponder ranging signals and the carrier frequencies of the r slave transponder ranging signals satisfy a first preset carrier frequency relationship, and the signals between the self-transmitting and self-receiving end and the satellite and the signals between the transponder end and the satellite each have at least two different carrier frequencies, and m, h, and r are all positive integers greater than or equal to 1;

[0012] Alternatively, there are m long pseudorange ranging signals and s long retransmitted ranging signals between the self-transmitting and self-receiving end, the satellite, and the retransmitting end. Among them, the carrier frequencies of the m long pseudorange ranging signals and the carrier frequencies of the s long retransmitted ranging signals satisfy a second preset carrier frequency relationship. Moreover, the signals between the self-transmitting and self-receiving end and the satellite, and the signals between the retransmitting end and the satellite all have at least two different carrier frequencies. Both m and s are positive integers greater than or equal to 1. Among them, the long pseudorange ranging signal consists of a pseudorange uplink signal and a pseudorange downlink signal. The pseudorange uplink signal is broadcast by the self-transmitting and self-receiving end or the retransmitting end. The satellite forwards the pseudorange uplink signal into the pseudorange downlink signal. The retransmitting end or the self-transmitting and self-receiving end receives the pseudorange downlink signal. The long retransmitted ranging signal consists of a first uplink signal broadcast by the self-transmitting and self-receiving end, a first downlink signal formed by the satellite receiving and retransmitting the first uplink signal, a second uplink signal formed by the retransmitting end receiving and retransmitting the first downlink signal, and a second downlink signal formed by the satellite receiving the second uplink signal and retransmitting it to the self-transmitting and self-receiving end. The main retransmitted ranging signal consists of a main uplink signal and a main downlink signal. The self-transmitting and self-receiving end broadcasts the main uplink signal and receives the main downlink signal. The satellite receives the main uplink signal and forwards it to form the main downlink signal. The slave retransmitted ranging signal consists of a slave uplink signal and a slave downlink signal. The retransmitting end broadcasts the slave uplink signal and receives the slave downlink signal. The satellite receives the slave uplink signal and forwards it to form the slave downlink signal.

[0013] In addition, to achieve the above object, the present application also provides an inter-station time synchronization system, including: the novel high-precision retransmitted satellite time transfer system according to any embodiment of the present application; when there are multiple self-transmitting and self-receiving ends or retransmitting ends, the multiple self-transmitting and self-receiving ends or retransmitting ends achieve time synchronization with each other through data exchange.

[0014] In addition, to achieve the above object, the present application further provides a satellite timing method, which is applied to the novel high-precision retransmission satellite timing system described in any embodiment of the present application. The method is executed by a computing device, and the method includes: obtaining m long pseudo-range ranging values, h master retransmission ranging values, and r slave retransmission ranging values based on the communication results with the self-transmitting and self-receiving end and the retransmission end, where the master retransmission ranging values are measured by the self-transmitting and self-receiving end for the master retransmission ranging signal, the slave retransmission ranging values are measured by the retransmission end for the slave retransmission ranging signal, the long pseudo-range ranging values are measured by the self-transmitting and self-receiving end or the retransmission end for the long pseudo-range ranging signal, and m, h, and r are all positive integers; respectively using long pseudo-range ranging expressions to characterize each of the long pseudo-range ranging values and using retransmission ranging expressions to characterize each of the master retransmission ranging values and each of the slave retransmission ranging values; determining the relative clock difference between the self-transmitting and self-receiving end and the retransmission end based on each of the long pseudo-range ranging values, each of the master retransmission ranging values, each of the slave retransmission ranging values, and the first preset carrier frequency relationship characterized by the corresponding expressions.

[0015] In addition, to achieve the above object, the present application further provides a satellite timing method, which is applied to the novel high-precision retransmission satellite timing system described in any embodiment of the present application. The method is executed by a computing device, and the method includes: obtaining s long retransmission ranging values and m long pseudo-range ranging values based on the communication results with the self-transmitting and self-receiving end and the retransmission end, where the long retransmission ranging values are measured by the self-transmitting and self-receiving end for the long retransmission ranging signal, the long pseudo-range ranging values are measured by the self-transmitting and self-receiving end or the retransmission end for the long pseudo-range ranging signal, and s and m are both positive integers; respectively using long pseudo-range ranging expressions to characterize the long pseudo-range ranging values and using long retransmission ranging expressions to characterize the long retransmission ranging values; determining the relative clock difference between the self-transmitting and self-receiving end and the retransmission end based on each of the long pseudo-range ranging values, each of the long retransmission ranging values, and the second preset carrier frequency relationship.

[0016] The novel high-precision retransmission satellite timing system and related methods provided by the embodiments of the present application have the following advantages:

[0017] 1. The method of the embodiment of the present application does not rely on ionospheric data provided by a third party, and completely uses its own measurement data and ionospheric delay relationships to eliminate or partially eliminate ionospheric delay, thereby improving accuracy, and at the same time, it can also improve the security and controllability of the system;

[0018] 2. Because the satellite timing method of the embodiment of the present application has low requirements for the coordinate accuracy of satellites and self-transmitting and self-receiving ends, that is, accurate satellite coordinates and self-transmitting and self-receiving end coordinates are not required to obtain the Sagnac effect, and then the satellite clock difference can be obtained;

[0019] 3. The solution of the embodiment of the present application does not require satellite-ground coarse synchronization requirements;

[0020] 4. Compared with the current RDSS satellite timing and CAPS satellite timing, the satellite timing service provided by the present application has the advantages of high accuracy and low installation conditions. Brief Description of the Drawings

[0021] Figure 1 It is a schematic structural diagram of the first new high-precision transponder satellite timing system provided by the embodiment of the present application;

[0022] Figure 2 It is a schematic structural diagram of the second new high-precision transponder satellite timing system provided by the embodiment of the present application;

[0023] Figure 3 It is a schematic structural diagram of yet another new high-precision transponder satellite timing system provided by the embodiment of the present application;

[0024] Figure 4 It is a schematic structural composition diagram of a satellite, a self-transmitting and self-receiving end, and a transponder according to an embodiment of the present application;

[0025] Figure 5 It is a schematic structural composition diagram of a satellite, a self-transmitting and self-receiving end, and a transponder according to another embodiment of the present application;

[0026] Figure 6 It is a flowchart of a satellite timing method according to an embodiment of the present application;

[0027] Figure 7 It is a flowchart of a satellite timing method according to another embodiment of the present application.

[0028] The realization of the purpose, functional features, and advantages of the present application will be further described with reference to the embodiments and the accompanying drawings. Detailed Embodiments

[0029] It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application. To solve the above-mentioned realistic and important practical problems, the embodiments of the present application provide a new high-precision transponder satellite timing system and related methods.

[0030] First, the meanings of the parameters involved in the exemplary embodiments will be uniformly described as follows:

[0031] First, the parameters in the long pseudorange ranging value expressed by formula (p1) need to be explained.

[0032] Since the long pseudorange ranging signal can be that the self-transmitting and self-receiving end transmits a pseudorange uplink signal and the transponder receives a pseudorange downlink signal; or the transponder transmits a pseudorange uplink signal and the self-transmitting and self-receiving end receives a pseudorange downlink signal.

[0033] When the self - transmitting and self - receiving end emits and the relay end receives the long pseudo - range ranging signal, the subscript of the up - link part of the long pseudo - range ranging value is represented by pu. At this time, the up - link pseudo - range signal passes through the ionosphere between the self - transmitting and self - receiving end and the satellite. The subscript of the down - link part of the long pseudo - range ranging value is represented by pd. At this time, the down - link pseudo - range signal passes through the ionosphere between the relay end and the satellite;

[0034] R true,pu,i (n), I pu,i (n), T duiliu,pu,i (n) represents the true space distance, ionospheric delay and tropospheric delay of the up - link pseudo - range signal between the self - transmitting and self - receiving end numbered i and the satellite;

[0035] R true,pd,i (n), I pd,i (n), T duiliu,pd,i (n) represents the true space distance, ionospheric delay and tropospheric delay of the down - link pseudo - range signal between the relay end numbered i and the satellite;

[0036] sagnac zz (n) is the Sagnac effect of the up - link pseudo - range signal between the self - transmitting and self - receiving end and the satellite, sagnac uu (n) is the Sagnac effect of the down - link pseudo - range signal between the relay end and the satellite.

[0037] When the relay end emits and the self - transmitting and self - receiving end receives the long pseudo - range ranging signal, the subscript of the up - link part of the long pseudo - range ranging value is still represented by pd. At this time, the up - link pseudo - range signal passes through the ionosphere between the relay end and the satellite. The subscript of the down - link part of the long pseudo - range ranging value is still represented by pu. At this time, the down - link pseudo - range signal passes through the ionosphere between the self - transmitting and self - receiving end and the satellite.

[0038] sagnac zz (n) is the Sagnac effect of the up - link pseudo - range signal between the relay end and the satellite, sagnac uu (n) is the Sagnac effect of the down - link pseudo - range signal between the self - transmitting and self - receiving end and the satellite.

[0039] R true,pd,i (n), I pd,i (n), T duiliu,pd,i (n) represents the true space distance, ionospheric delay and tropospheric delay of the up - link pseudo - range signal between the relay end numbered i and the satellite;

[0040] R true,pu,i (n), I pu,i (n), T duiliu,pu,iThe (n) represents the true spatial distance, ionospheric delay, and tropospheric delay of the pseudorange downlink signal between the self-transmitting and self-receiving end numbered i and the satellite;

[0041] Therefore, whether it is the self-transmitting and self-receiving end measuring or the relay end measuring the long pseudorange ranging signal, the same formula (u1) is used for representation.

[0042] ρ p,mean The (n) represents the corrected average long pseudorange ranging value at the nth moment, unit: meter; ρ p,1,a The (n) represents the first corrected long pseudorange ranging value at the nth moment, unit: meter; ρ p,1 The (n) represents the first long pseudorange ranging value, unit: meter; R true,pu,1 (n), R true,pd,1 The (n) represents the true spatial distance passed by the pseudorange uplink signal and / or pseudorange downlink signal of the first long pseudorange ranging signal at the nth moment, unit: meter; I pu,1 (n), I pd,1 The (n) represents the ionospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the first long pseudorange ranging signal at the nth moment, unit: meter; T duiliu,pu,1 (n), T duiliu,pd,1 The (n) represents the tropospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the first long pseudorange ranging signal at the nth moment, unit: meter; c represents the speed of light, unit: meter / second; δt z The (n) represents the clock offset of the self-transmitting and self-receiving end relative to the system time at the nth moment, unit: second; δt u The (n) represents the clock offset of the relay end relative to the system time at the nth moment, unit: second; sagnac zz The (n) represents the Sagnac effect delay of the pseudorange uplink signal at the nth moment, unit: meter; sagnac uu The (n) represents the Sagnac effect delay of the pseudorange downlink signal at the nth moment, unit: meter; X p,1 The (n) represents the hardware device delay of the first long pseudorange ranging signal at the nth moment, unit: meter, and the hardware device delay of the long pseudorange ranging signal includes the transmission delay of the pseudorange uplink signal of the first long pseudorange ranging signal and the reception delay of the pseudorange downlink signal of the first long pseudorange ranging signal;

[0043] L z,mean The (n) represents the corrected average master relay ranging value at the nth moment, unit: meter; L z,1,a The (n) represents the corrected master relay ranging value numbered 1 at the nth moment, unit: meter; L z,1 The (n) represents the master relay ranging value numbered 1 at the nth moment, unit: meter; R true,zu,1 (n), R true,zd,1(n) represents the true space distances traveled by the main uplink signal and the main downlink signal in the main forward ranging signal numbered 1 at the nth moment, unit: meter; I zu,1 (n), I zd,1 (n) represents the ionospheric delays of the main uplink signal and the main downlink signal in the main forward ranging signal numbered 1 at the nth moment, unit: meter; T duiliu,zu,1 (n), T duiliu,zd,1 (n) represents the tropospheric delays of the main uplink signal and the main downlink signal in the main forward ranging signal numbered 1 at the nth moment, unit: meter; Y z,1 (n) represents the hardware device delay of the main forward ranging signal numbered 1 at the nth moment, unit: meter. The hardware device delay of the main forward ranging signal includes the transmission delay of the main uplink signal numbered 1, the forwarding delay of the main downlink signal numbered 1 generated by the satellite, and the reception delay of the main downlink signal numbered 1;

[0044] L u,mean (n) represents the corrected average ranging value from the forward ranging at the nth moment, unit: meter; L u,1,a (n) represents the corrected ranging value from the forward ranging numbered 1 at the nth moment, unit: meter; L u,1 (n) represents the ranging value from the forward ranging numbered 1 at the nth moment, unit: meter; R true,uu,1 (n), R true,ud,1 (n) represents the true space distances traveled by the slave uplink signal and the slave downlink signal in the slave forward ranging signal numbered 1 at the nth moment, unit: meter; I uu,1 (n), I ud,1 (n) represents the ionospheric delays of the slave uplink signal and the slave downlink signal in the slave forward ranging signal numbered 1 at the nth moment, unit: meter; T duiliu,uu,1 (n), T duiliu,ud,1 (n) represents the tropospheric delays of the slave uplink signal and the slave downlink signal in the slave forward ranging signal numbered 1 at the nth moment, unit: meter; Y u,1 (n) represents the hardware device delay of the slave forward ranging signal numbered 1 at the nth moment, unit: meter. The hardware device delay of the slave forward ranging signal includes the transmission delay of the slave uplink signal numbered 1, the forwarding delay of the slave downlink signal numbered 1 generated by the satellite, and the reception delay of the slave downlink signal numbered 1;

[0045] L on,mean (n) represents the corrected average long forward ranging value at the nth moment, unit: meter; L on,1,a (n) represents the first corrected long forward ranging value at the nth moment, unit: meter; L u,1 (n) represents the first long forward ranging value at the nth moment, unit: meter; R true,uu,1 (n), Rtrue,ud,1 (n) represents the true space distance traveled by the uplink and downlink signals between the transponder and the satellite in the first long transponder ranging signal at the nth moment, unit: meter; I uu,1 (n), I ud,1 (n) represents the ionospheric delay of the uplink and downlink signals between the transponder and the satellite in the first long transponder ranging signal at the nth moment, unit: meter; T duiliu,uu,1 (n), T duiliu,ud,1 (n) represents the tropospheric delay of the uplink and downlink signals between the transponder and the satellite in the first long transponder ranging signal at the nth moment, unit: meter; R true,zu,1 (n), R true,zd,1 (n) represents the true space distance traveled by the uplink and downlink signals between the self - transmitting and self - receiving end and the satellite in the first long transponder ranging signal at the nth moment, unit: meter; I zu,1 (n), I zd,1 (n) represents the ionospheric delay of the uplink and downlink signals between the self - transmitting and self - receiving end and the satellite in the first long transponder ranging signal at the nth moment, unit: meter; T duiliu,zu,1 (n), T duiliu,zd,1 (n) represents the tropospheric delay of the uplink and downlink signals between the self - transmitting and self - receiving end and the satellite in the first long transponder ranging signal at the nth moment, unit: meter; Y on,1 (n) represents the hardware device delay of the first long transponder ranging signal at the nth moment, unit: meter, and the hardware device delay includes the transmission and reception delays of the self - transmitting and self - receiving end for the first uplink signal and the second downlink signal in the first long transponder ranging signal, and the transponder delay of the satellite and the transponder for the first long transponder ranging signal.

[0046] ±(δt u (n) - δt z (n)) c represents the relative clock difference between the self - transmitting and self - receiving end and the transponder calculated at the nth moment, unit: second

[0047] Q ion represents the ionospheric delay coefficient;

[0048] TEC z (n) represents the total electron number of the ionosphere between the satellite and the self - transmitting and self - receiving end at the nth moment, unit: electrons per square meter; TEC u (n) represents the total electron number of the ionosphere between the transponder and the satellite at the nth moment, unit: electrons per square meter;

[0049] f pu,1 (n), f pu,2(n) represents the carrier frequency of the pseudo-range downlink signal or pseudo-range uplink signal between the satellite and the self-transmitting and self-receiving end in the long pseudo-range ranging signals numbered 1 and 2 at the nth moment; f pd,1 (n), f pd,2 (n) represents the carrier frequency of the pseudo-range downlink signal or pseudo-range uplink signal between the satellite and the transponder in the long pseudo-range ranging signals numbered 1 and 2 at the nth moment, unit: Hertz; f zu,1 (n), f zd,1 (n) represents the carrier frequency of the first uplink signal, the second downlink signal between the satellite and the self-transmitting and self-receiving end of the long retransmission ranging signal numbered 1 at the nth moment, or the main uplink signal and main downlink signal of the main retransmission ranging signal numbered 1, unit: Hertz; f uu,1 (n), f ud,1 (n) represents the carrier frequency of the second uplink signal, the first downlink signal between the satellite and the transponder of the long retransmission ranging signal numbered 1 at the nth moment, or the slave uplink signal and slave downlink signal of the slave retransmission ranging signal numbered 1, unit: Hertz.

[0050] It should be specifically pointed out that: Q ion is the ionospheric delay coefficient, which is released by some international institutions. As the research on ionospheric delay deepens, the ionospheric delay coefficient becomes more and more accurate. The ionospheric delay coefficient was once 40.28, 40.30, and currently it is 40.309. There may be a more accurate ionospheric delay coefficient in the future. This application does not make special limitations on the ionospheric delay coefficient and takes the latest released value. In this exemplary embodiment, Q ion takes the value of 40.309.

[0051] The novel high-precision retransmission satellite time synchronization system provided by this application includes a satellite, a self-transmitting and self-receiving end, a transponder, and a computing device. The self-transmitting and self-receiving end and the transponder are both communicatively connected to the satellite, and the computing device is communicatively connected to the self-transmitting and self-receiving end and the transponder.

[0052] Among them, the computing device can communicate with the self-transmitting and self-receiving end and the transponder respectively to obtain long pseudo-range ranging values and long retransmission ranging values; or, the computing device can communicate with the self-transmitting and self-receiving end and the transponder respectively to obtain long pseudo-range ranging values, main retransmission ranging values, and slave retransmission ranging values.

[0053] The computing device obtains various measurement values, and according to the relationship between the measurement values and two preset carrier frequencies, executes the method of this application to calculate the relative clock difference between the self-transmitting and self-receiving end and the transponder.

[0054] It should be noted that in the embodiments of this application, the computing device can be integrated into the self-transmitting and self-receiving end; or integrated into the transponder; or it can also be independent of the self-transmitting and self-receiving end and the transponder; or be dispersed in the self-transmitting and self-receiving end and the transponder to perform calculations respectively, or be an independent device.

[0055] Since the function of the computing device is calculated based on the long forward ranging value and the long pseudorange ranging value, which is not the core function of this application. Therefore, this application focuses on describing the new high-precision forward satellite time synchronization system and various calculation methods.

[0056] For the new high-precision forward satellite time synchronization system of this application, by combining the characteristics of the long pseudorange ranging signal, the long forward ranging signal, and the satellite transponder, or by combining the long pseudorange ranging signal, the main forward ranging signal, the slave forward ranging signal, and the transponder characteristics, a new high-precision forward satellite time synchronization system is creatively proposed, which can obtain the relative clock difference between the self-transmitting and self-receiving end and the transponder end.

[0057] To implement the functions of this application, the new high-precision forward satellite time synchronization system provided by this application has two system forms.

[0058] The first new high-precision forward satellite time synchronization system: There are m long pseudorange ranging signals between the self-transmitting and self-receiving end, the satellite, and the transponder end, h main forward ranging signals between the self-transmitting and self-receiving end and the satellite, and r slave forward ranging signals between the transponder end and the satellite. Measuring these signals respectively obtains m long pseudorange ranging values, h main forward ranging values, and r slave forward ranging values. Using the m long pseudorange ranging values, h main forward ranging values, r slave forward ranging values, and the first preset carrier frequency relationship to determine the relative clock difference between the self-transmitting and self-receiving end and the transponder end;

[0059] The second new high-precision forward satellite time synchronization system: There are s long forward ranging signals and m long pseudorange ranging signals between the self-transmitting and self-receiving end, the satellite, and the transponder end. Measuring these signals respectively obtains m long pseudorange ranging values and s long forward ranging values. Using the m long pseudorange ranging values and s long forward ranging values, and the second preset carrier frequency relationship to determine the relative clock difference between the self-transmitting and self-receiving end and the transponder end;

[0060] Where m, h, r, and s are all positive integers greater than or equal to 1.

[0061] It should be particularly noted that: in the second new high-precision forward satellite time synchronization system, the long forward ranging signal is transmitted, received, and measured by the self-transmitting and self-receiving end to obtain the long forward ranging value. The computing device communicates with the self-transmitting and self-receiving end to obtain the long forward ranging value.

[0062] In the two new high-precision forward satellite time synchronization systems, the long pseudorange ranging signal can be transmitted by the self-transmitting and self-receiving end and received by the transponder end, or transmitted by the transponder end and received by the self-transmitting and self-receiving end.

[0063] For the above two forms of the new high-precision forward satellite time synchronization system, there are two simplest systems, respectively:

[0064] The simplest system of the first new type of high-precision retransmitting satellite time transfer system: There is 1 long pseudo-range ranging signal among the self-transmitting and self-receiving end, the satellite, and the retransmitting end. There is 1 main retransmitting ranging signal between the self-transmitting and self-receiving end and the satellite, and 1 slave retransmitting ranging signal between the retransmitting end and the satellite. Measuring these signals respectively obtains 1 long pseudo-range ranging value, 1 main retransmitting ranging value, and 1 slave retransmitting ranging value. Using 1 long pseudo-range ranging value, 1 main retransmitting ranging value, 1 slave retransmitting ranging value, and the first preset carrier frequency relationship to determine the relative clock difference between the self-transmitting and self-receiving end and the retransmitting end. At this time, m = 1, h = 1, r = 1;

[0065] The simplest system of the second new type of high-precision retransmitting satellite time transfer system: There is 1 long retransmitting ranging signal and 1 long pseudo-range ranging signal among the self-transmitting and self-receiving end, the satellite, and the retransmitting end. Measuring these signals respectively obtains 1 long pseudo-range ranging value and 1 long retransmitting ranging value. Using 1 long pseudo-range ranging value and 1 long retransmitting ranging value, and the second preset carrier frequency relationship to determine the relative clock difference between the self-transmitting and self-receiving end and the retransmitting end. At this time, m = 1, s = 1.

[0066] Because the long retransmitting ranging signal in this application can be regarded as formed by connecting the main retransmitting ranging signal and the slave retransmitting ranging signal, the carrier frequency of the signal between the satellite and the self-transmitting and self-receiving end in the long retransmitting ranging signal is represented by the same symbol as the carrier frequency of the main retransmitting ranging signal; the carrier frequency of the signal between the satellite and the retransmitting end in the long retransmitting ranging signal is represented by the same symbol as the carrier frequency of the slave retransmitting ranging signal. This representation is more concise and easy to understand.

[0067] At the same time, for easier understanding, the carrier frequencies of the ranging signals between the self-transmitting and self-receiving end and the satellite are represented by fzu and fzd, while the carrier frequencies of the ranging signals between the retransmitting end and the satellite are represented by fuu and fud. Therefore, when expressing the long retransmitting ranging value, the main retransmitting ranging value, and the slave retransmitting ranging value using formulas, the frequency symbols used are the same.

[0068] In addition, the first uplink signal between the self-transmitting and self-receiving end and the satellite of the long retransmitting ranging signal can also be called the main uplink signal, and the second downlink signal can also be called the main downlink signal, with the same names as the main uplink signal and the main downlink signal of the main retransmitting ranging signal; the second uplink signal between the retransmitting end and the satellite of the long retransmitting ranging signal can also be called the slave uplink signal, and the first downlink signal can also be called the slave downlink signal, with the same names as the slave uplink signal and the slave downlink signal of the slave retransmitting ranging signal.

[0069] For the typical system of the first new type of high-precision retransmitting satellite timekeeping system, this application uses a signal structure with one long pseudo-range ranging signal, one main retransmitting ranging signal, and one slave retransmitting ranging signal, and the carrier frequencies of all signals are different from each other for exemplary illustration. At this time, m = 1, h = 1, r = 1, Figure 1 FIG. is a schematic structural diagram of the typical system of the first new type of high-precision retransmitting satellite timekeeping system provided by the embodiment of this application, as Figure 1 shown, a long pseudo-range ranging value, a main retransmitting ranging value, and a slave retransmitting ranging value are measured.

[0070] For the typical system of the second new type of high-precision retransmitting satellite timekeeping system, this application uses a signal structure with one long retransmitting ranging signal and one long pseudo-range ranging signal, and the carrier frequencies of all signals are different from each other for exemplary illustration. At this time, m = 1, s = 1, Figure 2 FIG. is a schematic structural diagram of the typical system of the second new type of high-precision retransmitting satellite timekeeping system provided by the embodiment of this application, as Figure 2 shown, a long retransmitting ranging value and a long pseudo-range ranging value are measured.

[0071] Therefore Figure 1 and Figure 2 the signal structures shown are very representative, and timekeeping that completely overcomes the ionospheric delay error can be achieved using fewer frequency resources. This example is used to illustrate the system structure and execution method of this application.

[0072] Next, the new type of high-precision retransmitting satellite timekeeping system and its related methods provided by the embodiments of this application will be introduced in detail with reference to the accompanying drawings.

[0073] This application provides two forms of new type of high-precision retransmitting satellite timekeeping systems. Both new type of high-precision retransmitting satellite timekeeping systems include a self-transmitting and self-receiving end 210, a satellite 100, a retransmitting end 220, and a computing device, and there is at least one long pseudo-range ranging signal among the three. The long pseudo-range ranging signal is composed of a pseudo-range uplink signal and a pseudo-range downlink signal. The self-transmitting and self-receiving end 210 broadcasts the pseudo-range uplink signal, the satellite 100 retransmits the pseudo-range uplink signal to form a pseudo-range downlink signal, and the retransmitting end 220 receives the pseudo-range downlink signal. Or, the retransmitting end 220 broadcasts the pseudo-range uplink signal, the satellite 100 retransmits the pseudo-range uplink signal to form a pseudo-range downlink signal, and the self-transmitting and self-receiving end 210 receives the pseudo-range downlink signal.

[0074] Next, without special explanation, the example where the self-transmitting and self-receiving end 210 broadcasts the pseudo-range uplink signal and the retransmitting end 220 receives the pseudo-range downlink signal will be used for exemplary illustration.

[0075] Among them, the long pseudo-range ranging signal is composed of a pseudo-range uplink signal and a pseudo-range downlink signal. The pseudo-range uplink signal is broadcast by the self-transmitting and self-receiving end 210 or the forwarding end 220. The satellite 100 forwards the pseudo-range uplink signal into the pseudo-range downlink signal, and the forwarding end 220 or the self-transmitting and self-receiving end 210 receives the pseudo-range downlink signal;

[0076] The long forwarding ranging signal is composed of a first uplink signal broadcast by the self-transmitting and self-receiving end 210, a first downlink signal formed by the satellite 100 receiving and forwarding the first uplink signal, a second uplink signal formed by the forwarding end 220 receiving and forwarding the first downlink signal, and a second downlink signal formed by the satellite 100 receiving the second uplink signal and forwarding it to the self-transmitting and self-receiving end 210;

[0077] The main forwarding ranging signal is composed of a main uplink signal and a main downlink signal. The self-transmitting and self-receiving end 210 broadcasts the main uplink signal and receives the main downlink signal, and the satellite 100 receives the main uplink signal and forwards it to form the main downlink signal;

[0078] The slave forwarding ranging signal is composed of a slave uplink signal and a slave downlink signal. The forwarding end 220 broadcasts the slave uplink signal and receives the slave downlink signal, and the satellite 100 receives the slave uplink signal and forwards it to form the slave downlink signal.

[0079] In the first new type of high-precision forwarding satellite time synchronization system, there are m paths of long pseudo-range ranging signals between the satellite 100 and the self-transmitting and self-receiving end 210, h paths of main forwarding ranging signals, and r paths of slave forwarding ranging signals between the satellite 100 and the forwarding end 220. Among them, the carrier frequencies of the m paths of long pseudo-range ranging signals, the carrier frequencies of the h paths of main forwarding ranging signals, and the carrier frequencies of the r paths of slave forwarding ranging signals satisfy a first preset carrier frequency relationship. The signals between the self-transmitting and self-receiving end 210 and the satellite 100, and the signals between the forwarding end 220 and the satellite 100 all have at least two different carrier frequencies. m, h, and r are all positive integers greater than or equal to 1.

[0080] Taking Figure 1 the typical system shown as an example, the long pseudo-range ranging signal, the main forwarding ranging signal, and the slave forwarding ranging signal are all one path. Correspondingly, a main forwarding ranging value and a slave forwarding ranging value are measured. Then, based on 1 long pseudo-range ranging value, 1 long pseudo-range ranging value, 1 main forwarding ranging value, 1 slave forwarding ranging value, and the first preset carrier frequency relationship, the relative clock difference between the self-transmitting and self-receiving end 210 and the forwarding end 220 is obtained; Figure 1Among them, there are three different carrier frequencies between the satellite and the self-transmitting and self-receiving end. When there are two different carrier frequencies, the main uplink signal of the main forwarding ranging signal and the pseudorange uplink signal share the same path. When the pseudorange uplink signal reaches the satellite, it is split into two paths. One path is forwarded as the pseudorange downlink signal, and the other path is forwarded as the main downlink signal. There are three different carrier frequencies between the satellite and the forwarding end. When there are two different carrier frequencies, the downlink signal of the slave forwarding ranging signal and the pseudorange downlink signal perform carrier frequency multiplexing. After the slave uplink signal reaches the satellite, it is forwarded as the slave downlink signal and multiplexed with the pseudorange downlink signal in terms of carrier frequency.

[0081] In the second new type of high-precision forwarding satellite timing system, there are m long pseudorange ranging signals and s long forwarding ranging signals between the self-transmitting and self-receiving end 210, the satellite 100, and the forwarding end 220. Among them, the carrier frequencies of the m long pseudorange ranging signals and the carrier frequencies of the s long forwarding ranging signals satisfy the second preset carrier frequency relationship. Moreover, the signals between the self-transmitting and self-receiving end 210 and the satellite 100, and the signals between the forwarding end 220 and the satellite 100 all have at least two different carrier frequencies. Both m and s are positive integers greater than or equal to 1.

[0082] Taking Figure 2 the typical system shown as an example, there is 1 long pseudorange ranging signal and 1 long forwarding ranging signal between the self-transmitting and self-receiving end 210, the satellite 100, and the forwarding end 220. Correspondingly, 1 long pseudorange ranging value and 1 long forwarding ranging value are measured. Then, based on 1 long pseudorange ranging value, 1 long forwarding ranging value, and the second preset frequency relationship, the relative clock difference between the self-transmitting and self-receiving end 210 and the forwarding end 220 is calculated. Figure 2 Among them, there are three different carrier frequencies between the satellite and the self-transmitting and self-receiving end, and there are also three different carrier frequencies between the satellite and the forwarding end. When there are two different carrier frequencies on both sides, the first uplink signal of the long forwarding ranging signal and the pseudorange uplink signal share the same path, and the first downlink signal and the pseudorange downlink signal share the same path. When the pseudorange downlink signal reaches the forwarding end, it is split into two paths. One path is received by the forwarding end as the long pseudorange ranging signal, and the other path is forwarded as the second uplink signal. The second uplink signal is then forwarded by the satellite as the second downlink signal and received by the self-transmitting and self-receiving end.

[0083] When the computing device is integrated into the forwarding end 220, for Figure 1 and Figure 2 the two new types of high-precision forwarding satellite timing systems shown, the computing device obtains the long pseudorange ranging value, the main forwarding ranging value, and the slave forwarding ranging value through the communication method, or obtains the long forwarding ranging value and the long pseudorange ranging value.

[0084] In this application, since the long pseudo-range ranging signal, the long retransmitted ranging signal, the primary retransmitted ranging signal, and the secondary retransmitted ranging signal are all signals obtained by modulating a carrier frequency with a ranging code, for the sake of clear and concise description, these signals are collectively referred to as ranging signals.

[0085] It should be noted that the long pseudo-range ranging signal, the long retransmitted ranging signal, the primary retransmitted ranging signal, and the secondary retransmitted ranging signal described in this exemplary embodiment refer to spread spectrum signals obtained by modulating a carrier frequency with a ranging code. In some specific embodiments, the ranging code can be a pseudo-code, Weil code, M code, etc., and no special limitation is imposed on the specific selection of the ranging code in this application. And it can be understood that the long pseudo-range ranging signal, the long retransmitted ranging signal, the primary retransmitted ranging signal, and the secondary retransmitted ranging signal described in the embodiments of this application are all spread spectrum signals. When multiple spread spectrum signals are transmitted and received, the relationship between the carrier frequency and the ranging code is processed according to spread spectrum communication technology, carrier frequency multiplexing, and code division multiple access communication technology, which will not be elaborated here.

[0086] Generally, the first preset carrier frequency relationship refers to the frequency relationship satisfied among the carrier frequencies of m long pseudo-range ranging signals, the carrier frequencies of h primary retransmitted ranging signals, and the carrier frequencies of r secondary retransmitted ranging signals as shown in formula (f1):

[0087]

[0088] In Figure 1 In the shown typical system, there is m = 1 long pseudo-range ranging signal, h = 1 primary retransmitted ranging signal, and r = 1 secondary retransmitted ranging signal, and formula (f1) specifically becomes formula (f1-1):

[0089]

[0090] The second preset carrier frequency relationship refers to the frequency relationship satisfied between the carrier frequencies of m long pseudo-range ranging signals and the carrier frequencies of s long retransmitted ranging signals as shown in formula (f2):

[0091]

[0092] V = 1e-12.

[0093] In Figure 2 In the shown typical system, there is m = 1 long pseudo-range ranging signal and s = 1 long retransmitted ranging signal, and formula (f2) specifically becomes formula (f2-1):

[0094]

[0095] According to formula (f1-1) and formula (f2-1), it can be seen that the first preset carrier frequency relationship and the second preset carrier frequency relationship are the same.

[0096] Further, in some embodiments, the carrier frequency of the long forward ranging signal and the carrier frequency of the long pseudorange ranging signal hop on the time axis according to a preset frequency hopping pattern, or the carrier frequency of the long pseudorange ranging signal, the carrier frequency of the main forward ranging signal, and the carrier frequency of the slave forward ranging signal hop on the time axis according to a preset frequency hopping pattern. That is, the signals used at different times are not the same fixed frequency. By frequency hopping the signals in this way, the anti-interference ability of the signals can be improved, and the anti-interception ability of the signals can be enhanced.

[0097] It should be noted that no matter how the frequency hopping is performed, the carrier frequency of the long pseudorange ranging signal, the carrier frequency of the main forward ranging signal, and the carrier frequency of the slave forward ranging signal still need to satisfy the relational expression (f1), or the carrier frequency of the long pseudorange ranging signal and the carrier frequency of the long forward ranging signal still need to satisfy the relational expression (f2).

[0098] Of course, the carrier frequency of the long forward ranging signal and the carrier frequency of the long pseudorange ranging signal can also remain unchanged for a long time, or the carrier frequency of the long pseudorange ranging signal, the carrier frequency of the main forward ranging signal, and the carrier frequency of the slave forward ranging signal can also remain unchanged for a long time, that is, the time interval between two adjacent frequency hops is infinite.

[0099] When the novel high-precision forward satellite time service system provided by the embodiments of the present application is used to provide time service for the forward end 220, the forward end 220 can be a base station in the field of mobile communication, etc.

[0100] Figure 4 It is a schematic structural composition diagram of a satellite, a self-transmitting and self-receiving end, and a forward end according to an embodiment of the present application. Figure 5 It is a schematic structural composition diagram of a satellite, a self-transmitting and self-receiving end, and a forward end according to another embodiment of the present application. As Figure 4 and Figure 5 shown, in an exemplary embodiment, the satellite 100 may include a transponder 101 and a satellite time-frequency device 103. The satellite time-frequency device 103 may provide time-frequency signals for the transponder 101; the transponder 101 may forward several received pseudorange uplink signals into several pseudorange downlink signals; forward the received main uplink signal into a main downlink signal, and forward the received slave uplink signal into a slave downlink signal. In addition, forward the first uplink signal in the long forward ranging signal into the first downlink signal and forward the second uplink signal into the second downlink signal.

[0101] Specifically, the transponder 101 is mainly used to perform frequency conversion processing and power amplification on various obtained uplink signals and then forward them. In this embodiment, the transponder 101 performs frequency conversion processing and power amplification on the pseudorange uplink signals in each long pseudorange ranging signal and then forwards them into corresponding pseudorange downlink signals.

[0102] Furthermore, the transponder 101 performs transponder processing on the master transponder ranging signal and the slave transponder ranging signal. Also, when the self-transmitting and self-receiving end 210 broadcasts a long transponder ranging signal, the corresponding signal is transponded.

[0103] It should be understood that the transponder 101 and the satellite time-frequency device 103 described in the embodiments of the present application can be independently set, or can also be integrated in a hardware device, that is, implemented through an integrated hardware device, and these all fall within the protection scope of the present application.

[0104] The structure diagram of the first new type of high-precision transponder-based satellite time service system can be referred to Figure 4 , the long pseudo-range ranging signal is transmitted by the self-transmitting and self-receiving end and received by the transponder end. The transponder end 220 may include: a slave transponder ranging device 221, a slave pseudo-range ranging device 222, and at least one slave time-frequency device 223, where

[0105] The slave transponder ranging device 221 is used to broadcast the slave uplink signal and receive the slave downlink signal to obtain the slave transponder ranging value;

[0106] The slave pseudo-range ranging device 222 is used to receive the pseudo-range downlink signal and measure the long pseudo-range ranging value. At this time, the long pseudo-range ranging signal is broadcast by the self-transmitting and self-receiving end 210; or, the slave pseudo-range ranging device 222 is used to broadcast the pseudo-range uplink signal.

[0107] The slave time-frequency device 223 is used to provide time-frequency signals to the slave pseudo-range ranging device 222 and the slave transponder ranging device 221.

[0108] The self-transmitting and self-receiving end 210 includes: a master transponder ranging device 211, a master pseudo-range ranging device 212, and at least one master time-frequency device 213, where

[0109] The master transponder ranging device 211 is used to broadcast the master uplink signal, receive and measure the master downlink signal to obtain the master transponder ranging value, and broadcast the pseudo-range uplink signal;

[0110] The master pseudo-range ranging device 212 is used to receive the pseudo-range downlink signal and measure the long pseudo-range ranging value. At this time, the long pseudo-range ranging signal is broadcast by the transponder end 220; or, the master pseudo-range ranging device 212 is used to broadcast the pseudo-range uplink signal.

[0111] The master time-frequency device 213 is used to provide time-frequency signals to the master transponder ranging device 211 and the master pseudo-range ranging device 212.

[0112] It should be noted that in Figure 4In the exemplary embodiment shown, the at least one slave time-frequency device may include multiple clocks (crystal oscillators or atomic clocks) or one clock (crystal oscillator or atomic clock). When multiple clocks are included, one clock provides a clock signal to the slave pseudorange ranging device 222, and the remaining clocks provide clock signals to the slave transponder ranging device 221. In actual use, the slave pseudorange ranging device 222 and the slave transponder ranging device 221 perform measurements at a predetermined time interval, which can be set to 1 s, for example. The slave pseudorange ranging device 222 and the slave transponder ranging device 221 perform synchronous measurements at the rising or falling edge of their own 1PPS (1 Pulse Per Second) signal. Preferably, it is generally recommended to use one clock, that is, the slave transponder ranging device 221 and the slave pseudorange ranging device 222 use a common 1PPS signal for measurement.

[0113] The main transponder ranging device 211 and the main pseudorange ranging device 212 of the self-transmitting and self-receiving end 210 perform measurements of the main transponder ranging value and the long pseudorange ranging value under the 1PPS signal provided by the main time-frequency device 213.

[0114] In addition, it should be noted that the slave pseudorange ranging device 222, the slave transponder ranging device 221, the slave time-frequency device 223, and the computing device 224 included in the transponder end 220 can be set independently or integratedly, and these all fall within the protection scope of this application.

[0115] The main pseudorange ranging device 212 and the slave pseudorange ranging device 222 include a receiving antenna and a receiver. The receiving antenna receives the corresponding pseudorange signal and performs measurements.

[0116] In the exemplary embodiment, both the slave transponder ranging device 221 and the main transponder ranging device 211 may include a modulator, a mixer, a demodulator, an antenna, a data collector, etc. The modulator generates an intermediate-frequency spread-spectrum signal; the mixer mixes the intermediate-frequency spread-spectrum signal to a radio-frequency signal, and the antenna transmits the radio-frequency signal to the satellite 100 and receives the radio-frequency signal forwarded by the satellite 100. The antenna receives the radio-frequency signal and the mixer mixes it to an intermediate-frequency signal; the demodulator demodulates the intermediate-frequency signal, and obtains the corresponding long transponder ranging value through ranging code correlation operations; the data collector records and stores the long transponder ranging value.

[0117] The slave pseudorange ranging device 222 includes a receiving antenna and a receiver. The receiving antenna receives the pseudorange downlink signal forwarded by the satellite 100, and the slave pseudorange ranging device 222 generates a long pseudorange ranging value.

[0118] The main pseudorange ranging device 212 includes a receiving antenna and a receiver. The receiving antenna receives the pseudorange downlink signal forwarded by the satellite 100, and the main pseudorange ranging device 212 generates a long pseudorange ranging value.

[0119] The structure of the second new high-precision retransmission satellite timekeeping system can be referred to Figure 5 , and the self-transmitting and self-receiving end 210 may include: a main retransmission ranging device 211, at least one main time-frequency device 213, and a main pseudorange ranging device 212.

[0120] In Figure 5 , the long pseudorange ranging signal is transmitted by the retransmission end 220 and received and measured by the self-transmitting and self-receiving end 210;

[0121] Continuing to refer to Figure 5 , the main retransmission ranging device 211 is used to broadcast the first uplink signal and receive the second downlink signal, and measure s long retransmission ranging values from the s-channel long retransmission ranging signal;

[0122] The main pseudorange ranging device 212 receives the long pseudorange ranging signal and measures to obtain m long pseudorange ranging values;

[0123] The main time-frequency device 213 is used to provide time-frequency signals to the main retransmission ranging device 211 and the main pseudorange ranging device 212;

[0124] In addition, it should be noted that the main time-frequency device 213, the main retransmission ranging device 211, and the main pseudorange ranging device 212 may be independently set or integrated, and these all fall within the protection scope of this application.

[0125] Continuing to refer to Figure 5 , the retransmission end 220 may include: a slave retransmission ranging device 221, a slave pseudorange ranging device 222, and at least one slave time-frequency device 223, where the slave retransmission ranging device 221 is used to receive the first downlink signal and forward it to form the second uplink signal.

[0126] The slave pseudorange ranging device 222 is used to receive the pseudorange downlink signal and measure to obtain long pseudorange ranging values. At this time, the long pseudorange ranging signal is broadcast by the self-transmitting and self-receiving end 210; alternatively, the slave pseudorange ranging device 222 is used to broadcast the pseudorange uplink signal.

[0127] The slave time-frequency device 223 is used to provide time-frequency signals to the slave retransmission ranging device 221 and the slave pseudorange ranging device 222;

[0128] Similarly, the slave time-frequency device 223, the slave retransmission ranging device 221, and the slave pseudorange ranging device 222 are integrated or separated.

[0129] In the embodiments of this application, the new high-precision retransmission satellite timekeeping system may further include a computing device 224. The computing device 224 may be integrated into the retransmission end 220 or the self-transmitting and self-receiving end 210. Figure 4 , Figure 5 Taking the integration of the computing device 224 into the retransmission end 220 as an example for illustration.

[0130] The computing device 224 is communicatively connected to the master pseudo-range ranging device 212 and the master transponder ranging device 211 respectively, obtains the long pseudo-range ranging value and the long transponder ranging value, and executes the method of this application to obtain the relative clock difference between the transponder 220 and the self-transmitting and self-receiving end 210.

[0131] The master transponder ranging device 211 may include a modulator, a mixer, a demodulator, an antenna, a data collector, etc. The modulator generates an intermediate-frequency spread-spectrum signal; the mixer mixes the intermediate-frequency spread-spectrum signal to a radio-frequency signal, and the antenna transmits the radio-frequency signal to the satellite 100 and receives the radio-frequency signal forwarded by the satellite 100. The antenna receives the radio-frequency signal and the mixer mixes it to an intermediate-frequency signal; the demodulator demodulates the intermediate-frequency signal, and obtains the long transponder ranging value through ranging code correlation operation; the data collector records and stores the long transponder ranging value.

[0132] Similarly, the master time-frequency device 213, the master transponder ranging device 211, and the master pseudo-range ranging device 212 are integrally or separately arranged;

[0133] It should be noted that in Figure 5 In the shown exemplary embodiment, the at least one master time-frequency device may include multiple clocks (crystal oscillators or atomic clocks) or one clock (crystal oscillator or atomic clock). When multiple clocks are included, one clock provides a clock signal for the master pseudo-range ranging device 212, and the remaining clocks provide clock signals for the master transponder ranging device 211. In actual use, the master pseudo-range ranging device 212 and the master transponder ranging device 211 perform measurements at a predetermined time interval. The preset time interval can be set to 1 s, for example. The master pseudo-range ranging device 212 and the master transponder ranging device 211 perform synchronous measurements at the rising or falling edge of their own 1PPS (1 Pulse Per Second) signal. Preferably, it is generally recommended to use one clock, that is, the master transponder ranging device 211 and the master pseudo-range ranging device 212 use a common 1PPS signal for measurement.

[0134] In this exemplary embodiment, for Figure 4 the transponder 220, the slave pseudo-range ranging device 222 and the slave transponder ranging device 221 are set with a zero baseline. For Figure 5 the self-transmitting and self-receiving end 210, the master pseudo-range ranging device 212 and the master transponder ranging device 211 are set with a zero baseline.

[0135] It should be noted that the zero baseline setting in this application does not mean that the distance between the slave pseudorange ranging device 222 and the slave transponder ranging device 221 is 0. Instead, the distance setting between them should satisfy that the spatial paths experienced by the slave uplink signal / slave downlink signal and the pseudorange uplink signal between the satellite 100 and the transponder 220 are approximately the same, or the spatial paths experienced by the transponder ranging signal and the pseudorange downlink signal are approximately the same. When the distance between the slave pseudorange ranging device 222 and the slave transponder ranging device 221 becomes smaller and smaller and can be integrated into one device, the approximate sameness gradually becomes sameness, with the same space distance between the satellite and the ground, the same tropospheric delay, and the same total electron content of the ionosphere.

[0136] For the self-transmitting and self-receiving end 210, the zero baseline setting of the master pseudorange ranging device 212 and the master transponder ranging device 211 is for the same reason as the zero baseline setting of the slave pseudorange ranging device 222 and the slave transponder ranging device 221 above, that is, the spatial paths experienced by the master uplink signal / master downlink signal and the pseudorange uplink signal between the satellite 100 and the self-transmitting and self-receiving end 210 are approximately the same. Therefore, there are also the same space distance between the satellite and the ground, the same tropospheric delay, and the same total electron content of the ionosphere.

[0137] During the process of the transponder 101 forwarding the signal, satellite transponder delay will be generated. The satellite transponder delay includes the transponder delay when the pseudorange uplink signal becomes the pseudorange downlink signal after passing through the transponder 101, and the transponder delays experienced by the master transponder ranging signal, the slave transponder ranging signal, and the long transponder ranging signal through the satellite 100.

[0138] It should be noted that in this exemplary embodiment, during the communication between the self-transmitting and self-receiving end 210 and the satellite 100, the satellite 100 can first transmit the transponder delay of the satellite 100 to the self-transmitting and self-receiving end 210 by adding a communication signal. Thus, the self-transmitting and self-receiving end 210 can obtain the transponder delay of the satellite 100. Then, the self-transmitting and self-receiving end 210 uses the long pseudorange ranging signal to transmit the above-mentioned satellite transponder delay to the transponder 220.

[0139] In this exemplary embodiment, the self-transmitting and self-receiving end 210 has a self-transmitting and self-receiving end device delay, which includes the transmission delay of the master pseudorange ranging device 212 for transmitting the pseudorange uplink signal; the transmission, reception, and transponder delays of the master transponder ranging device 211 when processing the long transponder ranging signal or the master transponder ranging signal.

[0140] In this exemplary embodiment, the transponder 220 has a transponder device delay, which includes the reception delay of the slave pseudorange ranging device 222 for receiving the pseudorange downlink signal; the transmission, reception, or transponder delays of the slave transponder ranging device 221 when processing the long transponder ranging signal or the slave transponder ranging signal.

[0141] In an exemplary embodiment, the novel high-precision forwarding satellite time synchronization system provided by the embodiments of the present application further has a space-ground communication function. Based on Figure 1 or Figure 2 , satellite 100 uses the additional communication signal to perform data interaction with the self-transmitting and self-receiving end 210 or the forwarding end 220. The additional communication signal may be a telecommand and telemetry signal.

[0142] In this exemplary embodiment, during communication, the self-transmitting and self-receiving end 210 and the forwarding end 220 may be directly communicatively connected or perform data interaction through satellite 100. For example, in a city, the self-transmitting and self-receiving end 210 and the forwarding end 220 may directly communicate through a 4G network or a 5G network. Of course, the self-transmitting and self-receiving end 210 may also be communicatively connected to the forwarding end 220 through satellite 100. For example, in the sea or desert, both the self-transmitting and self-receiving end 210 and the forwarding end 220 are directly communicative with satellite 100, so as to realize communication between the self-transmitting and self-receiving end 210 and the forwarding end 220 through satellite 100.

[0143] The forwarding end 220 in the embodiments of the present application may be a base station, a radar, a Tianyan, etc. Moreover, there may be multiple forwarding ends 220 in the embodiments of the present application. For example, a communication operator may build a communication network based on this novel high-precision forwarding satellite time synchronization system. In this case, the forwarding end 220 may be a communication base station. The communication operator controls each communication base station through the self-transmitting and self-receiving end 210 and obtains relevant information of each communication base station based on the communication result between the self-transmitting and self-receiving end 210 and the communication base station.

[0144] It should be understood that in this exemplary embodiment, when the self-transmitting and self-receiving end 210 communicates with the forwarding end 220, the operating parameters of the forwarding end 220 can be obtained and the forwarding end 220 can be controlled to perform corresponding actions. Typically, an Internet of Things system can be built based on the novel high-precision forwarding satellite time synchronization system provided by the embodiments of the present application. The specific content of the operating parameters may be determined according to the needs of the user. For example, the operating parameters may include the clock difference of the forwarding end 220 relative to the system time, the location information of the forwarding end 220, the current temperature information at the location where the forwarding end 220 is located, etc.

[0145] The related methods provided by the embodiments of the present application will be specifically described below with reference to the accompanying drawings. Before the method description, the Sagnac effect time delay used in the present application will be described first.

[0146] It should be noted that in the embodiments of the present application, when calculating the relative clock difference between the self-transmitting and self-receiving end 210 and the forwarding end 220, the corresponding Sagnac effect time delay needs to be obtained. When calculating the relative clock difference between the forwarding end and the self-transmitting and self-receiving end, the Sagnac effect time delay requires the coordinates of the self-transmitting and self-receiving end 210, the forwarding end 220, and the satellite 100. The coordinates of the satellite 100 can be obtained from the known satellite ephemeris of the satellite 100, and the coordinates of the self-transmitting and self-receiving end 210 and the forwarding end 220 can be obtained through existing positioning methods. In this way, the coordinate information required by the method of the embodiments of the present application is obtained, and then the Sagnac effect time delay is obtained.

[0147] When using the long forwarding ranging expression to represent the long forwarding ranging value, there is no Sagnac effect time delay in the long forwarding ranging expression because the Sagnac effect time delay of the uplink signal and the Sagnac effect time delay of the downlink signal have opposite signs and the absolute value difference between the two is very small. Therefore, these two Sagnac effect time delays can be approximately cancelled, so that the Sagnac effect time delay term is not reflected in the long forwarding ranging expression.

[0148] Similarly, when using the forwarding ranging expression to represent the main forwarding ranging value and the slave forwarding ranging value (collectively referred to as the forwarding ranging value), there is no Sagnac effect time delay in the forwarding ranging expression because the Sagnac effect time delay of the uplink signal and the Sagnac effect time delay of the downlink signal have opposite signs and the absolute value difference between the two is very small. Therefore, these two Sagnac effect time delays can be approximately cancelled, so that the Sagnac effect time delay term is not reflected in the forwarding ranging expression. Of course, in some other embodiments of the present application, the Sagnac effect time delay can also be considered, that is, the Sagnac effect time delay of the uplink signal and the Sagnac effect time delay of the downlink signal are added to the forwarding ranging expression, or the Sagnac effect time delay is added to the long forwarding ranging expression, so as to obtain better measurement accuracy of the forwarding ranging value. These all belong to the protection scope of the present application.

[0149] It should be noted that the Sagnac effect time delay in the long pseudorange ranging expression and the long forwarding ranging expression of the present application has been described above and can be regarded as a known value, while the space distance between the satellite and the ground, the tropospheric delay, the ionospheric delay, and the relative clock difference between the self-transmitting and self-receiving end 210 and the forwarding end 220 are unknowns. The present application calculates the relative clock difference between the self-transmitting and self-receiving end and the forwarding end according to the measured long pseudorange ranging value, long forwarding ranging value, second preset carrier frequency relationship, or long pseudorange ranging value, main forwarding ranging value, slave forwarding ranging value, first preset carrier frequency relationship, and the method.

[0150] The ionosphere is a dispersive medium, that is, the time delay generated by the ionosphere for radio frequency signals of different carrier frequencies varies with the carrier frequency, while the troposphere is a non-dispersive medium, that is, the troposphere generates the same time delay for radio frequency signals of different carrier frequencies.

[0151] Due to the zero-baseline setting between the main pseudorange ranging device 212 and the main transponder ranging device 211, the uplink and downlink signals between the satellite 100 and the self-transmitting and self-receiving end 210 in the pseudorange uplink signal and the long transponder ranging signal pass through exactly the same atmospheric path, and the total number of electrons in the ionosphere experienced is exactly the same. However, the time when the uplink signal passes through the ionosphere is different from the time when the downlink signal passes through the ionosphere after being transponder by the satellite 100, with a certain time difference. In a relatively short period of time (such as several seconds), the ionosphere is stable and the total number of electrons in the ionosphere hardly changes. It can be estimated that the round-trip time of the radio frequency signal between the self-transmitting and self-receiving end 210 and the satellite 100 will not exceed several seconds either, fully meeting the conditions. The pseudorange uplink signal or pseudorange downlink signal between the satellite and the self-transmitting and self-receiving end also has the same spatial distance and tropospheric time delay relationship with the main transponder ranging signal. Combining the spatial relationship of the zero-baseline setting and the time relationship with a very short time difference, there are therefore equations (z19), (z20):

[0152] R true,pu,1 (n) = R true,pu,2 (n) = R true,zu,1 (n) = R true,zd,1 (n)(z19);

[0153] T duiliu,pu,1 (n) = T duiliu,pu,2 (n) = T duiliu,zu,1 (n) = T duiliu,zd,1 (n)(z20);

[0154] Because of the zero-baseline setting between the ranging device 222 for the pseudorange and the ranging device 221 for the slave transponder at the transponder end 220, the uplink and downlink signals between the satellite 100 and the transponder end 220 in the pseudorange downlink signal and the long transponder ranging signal pass through exactly the same atmospheric path, and the total number of electrons in the ionosphere experienced is exactly the same. The time difference for passing through the ionosphere is also very small, similar to that on the self-transmitting and self-receiving end 210 side. The pseudorange uplink signal or pseudorange downlink signal between the satellite and the transponder end also has the same spatial distance and tropospheric time delay relationship with the ranging signal for the slave transponder. Therefore, there are equations (u19), (u20):

[0155] R true,pd,1 (n) = R true,pd,2 (n) = R true,uu,1 (n) = R true,ud,1 (n)(u19);

[0156] T duiliu,pd,1(n) = T duiliu,pd,2 (n) = T duiliu,uu,1 (n) = T duiliu,ud,1 (n)(u20);

[0157] Before introducing the specific method, it should be particularly noted that in the long pseudorange ranging value formula (p1), the ±c·(δt u (n) - δt z (n)), when taking +c·(δt u (n) - δt z (n)), it corresponds to the long pseudorange ranging signal broadcast by the self - transmitting and self - receiving end 210, and the relay end 220 receives and measures the long pseudorange ranging signal; when taking -c·(δt u (n) - δt z (n)), it corresponds to the relay end 220 broadcasting the long pseudorange ranging signal, and the self - transmitting and self - receiving end 210 receives and measures the long pseudorange ranging signal;

[0158] Similarly, when it comes to the relative clock error ±c·(δt u (n) - δt z (n)) in the long pseudorange ranging value formula (p1), such as ±c·(δt u (n) - δt z (n)) in formulas (u5), (u9), etc. In the following specification, for the sake of convenience, +c·(δt u (n) - δt z (n)) is used in formulas (u5), (u9), etc. to represent.

[0159] Because the directions of the long pseudorange ranging signals are different, except that the signs of the relative clock errors between the self - transmitting and self - receiving end 210 and the relay end 220 are opposite, the other parameter terms are the same. Therefore, when the self - transmitting and self - receiving end 210 broadcasts the long pseudorange ranging signal and the relay end 220 receives and measures, the pseudorange ranging formula is the following formula (fp1); when the relay end 220 broadcasts the long pseudorange ranging signal and the self - transmitting and self - receiving end 210 receives and measures, the pseudorange ranging formula is the following formula (sp1):

[0160]

[0161] The corresponding corrected long pseudorange ranging value formulas are (fp1') and (sp1'):

[0162]

[0163]

[0164] The corresponding corrected average long pseudorange ranging value formulas are (fu5) and (su5):

[0165]

[0166] The following uses the example of the self - transmitting and self - receiving end 210 broadcasting a long pseudo - range ranging signal and the relay end 220 receiving and measuring the long pseudo - range ranging signal for calculation and explanation. That is, it is expanded using the long pseudo - range ranging formula (fp1) and the corrected long pseudo - range ranging formula (fp1') corresponding to the long pseudo - range ranging signal broadcast by the self - transmitting and self - receiving end 210, as well as the corrected average long pseudo - range ranging value formula (fu5).

[0167] Thus, based on the above - mentioned embodiments, for the first new type of high - precision relay - type satellite time - transfer system, the embodiments of the present application provide a satellite time - transfer method for this system. This satellite time - transfer method can be applied to the first new type of high - precision relay - type satellite time - transfer system described in any of the above - mentioned embodiments, and this satellite time - transfer method can be executed by a computing device.

[0168] The method for calculating the relative clock difference between the relay end and the self - transmitting and self - receiving end provided by the embodiments of the present application is for Figure 1 explanation. At this time, there are m = 1 long pseudo - range ranging values, h = 1 master relay ranging value, and r = 1 slave relay ranging value participating in the calculation.

[0169] Figure 6 It is a flowchart of a satellite time - transfer method according to an embodiment of the present application. As Figure 6 shown, this satellite time - transfer method may include the following steps:

[0170] S100. Obtain m long pseudo - range ranging values, h master relay ranging values, and r slave relay ranging values based on the communication results with the self - transmitting and self - receiving end and the relay end. Among them, the master relay ranging value is measured by the self - transmitting and self - receiving end for the master relay ranging signal, the slave relay ranging value is measured by the relay end for the slave relay ranging signal, the long pseudo - range ranging value is measured by the self - transmitting and self - receiving end or the relay end for the long pseudo - range ranging signal, and m, h, and r are all positive integers;

[0171] S110. Respectively use the long pseudo - range ranging expression to represent each of the long pseudo - range ranging values and use the relay ranging expression to represent each of the master relay ranging values and each of the slave relay ranging values;

[0172] S120. Determine the relative clock difference between the self - transmitting and self - receiving end and the relay end based on each of the long pseudo - range ranging values, each of the master relay ranging values, each of the slave relay ranging values, and the first preset carrier frequency relationship represented by the corresponding expressions.

[0173] In an exemplary embodiment, in step S110, the computing device can use the formula shown in formula (fp1) to express the pseudo - range ranging value numbered i:

[0174]

[0175] where \(i = 1, 2, \ldots, m\), and \(i\) and \(m\) are positive integers;

[0176] Specifically, the computing device obtains the first long pseudo - range ranging value shown in the following formula (fp1 - 1):

[0177]

[0178] The computing device can use the ranging value of the \(k\) - th slave - re - transmission shown in the following formula (u1):

[0179] L u,k (n)=R true,uu,k (n)+R true,ud,k (n)+I uu,k (n)+I ud,k (n)+T duiliu,uu,k (n)+T duiliu,ud,k (n)+Y u,k (n)(u1);

[0180] where \(k = 1, 2, \ldots, r\), and \(k\) and \(r\) are positive integers;

[0181] Specifically, the computing device obtains the first slave - re - transmission ranging value shown in the following formula (u1 - 1): L u,1 (n)=R true,uu,1 (n)+R true,ud,1 (n)+I uu,1 (n)+I ud,1 (n)+T duiliu,uu,1 (n)+T duiliu,ud,1 (n)+Y u,1 (n)(u1 - 1);

[0182] In addition, the computing device can use the ranging value of the \(j\) - th master - re - transmission shown in the following formula (z1):

[0183] L z,j (n)=R true,zu,j (n)+R true,zd,j (n)+I zu,j (n)+I zd,j (n)+T duiliu,zu,j (n)+T duiliu,zd,j (n)+Y z,j (n)(z1);

[0184] where \(j = 1, 2, \ldots, h\), and \(j\) and \(h\) are positive integers;

[0185] Specifically, the computing device obtains the first master - re - transmission ranging value shown in the following formula (z1 - 1): Lz,1 r(n) = R true,zu,1 r(n) + R true,zd,1 r(n) + I zu,1 r(n) + I zd,1 r(n) + T duiliu,zu,1 r(n) + T duiliu,zd,1 r(n) + Y z,1 r(n)(z1 - 1);

[0186] In some embodiments, step S120 may specifically include the following processes:

[0187] S121. Correct the m long pseudorange ranging values characterized by the pseudorange ranging expression to obtain m corrected long pseudorange ranging values, and perform an average calculation on the m corrected long pseudorange ranging values to obtain a corrected average long pseudorange ranging value;

[0188] S122. Correct the h master retransmission ranging values characterized by the retransmission ranging expression to obtain h corrected master retransmission ranging values, and perform an average calculation on the h corrected master retransmission ranging values to obtain h corrected average master retransmission ranging values;

[0189] S123. Correct the r slave retransmission ranging values characterized by the retransmission ranging expression to obtain r corrected slave retransmission ranging values, and perform an average calculation on the r corrected slave retransmission ranging values to obtain a corrected average slave retransmission ranging value;

[0190] S124. Determine the relative clock offset between the self - transmitting and receiving end and the retransmission end based on the corrected average long pseudorange ranging value, the corrected average slave retransmission ranging value, the corrected average master retransmission ranging value, and the first preset carrier frequency relationship.

[0191] Specifically, in step S121, the first long pseudorange ranging value shown in formula (fp1 - 1) obtained in the above step is corrected according to formula (fp1') to obtain the first corrected long pseudorange ranging value shown in formula (fp1' - 1):

[0192]

[0193] In step S122, the computing device corrects the first master retransmission ranging value shown in formula (z1 - 1) to obtain the first corrected master retransmission ranging value shown in formula (z1' - 1):

[0194]

[0195] In step S123, the computing device corrects the first slave retransmission ranging value shown in formula (u1 - 1) to obtain the first corrected slave retransmission ranging value shown in formula (u1' - 1):

[0196]

[0197] Average the m = 1 first corrected long pseudo-range ranging values shown in formula (fp1'-1) according to formula (fu5) to obtain the corrected average long pseudo-range ranging value shown in formula (fu5-1):

[0198]

[0199] Average the h = 1 first corrected master forward ranging values shown in formula (z1'-1) to obtain the first corrected average master forward ranging value shown in formula (u6-1):

[0200]

[0201] Average the r = 1 first corrected slave forward ranging values shown in formula (u1'-1) according to formula (u7) to obtain the corrected average slave forward ranging value shown in formula (u7-1):

[0202]

[0203] In step S124, the corrected average long pseudo-range ranging value shown in formula (fu5-1), the corrected average master forward ranging value shown in formula (u6-1), and the corrected average slave forward ranging value shown in formula (u7-1) obtained through the above steps, combined with the first preset carrier frequency relationship for further processing, can obtain the relative clock difference between the self-transmitting and receiving end and the forwarding end.

[0204] In an exemplary embodiment, step S124 may specifically include:

[0205] S1241. Perform mathematical processing on the corrected average long pseudo-range ranging value, the corrected average slave forward ranging value, and the corrected average master forward ranging value to obtain the clock difference expression of the self relative to the system time;

[0206] S1242. Use the clock difference expression to determine the clock difference of the self relative to the system time.

[0207] Among them, the computing device calculates the following result shown in formula (u9-1) by using the corrected average pseudo-range ranging value, the corrected average slave forward ranging value, and the corrected average master forward ranging value:

[0208]

[0209] Then, the computing device further uses the equations (z19), (z20), (u19), and (u20) obtained above and substitutes them into formula (u9-1) to obtain the clock difference of the self relative to the system time shown in formula (u9-2) as follows:

[0210]

[0211] As can be seen from formula (u9-2), after the above steps are processed, the tropospheric delay parameter term and the satellite-ground space distance term are eliminated from the obtained clock error, and the ionospheric delay combination term is still included at this time.

[0212] Because the carrier frequencies corresponding to the m long pseudorange ranging values, the carrier frequencies corresponding to the r retransmission ranging values, and the carrier frequencies corresponding to the h master retransmission ranging values satisfy the first preset carrier frequency relationship shown in formula (f1) as described above.

[0213]

[0214] The following part in formula (f1) is a linear combination of the squares of the carrier frequencies of the pseudorange uplink signal and the master retransmission ranging signal, as shown in formula (f1-z):

[0215]

[0216] When the long pseudorange ranging signal is transmitted by the retransmission end and received by the self-transmitting and self-receiving end, the subscript of the carrier frequency of the pseudorange downlink signal is still represented by pu,i, and the above formula (f1-z) still applies.

[0217] Multiply both sides of formula (f1-z) by Q ion ·TEC z (n) to obtain the ionospheric delay composition of the pseudorange uplink signal and the master retransmission ranging signal, and obtain formula (u30):

[0218]

[0219] The following part in formula (f1) is a linear combination of the squares of the carrier frequencies of the pseudorange downlink signal and the retransmission ranging signal, as shown in formula (f1-u):

[0220]

[0221] Multiply both sides of formula (f1-u) by Q ion ·TEC u (n) to obtain the ionospheric delay composition of the pseudorange downlink signal and the retransmission ranging signal, and obtain formula (u31):

[0222]

[0223] Because the total ionospheric electron number TEC z (n) between the satellite and the self-transmitting and self-receiving end is unknown, and the total ionospheric electron number TEC u(n) is also an unknown number. Therefore, the sum of the ionospheric delay combination results shown in formulas (u30) and (u31) is also an unknown number. Combining with formula (f1), this sum result is a numerical range and also an unknown number. Taking this unknown number as the error of the relative clock difference between the self-transmitting and receiving end and the forwarding end, thus according to formula (u9-2), the result shown in formula (u9) is obtained:

[0224]

[0225] When applied to this embodiment, there is only one long pseudo-range ranging signal, one main forwarding ranging signal, and one slave forwarding ranging signal. The relative clock difference between the self-transmitting and receiving end and the forwarding end obtained is still (u9), and the reason is also as shown above, except that at this time m = 1, h = 1, r = 1.

[0226] In some embodiments, after step S110, the satellite time synchronization method may further include the following steps: using the pseudo-range smoothing algorithm to correct the slave forwarding ranging value, the main forwarding ranging value, and the long pseudo-range ranging value. Correspondingly, in step S120, the relative clock difference between the self-transmitting and receiving end and the forwarding end can be calculated using the slave forwarding ranging value, the main forwarding ranging value, and the long pseudo-range ranging value corrected by the pseudo-range smoothing algorithm. It can be understood that using the pseudo-range smoothing algorithm to correct the long pseudo-range ranging value, the main forwarding ranging value, and the slave forwarding ranging value can reduce the noise of the pseudo-range ranging value and the slave forwarding ranging value, which is beneficial to improving the accuracy of the finally determined clock difference. The specific content of the pseudo-range smoothing algorithm will not be elaborated here.

[0227] For the carrier frequency relationship shown in formula (f1-z), when it evolves into the following special form, as shown in formula (f1-z-1):

[0228]

[0229] Multiply both sides of formula (f1-z-1) by Q ion ·TEC z (n), the obtained result is still 0. At this time, it indicates that the linear combination result of the ionospheric delay of the pseudo-range uplink signal and the ionospheric delay of the main forwarding ranging signal is 0, completely eliminating the influence of the ionospheric delay error.

[0230] For the carrier frequency relationship shown in formula (f1-u), when it evolves into the following special form, as shown in formula (f1-u-1):

[0231]

[0232] Multiply both sides of formula (f1-u-1) by Q ion ·TEC u(n), the resulting value is still 0, which indicates that the linear combination of the ionospheric delay of the pseudorange downlink signal and the ionospheric delay of the transponder ranging signal is 0, completely eliminating the influence of the ionospheric delay error.

[0233] If the carrier frequencies of the long pseudorange ranging signal, the carrier of the main transponder ranging signal, and the carrier frequency of the slave transponder ranging signal simultaneously satisfy the conditions of formula (f1-z-1) and formula (f1-u-1), the relative clock difference between the self-transmitting and receiving end and the transponder end obtained is completely free of the ionospheric delay error, and the accuracy of the obtained clock difference is greatly improved, making it very valuable at this time.

[0234] In addition to the above situation, the present application provides another special case. When the long pseudorange ranging signal broadcast by the self-transmitting and receiving end reaches the satellite, it is split into two parts. One part is used as the long pseudorange ranging signal and measured by the transponder end to obtain the long pseudorange ranging value, and the other part is used as the main downlink signal and forwarded back to the self-transmitting and receiving end to obtain the main transponder ranging value. At this time, there is a carrier frequency relationship: f pu,1 (n) = f zu,1 (n) ≠ f zd,1 (n); similarly, when the slave uplink signal broadcast by the transponder end reaches the satellite, the carrier frequencies of the slave downlink signal and the pseudorange downlink signal after satellite transponder are the same, and carrier frequency multiplexing is performed to obtain the slave transponder ranging value. At this time, there is a carrier frequency relationship: f pd,1 (n) = f ud,1 (n) ≠ f uu,1 (n),

[0235] At this time, it is still necessary to satisfy the first preset carrier frequency relationship, specifically formula (f1-2):

[0236]

[0237] The relative clock difference between the self-transmitting and receiving end and the transponder end obtained at this time is:

[0238]

[0239] Regarding as an error, the clock difference of the transponder end obtained is still the result shown in formula (u9).

[0240] At this time, the purpose of time service can be achieved by using fewer carrier frequency resources.

[0241] Thus, on the basis of the above embodiments, for the second new type of high-precision transponder satellite time service system, the embodiments of the present application provide a satellite time service method for this system. This satellite time service method can be applied to the second new type of high-precision transponder satellite time service system described in any of the above embodiments, and this satellite time service method can be executed by a computing device. Figure 7Flowchart of a satellite time synchronization method according to another embodiment of the present application, as shown in Figure 7 shown, the satellite time synchronization method may include the following steps:

[0242] S200. Obtain s long forward ranging values and m long pseudorange ranging values based on the communication results with the self-transmitting and receiving end and the forwarding end. Among them, the long forward ranging values are measured by the self-transmitting and receiving end for the long forward ranging signal, and the long pseudorange ranging values are measured by the self-transmitting and receiving end or the forwarding end for the long pseudorange ranging signal. Both s and m are positive integers;

[0243] S210. Use the long pseudorange ranging expression to characterize the long pseudorange ranging values respectively and use the long forward ranging expression to characterize the long forward ranging values;

[0244] S220. Determine the relative clock difference between the self-transmitting and receiving end and the forwarding end based on each of the long pseudorange ranging values, each of the long forward ranging values characterized by the corresponding expressions, and the second preset carrier frequency relationship.

[0245] Among them, in step S220, the computing device can obtain, through data transmission, the satellite forwarding delay, the pseudorange uplink signal transmission delay, and the transmission, reception, or forwarding delay of the main forwarding ranging device.

[0246] Similarly, when it comes to the relative clock difference ±c·(δt u (n)-δt z (n)) in the long pseudorange ranging value formula (p1), such as ±c·(δt u (n)-δt z (n)) in formulas (u5), (u10), etc. In the following description, for the sake of convenience, +c·(δt u (n)-δt z (n)) is used to represent in formulas (u5), (u10), etc.

[0247] In step S210, in Figure 2 the working mode, the self-transmitting and receiving end obtains the long forward ranging value in the form of self-transmitting and receiving;

[0248] The computing device can use the formula shown in (fp1) to characterize the long pseudorange ranging value numbered i:

[0249]

[0250] where i = 1, 2,..., m, and both i and m are positive integers;

[0251] Specifically, the obtained first long pseudorange ranging value can be characterized by the formula (fp1-1):

[0252]

[0253] The long forward ranging value is characterized by the formula shown in (u2) as the long forward ranging value numbered e:

[0254]

[0255] where e = 1, 2, ……, s, and e and s are positive integers;

[0256] Specifically, the first long forward ranging value can be characterized by the formula (u2-1):

[0257]

[0258] In some embodiments, step S220 may specifically include the following process:

[0259] S221. Correct the m long pseudorange ranging values characterized by the long pseudorange ranging expression to obtain m corrected long pseudorange ranging values, and perform an average calculation on the m corrected long pseudorange ranging values to obtain a corrected average long pseudorange ranging value;

[0260] S222. Correct the s long forward ranging values characterized by the long forward ranging expression to obtain s corrected long forward ranging values, and perform an average calculation on the s corrected long forward ranging values to obtain a corrected average long forward ranging value;

[0261] S223. Determine the relative clock offset between the self-transmitting and receiving end and the forwarding end based on the corrected average long pseudorange ranging value, the corrected average long forward ranging value, and the second preset carrier frequency relationship.

[0262] Specifically, step S221 is to correct the first long pseudorange ranging value expression shown in the formula (fp1-1) obtained in the above step according to the formula (fp1') to obtain the first corrected long pseudorange ranging value shown in the formula (fp1'-1):

[0263]

[0264] In step S222, the computing device corrects the first long forward ranging value represented by the following formula (u2-1) according to the formula (u2') to obtain the first long corrected long forward ranging value shown in the formula (u2'-1):

[0265]

[0266] Average the m = 1 first corrected long pseudorange ranging values shown in formula (p1'-1) according to formula (fu5) to obtain the corrected average long pseudorange ranging value shown in formula (u5-1):

[0267]

[0268] Average the s = 1 first corrected long retransmission ranging values shown in formula (u2'-1) according to (u8) to obtain the corrected average long retransmission ranging value shown in formula (u8-1):

[0269]

[0270] In step S223, the corrected average long pseudorange ranging value shown in formula (fu5-1) and the corrected average long retransmission ranging value shown in formula (u8-1) obtained through the above steps are further processed to obtain the relative clock offset between the self-transmitting and receiving end and the retransmission end.

[0271] In an exemplary embodiment, step S223 may specifically include:

[0272] S2231. Perform mathematical processing on the corrected average long pseudorange ranging value and the corrected average long retransmission ranging value to obtain the relative clock offset expression between the self-transmitting and receiving end and the retransmission end;

[0273] S2232. Use the clock offset expression to determine the relative clock offset between the self-transmitting and receiving end and the retransmission end.

[0274] Among them, the computing device calculates the corrected average long pseudorange ranging value and the corrected average long retransmission ranging value to obtain the relative clock offset expression between the self-transmitting and receiving end and the retransmission end shown in the following formula (u10-1):

[0275]

[0276] Then, the retransmission end further uses the equalities (z19), (z20), (u19), and (u20) obtained above and substitutes them into formula (u10-1) to obtain the relative clock offset between the self-transmitting and receiving end and the retransmission end shown in the following formula (u10-2):

[0277]

[0278] It can be seen from formula (u10-2) that after the above steps of processing, the tropospheric delay parameter term and the space distance term between the satellite and the ground in the obtained clock offset are eliminated, and the ionospheric delay combination term is still included.

[0279] Because the carrier frequencies corresponding to the m long pseudorange ranging values and the carrier frequencies corresponding to the s long transponder ranging values satisfy the second preset carrier frequency relationship shown in formula (f2).

[0280] The following part in formula (f2) is a linear combination of the squares of the carrier frequencies of the signals between the satellite and the self-transmitting and self-receiving end in the pseudorange uplink signal and the long transponder ranging signal, as shown in formula (f2-z):

[0281]

[0282] When the long pseudorange ranging signal is transmitted by the transponder and received by the self-transmitting and self-receiving end, the subscript of the carrier frequency of the pseudorange downlink signal is still represented by pu,i, and the above formula (f2-z) still applies.

[0283] Multiply both sides of formula (f2-z) by Q ion ·TEC z (n) to obtain the ionospheric delay composition of the signals between the satellite and the self-transmitting and self-receiving end in the pseudorange uplink signal and the long transponder ranging signal, and obtain formula (u32).

[0284]

[0285] The following part in formula (f2) is a linear combination of the squares of the carrier frequencies of the signals between the satellite and the transponder in the pseudorange downlink signal and the long transponder ranging signal, as shown in formula (f2-u):

[0286]

[0287] Multiply both sides of formula (f2-u) by Q ion ·TEC u (n) to obtain the ionospheric delay composition of the signals between the satellite and the transponder in the pseudorange downlink signal and the long transponder ranging signal, and obtain formula (u33).

[0288]

[0289] Because the total electron content TEC z (n) between the satellite and the self-transmitting and self-receiving end is an unknown, and the total electron content TEC u (n) between the satellite and the transponder is also an unknown, so the sum of the ionospheric delay combination results shown in formula (u32) and (u33) is also an unknown. Combining with formula (f2), this sum result is a numerical range and is also an unknown. Taking this unknown as the error of the clock offset of the transponder relative to time, the result shown in formula (u10) is obtained:

[0290]

[0291] When applied to this embodiment, there is only one long pseudo-range ranging signal and one long retransmitted ranging signal. The relative clock difference between the self-transmitting / receiving end and the retransmitting end obtained is still (u10), and the reason is as shown above, except that at this time m = 1 and h = 1.

[0292] For the carrier frequency relationship shown in formula (f2-z), when it evolves into the following special form, as shown in formula (f2-z-1):

[0293]

[0294] Multiply both sides of formula (f2-z-1) by Q ion ·TEC z (n), the resulting result is still 0. At this time, it indicates that the linear combination result of the ionospheric delay of the pseudo-range uplink signal and the ionospheric delay of the signal between the satellite and the self-transmitting / receiving end in the retransmitted ranging signal is 0, completely eliminating the influence of the ionospheric delay error.

[0295] For the preset carrier frequency relationship shown in formula (f2-u), when it evolves into the following special form, as shown in formula (f2-u-1):

[0296]

[0297] Multiply both sides of formula (f2-u-1) by Q ion ·TEC u (n), the resulting result is still 0. At this time, it indicates that the linear combination result of the ionospheric delay of the pseudo-range downlink signal and the ionospheric delay of the signal between the satellite and the retransmitting end in the retransmitted ranging signal is 0, completely eliminating the influence of the ionospheric delay error.

[0298] If the carrier frequency of the long pseudo-range ranging signal and the carrier of the long retransmitted ranging signal simultaneously satisfy the conditions of formula (f2-z-1) and formula (f2-u-1), then the relative clock difference between the self-transmitting / receiving end and the retransmitting end obtained completely eliminates the ionospheric delay error, and the accuracy of the obtained clock difference is greatly improved, and it becomes very valuable at this time.

[0299] In addition to the above situation, this application provides another special situation. When the long pseudo-range ranging signal broadcast by the self-transmitting / receiving end reaches the retransmitting end, it is split into two parts. One part is used as the long pseudo-range ranging signal and the retransmitting end measures the long pseudo-range ranging value, and the other part is used as the long retransmitted ranging signal and is retransmitted back to the self-transmitting / receiving end to obtain the long retransmitted ranging value. At this time, there is a carrier frequency relationship:

[0300] f pu,1 (n) = f zu,1 (n) ≠ f zd,1 (n), f pd,1(n) = f ud,1 (n) ≠ f uu,1 (n)

[0301] At this time, it is still necessary to satisfy the second preset carrier frequency relationship, specifically the formula (f2 - 2):

[0302]

[0303] At this time, the relative clock difference between the self - transmitting and self - receiving end and the forwarding end is:

[0304]

[0305] Taking as an error, the clock difference of the forwarding end is the result shown in the formula (u10).

[0306] At this time, the time - service purpose can be achieved by using fewer carrier frequency resources.

[0307] When the long pseudo - range ranging signal broadcast by the self - transmitting and self - receiving end reaches the forwarding end, the long pseudo - range ranging signal is measured by the forwarding end to obtain the long pseudo - range ranging value; the forwarding end broadcasts a long forwarding ranging signal. The carrier frequencies of the main uplink signal forwarded by the self - transmitting and self - receiving end and the long pseudo - range uplink signal are multiplexed, and the carrier frequencies of the downlink signal from the satellite after forwarding and the pseudo - range downlink signal are multiplexed. There is still the above - mentioned carrier frequency relationship, and the clock difference result of the forwarding end is the same.

[0308] In some embodiments, after step S210, the satellite time - service method may further include the following steps: using a pseudo - range smoothing algorithm to correct the long forwarding ranging value and the long pseudo - range ranging value. Correspondingly, in step S220, the long forwarding ranging value and the long pseudo - range ranging value corrected by the pseudo - range smoothing algorithm can be used to calculate the clock difference of the device relative to the system time. It can be understood that using the pseudo - range smoothing algorithm to correct the long pseudo - range ranging value and the long forwarding ranging value can reduce the noise of the long pseudo - range ranging value and the long forwarding ranging value, which is beneficial to improving the accuracy of the finally determined clock difference. The specific content of the pseudo - range smoothing algorithm will not be elaborated here.

[0309] In addition to the above embodiments, the present application also provides the following embodiments.

[0310] Figure 3 For a schematic structural diagram of another new high - precision forwarding - type satellite time - service system provided by the embodiments of the present application, as Figure 3 shown, there are m = 2 long pseudo - range ranging signals between the self - transmitting and self - receiving end, the satellite, and the forwarding end. There is one main forwarding ranging signal between the self - transmitting and self - receiving end and the satellite, and one slave forwarding ranging signal between the forwarding end and the satellite. When Figure 3When the signals in satisfy the first preset carrier frequency relationship, the method of the present application can still be used to obtain the relative clock difference between the self-transmitting and receiving end and the forwarding end. At this time, the value of V is taken as 0, m = 2, h = 1, r = 1, and the formula (f1) is specifically:

[0311]

[0312] Let the carrier frequencies of the signals between the self-transmitting and receiving end and the satellite, and between the forwarding end and the satellite satisfy respectively:

[0313]

[0314] If both sides of the formula (f1-6) are multiplied by Q ion ·TEC z (n), the ionospheric delay combination of the pseudorange uplink signal and the main forwarding ranging signal is 0; if both sides of the formula (f1-6) are multiplied by Q ion ·TEC u (n), the ionospheric delay combination of the pseudorange downlink signal and the slave forwarding ranging signal is 0.

[0315] In this way, the accurate relative clock difference between the self-transmitting and receiving end and the forwarding end is obtained according to the present application.

[0316] Similarly, when Figure 3 the main forwarding ranging signal and the slave forwarding ranging signal in the embodiment shown in become a long forwarding ranging signal, there are m = 2 long pseudorange ranging signals between the self-transmitting and receiving end, the satellite, and the forwarding end, and there is one long forwarding ranging signal between the self-transmitting and receiving end and the forwarding end. When the signals satisfy the second preset carrier frequency relationship at this time, the method of the present application can still be used to obtain the relative clock difference between the self-transmitting and receiving end and the forwarding end. At this time, the value of V is taken as 0, m = 2, s = 1, and the formula (f2) is specifically:

[0317]

[0318] Let the carrier frequencies of the signals between the self-transmitting and receiving end and the satellite, and between the forwarding end and the satellite satisfy respectively:

[0319]

[0320] If both sides of the formula (f2-6) are multiplied by Q ion ·TEC z (n), the ionospheric delay combination of the pseudorange uplink signal and the signal between the self-transmitting and receiving end and the satellite in the long forwarding ranging signal is 0; if both sides of the formula (f2-6) are multiplied by Q ion ·TEC u(n), the combined ionospheric time delay of the signals between the transponder and the satellite in the pseudorange downlink signal and the long transponder ranging signal is obtained as 0.

[0321] In this way, an accurate relative clock difference between the self-transmitting and self-receiving end and the transponder can be obtained according to the present application.

[0322] Other situations will not be exemplified one by one.

[0323] After obtaining the value of c·(δt u (n) - δt z (n)) using the above two methods, dividing it by the speed of light c can obtain the relative clock difference (δt u (n) - δt z (n)) between the self-transmitting and self-receiving end and the transponder.

[0324] Among them, after calculating the relative clock difference between the self-transmitting and self-receiving end and the transponder, when the clock difference δt z of the self-transmitting and self-receiving end relative to the system time is a known quantity, the clock difference δt u of the transponder relative to the system time can be easily obtained; conversely, when the clock difference δt u of the transponder relative to the system time is a known quantity, the clock difference δt z of the self-transmitting and self-receiving end relative to the system time can be easily obtained;

[0325] In the embodiments of the present application, the self-transmitting and self-receiving end can be the main operation and control station, and the transponder can be the user station; or, the self-transmitting and self-receiving end can be the user station, and the transponder can be the main operation and control station.

[0326] When the time of the main operation and control station is the standard time or UTC time, the long pseudorange ranging signal broadcast by the main operation and control station is to transmit the standard time outward, which is generally called time service. At this time, δt z (n) is the known quantity Δt, and the clock difference between the user station and the main operation and control station is obtained. When using time service, the clock difference δt z (n) of the main operation and control station relative to the system is generally zero. At this time, Δt = 0, so there is an equation (z18):

[0327] δt z (n) = Δt = 0 (z18);

[0328] When Δt is not equal to 0, the relative clock difference between the main operation and control station and the user station can still be calculated according to the method of the present application.

[0329] Based on the above embodiments, the embodiments of the present application further provide an inter-station time synchronization system. The inter-station time synchronization system may include the inter-station time synchronization system described in any of the above embodiments, and the transponder or the self-transmitting and self-receiving end is the user station;

[0330] Wherein, when there are multiple user stations, the multiple user stations respectively exchange data with a computing device to achieve time synchronization among the multiple user stations.

[0331] In summary, compared with the existing RDSS system and CAPS system, the system and related methods provided by the embodiments of the present application creatively utilize the relationship between carrier frequencies to partially or completely overcome the ionospheric delay, and propose a new type of high-precision transponder satellite timing system. The system has at least the following advantages:

[0332] 1. The method of the embodiment of the present application completely eliminates the influence brought by the ionosphere by using the relationship between carrier frequencies, does not rely on ionospheric data provided by a third party, and improves the security and controllability of the system.

[0333] 2. The satellite timing method provided by the embodiment of the present application has low requirements for the coordinate accuracy of satellites, self-transmitting and self-receiving ends, and transponders. It is not necessary to have accurate satellite coordinates, self-transmitting and self-receiving end coordinates, and transponder coordinates to correct the Sagnac effect, and then achieve high-precision timing.

[0334] 3. For satellites, the satellites only need the transponders to forward signals according to the relationship of carrier frequencies to achieve the system functions, which can reduce the complexity of satellite payloads and the cost of satellites.

[0335] 4. Compared with the current RDSS system and CAPS system, upgrading the RDSS system or CAPS system according to the method provided by the present application can bring new vitality to the two existing systems.

[0336] The above are only the preferred embodiments of the present application, and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made by using the content of the specification and drawings of the present application, or directly or indirectly applied to other related technical fields, shall be equally included in the patent protection scope of the present application.

Claims

1. A novel high-precision retransmission satellite timekeeping system, characterized in that, The system includes a satellite, a self-transmitting and self-receiving terminal, and a forwarding terminal. The self-transmitting and self-receiving terminal and the forwarding terminal are both communicatively connected to the satellite; There are m long pseudo-range ranging signals between the self-transmitting and self-receiving terminal, the satellite, and the forwarding terminal. There are h main forwarding ranging signals between the satellite and the self-transmitting and self-receiving terminal, and r slave forwarding ranging signals between the satellite and the forwarding terminal. Among them, the carrier frequencies of the m long pseudo-range ranging signals, the carrier frequencies of the h main forwarding ranging signals, and the carrier frequencies of the r slave forwarding ranging signals satisfy a first preset carrier frequency relationship. The signals between the self-transmitting and self-receiving terminal and the satellite, and the signals between the forwarding terminal and the satellite each have at least two different carrier frequencies. m, h, and r are all positive integers greater than or equal to 1; Or, There are m long pseudo-range ranging signals and s long forwarding ranging signals between the self-transmitting and self-receiving terminal, the satellite, and the forwarding terminal. Among them, the carrier frequencies of the m long pseudo-range ranging signals and the carrier frequencies of the s long forwarding ranging signals satisfy a second preset carrier frequency relationship. The signals between the self-transmitting and self-receiving terminal and the satellite, and the signals between the forwarding terminal and the satellite each have at least two different carrier frequencies. m and s are both positive integers greater than or equal to 1; Among them, the long pseudo-range ranging signal is composed of a pseudo-range uplink signal and a pseudo-range downlink signal. The pseudo-range uplink signal is broadcast by the self-transmitting and self-receiving terminal or the forwarding terminal. The satellite forwards the pseudo-range uplink signal into the pseudo-range downlink signal, and the forwarding terminal or the self-transmitting and self-receiving terminal receives the pseudo-range downlink signal; The long forwarding ranging signal is composed of a first uplink signal broadcast by the self-transmitting and self-receiving terminal, a first downlink signal received and forwarded by the satellite from the first uplink signal, a second uplink signal received and forwarded by the forwarding terminal from the first downlink signal, and a second downlink signal received by the satellite from the second uplink signal and forwarded to the self-transmitting and self-receiving terminal; The main forwarding ranging signal is composed of a main uplink signal and a main downlink signal. The self-transmitting and self-receiving terminal broadcasts the main uplink signal and receives the main downlink signal. The satellite receives the main uplink signal and forwards it to form the main downlink signal; The slave forwarding ranging signal is composed of a slave uplink signal and a slave downlink signal. The forwarding terminal broadcasts the slave uplink signal and receives the slave downlink signal. The satellite receives the slave uplink signal and forwards it to form the slave downlink signal.

2. The novel high-precision forwarding satellite time service system according to claim 1, wherein The long pseudo-range ranging signal, the long forwarding ranging signal, the main forwarding ranging signal, and the slave forwarding ranging signal are all spread spectrum signals. Spread spectrum technology, carrier frequency reuse, and code division multiple access technology are used for corresponding processing during signal transmission, forwarding, and reception processing.

3. The novel high-precision forwarding satellite time service system according to claim 1, wherein The carrier frequencies of the m long pseudo-range ranging signals, the carrier frequencies of the h main forwarding ranging signals, and the carrier frequencies of the r slave forwarding ranging signals satisfy the first preset carrier frequency relationship shown in formula (f1): The carrier frequency of the m-channel long pseudo-range ranging signal and the carrier frequency of the s-channel long re-transmission ranging signal satisfy the second preset carrier frequency relationship shown in formula (f2): Wherein, the value of V is equal to 1e-12; Where: m represents the number of long pseudo-range ranging signals; i represents the number of the long pseudo-range ranging signal; h represents the number of master transponder ranging signals; j represents the number of the master transponder ranging signal; r represents the number of slave transponder ranging signals; k represents the number of the slave transponder ranging signal; s represents the number of long transponder ranging signals; e represents the number of the long transponder ranging signal; f pu,i (n) represents the carrier frequency of the pseudo-range downlink signal or pseudo-range uplink signal between the satellite and the self-transmitting and self-receiving end in the long pseudo-range ranging signal numbered i at the nth moment, unit: Hertz; f pd,i (n) represents the carrier frequency of the pseudo-range downlink signal or pseudo-range uplink signal between the satellite and the transponder end in the long pseudo-range ranging signal numbered i at the nth moment, unit: Hertz; f zu,j (n), f zd,j (n) represents the carrier frequency of the main uplink signal and main downlink signal of the master transponder ranging signal numbered j at the nth moment, unit: Hertz; f uu,k (n), f ud,k (n) represents the carrier frequency of the slave uplink signal and slave downlink signal of the slave transponder ranging signal numbered k at the nth moment, unit: Hertz; f zu,e (n), f zd,e (n) represents the carrier frequency of the first uplink signal and second downlink signal between the self-transmitting and self-receiving end and the satellite in the long transponder ranging signal numbered e at the nth moment, unit: Hertz; f uu,e (n), f ud,e (n) represents the carrier frequency of the first downlink signal and second uplink signal between the transponder end and the satellite in the long transponder ranging signal numbered e at the nth moment, unit: Hertz.

4. The novel high-precision forwarding satellite time service system according to claim 1, characterized in that The carrier frequency of the long pseudo-range ranging signal, the carrier frequency of the master re-transmission ranging signal, and the carrier frequency of the slave re-transmission ranging signal perform frequency hopping on the time axis according to a preset frequency hopping pattern and satisfy the first preset carrier frequency relationship; Alternatively, the carrier frequency of the long pseudo-range ranging signal and the carrier frequency of the long re-transmission ranging signal perform frequency hopping on the time axis according to a preset frequency hopping pattern and satisfy the second preset carrier frequency relationship.

5. The novel high-precision re-transmission satellite time service system according to claim 1, wherein The satellite includes: A transponder that forwards the received pseudo-range uplink signal into a pseudo-range downlink signal, forwards the received master uplink signal into a master downlink signal, forwards the received slave uplink signal into a slave downlink signal, forwards the first uplink signal into a first downlink signal, and forwards the second uplink signal into a second downlink signal; A satellite time-frequency device that provides time-frequency signals for the transponder; The self-transmitting and self-receiving end includes: A master re-transmission ranging device for transmitting the first uplink signal, receiving and measuring the second downlink signal to obtain a long re-transmission ranging value; A master pseudo-range ranging device for receiving the pseudo-range downlink signal and measuring to obtain a long pseudo-range ranging value or transmitting the pseudo-range uplink signal; A master time-frequency device for providing time-frequency signals to the master re-transmission ranging device and the master pseudo-range ranging device; The re-transmission end includes: A slave re-transmission ranging device for receiving the first downlink signal and forwarding it into the second uplink signal; A slave pseudo-range ranging device for receiving the pseudo-range downlink signal and measuring to obtain a long pseudo-range ranging value or transmitting the pseudo-range uplink signal; A slave time-frequency device for providing time-frequency signals to the slave pseudo-range ranging device and the slave re-transmission ranging device; Or, The self-transmitting and self-receiving end includes: A master re-transmission ranging device for transmitting the master uplink signal, receiving and measuring the master downlink signal to obtain a master re-transmission ranging value; A master pseudo-range ranging device for receiving the pseudo-range downlink signal and measuring to obtain a long pseudo-range ranging value or transmitting the pseudo-range uplink signal; A master time-frequency device for providing time-frequency signals to the master re-transmission ranging device and the master pseudo-range ranging device; The re-transmission end includes: A slave re-transmission ranging device for transmitting the slave uplink signal and receiving the slave downlink signal to obtain a slave re-transmission ranging value; A slave pseudo-range ranging device for receiving the pseudo-range downlink signal and measuring to obtain a long pseudo-range ranging value or transmitting the pseudo-range uplink signal; A slave time-frequency device for providing time-frequency signals to the slave re-transmission ranging device and the slave pseudo-range ranging device.

6. The novel high-precision forwarding satellite time service system according to claim 5, wherein The master pseudo-range ranging device and the master re-transmission ranging device are set with zero baseline, and the slave pseudo-range ranging device and the slave re-transmission ranging device are set with zero baseline.

7. The novel high-precision forwarding satellite time service system according to claim 5, wherein, The self-transmitting and self-receiving end uses at least one master time-frequency device, and the re-transmission end uses at least one slave time-frequency device.

8. The novel high-precision forwarding satellite time service system according to claim 1, wherein The satellite uses an additional communication signal to perform data transmission with the self-transmitting and self-receiving end.

9. The novel high-precision transponder satellite time synchronization system according to claim 1, wherein the novel high-precision transponder satellite time synchronization system further comprises: A computing device communicatively connected to the self-transmitting and self-receiving end and the transponder respectively; Wherein, the computing device receives long pseudo-range ranging values, main transponder ranging values and slave transponder ranging values, and determines the relative clock difference between the self-transmitting and self-receiving end and the transponder based on the long pseudo-range ranging values, the main transponder ranging values, the slave transponder ranging values and a first preset carrier frequency relationship; the long pseudo-range ranging values are obtained by the self-transmitting and self-receiving end or the transponder measuring the long pseudo-range ranging signal, the main transponder ranging values are obtained by the self-transmitting and self-receiving end measuring the main transponder ranging signal, the slave transponder ranging signal is obtained by the transponder measuring the slave transponder ranging signal, and the number of the long pseudo-range ranging values, the main transponder ranging values and the slave transponder ranging values is at least 1; Or, The computing device receives long pseudo-range ranging values and long transponder ranging values, and determines the relative clock difference between the self-transmitting and self-receiving end and the transponder based on the long pseudo-range ranging values, the long transponder ranging values and a second preset carrier frequency relationship; the long transponder ranging values are obtained by the self-transmitting and self-receiving end measuring the long transponder ranging signal, the long pseudo-range ranging values are obtained by the self-transmitting and self-receiving end or the transponder measuring the long pseudo-range ranging signal, and the number of the long transponder ranging values and the long pseudo-range ranging values is at least 1.

10. An inter-station time synchronization system, characterized in that, Comprising: The novel high-precision transponder satellite time synchronization system according to any one of claims 1-9, wherein the transponder or the self-transmitting and self-receiving end is a user station; Wherein, when there are multiple user stations, the multiple user stations respectively perform data exchange with the computing device to achieve time synchronization between the multiple user stations.

11. A novel high-precision retransmission satellite time synchronization method, characterized in that, Applied to the novel high-precision transponder satellite time synchronization system according to any one of claims 1-9, the method is executed by a computing device, and the method comprises: Obtaining m long pseudo-range ranging values, h main transponder ranging values and r slave transponder ranging values based on the communication results with the self-transmitting and self-receiving end and the transponder, wherein the main transponder ranging values are obtained by the self-transmitting and self-receiving end measuring the main transponder ranging signal, the slave transponder ranging values are obtained by the transponder measuring the slave transponder ranging signal, the long pseudo-range ranging values are obtained by the self-transmitting and self-receiving end or the transponder measuring the long pseudo-range ranging signal, and m, h, r are all positive integers; Respectively using long pseudo-range ranging expressions to characterize each of the long pseudo-range ranging values and using transponder ranging expressions to characterize each of the main transponder ranging values and each of the slave transponder ranging values; Determining the relative clock difference between the self-transmitting and self-receiving end and the transponder based on each of the long pseudo-range ranging values, each of the main transponder ranging values, each of the slave transponder ranging values characterized by the corresponding expressions and the first preset carrier frequency relationship.

12. The method according to claim 11, wherein The step of respectively using long pseudo-range ranging expressions to characterize each of the long pseudo-range ranging values and using transponder ranging expressions to characterize each of the main transponder ranging values and each of the slave transponder ranging values includes: Characterize each of the long pseudo-range ranging values using the long pseudo-range ranging expression shown in the following formula (p1): where i = 1, 2, ……, m, and i and m are positive integers; Characterize each of the master relay ranging values using the relay ranging expression shown in the following formula (z1): L z,j (n) = R true,zu,j (n) + R true,zd,j (n) + I zu,j (n) + I zd,j (n) + T duiliu,zu,j (n) + T duiliu,zd,j (n) + Y z,j (n)(z1); where j = 1, 2, ……, h, and j and h are positive integers; Characterize each of the slave relay ranging values using the relay ranging expression shown in the following formula (u1): L u,k (n) = R true,uu,k (n) + R true,ud,k (n) + I uu,k (n) + I ud,k (n) + T duiliu,uu,k (n) + T duiliu,ud,k (n) + Y u,k (n)(u1); where k = 1, 2, ……, r, and k and r are positive integers; where: ρ p,i (n) represents the long pseudorange ranging value numbered i at the nth moment, unit: meter; R true,pu,i (n), R true,pd,i (n) represents the actual space distance passed by the pseudorange uplink signal and / or the pseudorange downlink signal of the long pseudorange ranging signal numbered i at the nth moment, unit: meter; I pu,i (n), I pd,i (n) represents the ionospheric delay of the pseudorange uplink signal and / or the pseudorange downlink signal of the long pseudorange ranging signal numbered i at the nth moment, unit: meter; T duiliu,pu,i (n), T duiliu,pd,i (n) represents the tropospheric delay of the pseudorange uplink signal and / or the pseudorange downlink signal of the long pseudorange ranging signal numbered i at the nth moment, unit: meter; c represents the speed of light, unit: meter per second; δt z (n) represents the clock error of the spontaneous self-receiving end relative to the system time at the nth moment, unit: second; δt u (n) represents the clock error of the transponder relative to the system time at the nth moment, unit: second; sagnac zz (n) represents the Sagnac effect delay of the pseudorange uplink signal at the nth moment, unit: meter; sagnac uu (n) represents the Sagnac effect delay of the pseudorange downlink signal at the nth moment, unit: meter; X p,i (n) represents the hardware device delay of the long pseudorange ranging signal numbered i at the nth moment, unit: meter. The hardware device delay of the long pseudorange ranging signal includes the transmission delay of the pseudorange uplink signal of the long pseudorange ranging signal numbered i, the forwarding delay of the satellite for forwarding the pseudorange uplink signal of the long pseudorange ranging signal numbered i to form the pseudorange downlink signal of the long pseudorange ranging signal numbered i, and the reception delay of the pseudorange downlink signal of the long pseudorange ranging signal numbered i; L z,j (n) represents the main forward ranging value of the j-th at the n-th moment, unit: meter; R true,zu,j (n), R true,zd,j (n) represents the actual space distance passed by the main uplink signal and the main downlink signal in the main forward ranging signal of the j-th at the n-th moment, unit: meter; I zu,j (n), I zd,j (n) represents the ionospheric delay of the main uplink signal and the main downlink signal in the main forward ranging signal of the j-th at the n-th moment, unit: meter; T duiliu,zu,j (n), T duiliu,zd,j (n) represents the tropospheric delay of the main uplink signal and the main downlink signal in the main forward ranging signal of the j-th at the n-th moment, unit: meter; Y z,j (n) represents the hardware device delay of the main forward ranging signal of the j-th at the n-th moment, unit: meter. The hardware device delay of the main forward ranging signal includes the transmission delay of the main uplink signal of the j-th, the forwarding delay of the main downlink signal generated by the satellite of the j-th, and the reception delay of the main downlink signal of the j-th; L u,k (n) represents the ranging value of the k-th slave retransmission at the n-th moment, unit: meter; R true,uu,k (n), R true,ud,k (n) represents the true space distance that the uplink signal and the downlink signal pass through in the k-th slave retransmission ranging signal at the n-th moment, unit: meter; I uu,k (n), I ud,k (n) represents the ionospheric delay of the uplink signal and the downlink signal in the k-th slave retransmission ranging signal at the n-th moment, unit: meter; T duiliu,uu,k (n), T duiliu,ud,k (n) represents the tropospheric delay of the uplink signal and the downlink signal in the k-th slave retransmission ranging signal at the n-th moment, unit: meter; Y u,k (n) represents the hardware device delay of the k-th slave retransmission ranging signal at the n-th moment, unit: meter. The hardware device delay of the slave retransmission ranging signal includes the transmission delay of the uplink signal numbered k, the retransmission delay of the satellite generating the downlink signal numbered k, and the reception delay of the downlink signal numbered k.

13. The method according to claim 11, characterized in that, Determine the relative clock offset between the self-transmitting and self-receiving end and the relay end based on each of the long pseudo-range ranging values, each of the master relay ranging values, each of the slave relay ranging values, and the first preset carrier frequency relationship characterized by the corresponding expressions, including: Perform corrections on the m long pseudo-range ranging values characterized by the long pseudo-range ranging expression to obtain m corrected long pseudo-range ranging values, and perform an average calculation on the m corrected long pseudo-range ranging values to obtain a corrected average long pseudo-range ranging value; Perform corrections on the h master relay ranging values characterized by the relay ranging expression to obtain h corrected master relay ranging values, and perform an average calculation on the h corrected master relay ranging values to obtain h corrected average master relay ranging values; Perform corrections on the r slave relay ranging values characterized by the relay ranging expression to obtain r corrected slave relay ranging values, and perform an average calculation on the r corrected slave relay ranging values to obtain a corrected average slave relay ranging value; Determine the relative clock offset between the self-transmitting and self-receiving end and the relay end based on the corrected average long pseudo-range ranging value, the corrected average master relay ranging value, the corrected average slave relay ranging value, and the first preset carrier frequency relationship.

14. The method according to claim 13, wherein The master pseudo-range ranging device and the master relay ranging device in the self-transmitting and self-receiving end are set with zero baselines, and the slave relay ranging device and the slave pseudo-range ranging device in the relay end are set with zero baselines; determining the relative clock offset between the self-transmitting and self-receiving end and the relay end based on the corrected average long pseudo-range ranging value, the corrected average master relay ranging value, the corrected average slave relay ranging value, and the first preset carrier frequency relationship includes: Determine the relative clock offset between the self-transmitting and self-receiving end and the relay end shown in the following formula (u9) based on the corrected average long pseudo-range ranging value, the corrected average master relay ranging value, the corrected average slave relay ranging value, and the first preset carrier frequency relationship: Where: ρ p,mean (n) represents the corrected average long pseudorange ranging value at the nth moment, unit: meter; L z,mean (n) represents the corrected average master retransmission ranging value at the nth moment, unit: meter; L u,mean (n) represents the corrected average slave retransmission ranging value at the nth moment, unit: meter; c represents the speed of light, unit: meter / second; δt z (n) represents the clock offset of the self-transmitting and self-receiving end relative to the system time at the nth moment, unit: second; δt u (n) represents the clock offset of the retransmission end relative to the system time at the nth moment, unit: second; ±(δt u (n) - δt z (n)) c represents the relative clock offset between the self-transmitting and self-receiving end and the retransmission end calculated at the nth moment, unit: second.

15. The method according to claim 13, characterized in that The performing corrections on the m long pseudo-range ranging values characterized by the long pseudo-range ranging expression to obtain m corrected long pseudo-range ranging values, and performing an average calculation on the m corrected long pseudo-range ranging values to obtain a corrected average long pseudo-range ranging value includes: Perform corrections on each of the long pseudo-range ranging values characterized by the following formula (p1) to obtain m corrected long pseudo-range ranging values shown in the formula (p1'): Perform an average calculation on the m corrected long pseudo-range ranging values shown in the formula (p1') to obtain a corrected average long pseudo-range ranging value shown in the formula (u5): where i = 1, 2, ……, m, and i and m are positive integers; Performing correction on h master forward ranging values characterized by a forward ranging expression to obtain h corrected master forward ranging values, and performing an average calculation on the h corrected master forward ranging values to obtain h corrected average master forward ranging values, includes: Performing correction on each master forward ranging value characterized by the following formula (z1) to obtain h corrected master forward ranging values as shown in formula (z1'): L z,j (n) = R true,zu,j (n) + R true,zd,j (n) + I zu,j (n) + I zd,j (n) + T duiliu,zu,j (n) + T duiliu,zd,j (n) + Y z,j (n)(z1); Performing an average calculation on the h corrected master forward ranging values to obtain a corrected average master forward ranging value as shown in formula (u6): Where j = 1, 2, ……, h, and j and h are positive integers; Performing correction on r slave forward ranging values characterized by a forward ranging expression to obtain r corrected slave forward ranging values, and performing an average calculation on the r corrected slave forward ranging values to obtain a corrected average slave forward ranging value, includes: Performing correction on each slave forward ranging value characterized by the following formula (u1) to obtain r corrected slave forward ranging values as shown in formula (u1'): L u,k (n) = R true,uu,k (n) + R true,ud,k (n) + I uu,k (n) + I ud,k (n) + T duiliu,uu,k (n) + T duiliu,ud,k (n) + Y u,k (n)(u1); Performing an average calculation on the r corrected slave forward ranging values to obtain a corrected average slave forward ranging value as shown in formula (u7): Where k = 1, 2, ……, r, and k and r are positive integers; Where: ρ p,mean (n) represents the corrected average long pseudorange ranging value at the nth moment, unit: meter; ρ p,i,a (n) represents the corrected long pseudorange ranging value with number i at the nth moment, unit: meter; ρ p,i (n) represents the long pseudorange ranging value with number i at the nth moment, unit: meter; R true,pu,i (n), R true,pd,i (n) represents the actual space distance that the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal with number i at the nth moment passes through, unit: meter; I pu,i (n), I pd,i (n) represents the ionospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal with number i at the nth moment, unit: meter; T duiliu,pu,i (n), T duiliu,pd,i (n) represents the tropospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal with number i at the nth moment, unit: meter; c represents the speed of light, unit: meter / second; δt z (n) represents the clock offset of the spontaneous self-receiving end relative to the system time at the nth moment, unit: second; δt u (n) represents the clock offset of the transponder relative to the system time at the nth moment, unit: second; sagnac zz (n) represents the Sagnac effect delay of the pseudorange uplink signal at the nth moment, unit: meter; sagnac uu (n) represents the Sagnac effect delay of the pseudorange downlink signal at the nth moment, unit: meter; X p,i (n) represents the hardware device delay of the long pseudorange ranging signal with number i at the nth moment, unit: meter. The hardware device delay of the long pseudorange ranging signal includes the transmission delay of the pseudorange uplink signal of the long pseudorange ranging signal with number i, the transponder delay of the satellite for forwarding the pseudorange uplink signal of the long pseudorange ranging signal with number i to form the pseudorange downlink signal of the long pseudorange ranging signal with number i, and the reception delay of the pseudorange downlink signal of the long pseudorange ranging signal with number i; L z,mean L(n) represents the corrected average main forward ranging value at the nth moment, unit: meter; z,j,a Lj(n) represents the corrected main forward ranging value with number j at the nth moment, unit: meter; z,j Rj(n) represents the main forward ranging value with number j at the nth moment, unit: meter; true,zu,j Rj(n), R true,zd,j Ij(n) represents the real space distance that the main uplink signal and the main downlink signal in the main forward ranging signal with number j pass through at the nth moment, unit: meter; zu,j Ij(n), I zd,j Tj(n) represents the ionospheric delay of the main uplink signal and the main downlink signal in the main forward ranging signal with number j at the nth moment, unit: meter; duiliu,zu,j Tj(n), T duiliu,zd,j Yj(n) represents the tropospheric delay of the main uplink signal and the main downlink signal in the main forward ranging signal with number j at the nth moment, unit: meter; z,j Hj(n) represents the hardware device delay of the main forward ranging signal with number j at the nth moment, unit: meter. The hardware device delay of the main forward ranging signal includes the transmission delay of the main uplink signal with number j, the forwarding delay of the main downlink signal generated by the satellite with number j, and the reception delay of the main downlink signal with number j; L u,mean L(n) represents the corrected average ranging value at the nth moment, unit: meter; u,k,a L(n) represents the corrected ranging value of the jth number at the nth moment, unit: meter; u,k R(n) represents the ranging value of the kth number at the nth moment, unit: meter; true,uu,k L(n), R(n) true,ud,k I(n) represents the true space distance passed by the uplink signal and the downlink signal in the ranging signal of the kth number at the nth moment, unit: meter; uu,k I(n), L(n) ud,k T(n) represents the ionospheric delay of the uplink signal and the downlink signal in the ranging signal of the kth number at the nth moment, unit: meter; duiliu,uu,k T(n), L(n) duiliu,ud,k Y(n) represents the tropospheric delay of the uplink signal and the downlink signal in the ranging signal of the kth number at the nth moment, unit: meter; u,k H(n) represents the hardware device delay of the ranging signal of the kth number at the nth moment, unit: meter. The hardware device delay of the ranging signal includes the transmission delay of the uplink signal of the kth number, the forwarding delay of the satellite generating the downlink signal of the kth number, and the reception delay of the downlink signal of the kth number.

16. The method according to claim 11, wherein, After determining the relative clock difference between the self-transmitting and self-receiving end and the forwarding end, the method further includes: Communicating with the self-transmitting and self-receiving end and / or the forwarding end, and transmitting the relative clock difference to the self-transmitting and self-receiving end and / or the forwarding end to achieve time synchronization between the self-transmitting and self-receiving end and the forwarding end; Where when the clock difference of the self-transmitting and self-receiving end relative to the system time is known, the forwarding end determines its own clock difference relative to the system time according to the relative clock difference; When the clock difference of the forwarding end relative to the system time is known, the self-transmitting and self-receiving end determines its own clock difference relative to the system time according to the relative clock difference.

17. A new type of high-precision retransmission satellite time synchronization method, characterized in that, Applied to the novel high-precision forwarding satellite time synchronization system according to any one of claims 1-9, the method is executed by a computing device, and the method includes: Obtaining m long pseudo-range ranging values and s long forward ranging values based on the communication results with the self-transmitting and self-receiving end and the forwarding end, where the long forward ranging value is measured by the self-transmitting and self-receiving end for the long forward ranging signal, and the long pseudo-range ranging value is measured by the self-transmitting and self-receiving end or the forwarding end for the long pseudo-range ranging signal, and m and s are both positive integers; Respectively using a long pseudo-range ranging expression to characterize the long pseudo-range ranging values and using a long forward ranging expression to characterize the long forward ranging values; Determining the relative clock difference between the self-transmitting and self-receiving end and the forwarding end based on each of the long pseudo-range ranging values, each of the long forward ranging values characterized by the corresponding expression, and the second preset carrier frequency relationship.

18. The method according to claim 17, wherein The respectively using a long pseudo-range ranging expression to characterize the long pseudo-range ranging values and using a long forward ranging expression to characterize the long forward ranging values includes: Using the long pseudo-range ranging expression shown in the following formula (p1) to characterize each of the long pseudo-range ranging values: Where i = 1, 2, ……, m, and i and m are positive integers; Using the long forward ranging expression shown in the following formula (u2) to characterize each of the long forward ranging values: where \(e = 1, 2, \ldots, s\), and \(e\) and \(s\) are positive integers; Where: ρ p,i (n) represents the long pseudorange ranging value numbered i at the nth moment, unit: meter; R true,pu,i (n), R true,pd,i (n) represents the actual space distance passed by the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal numbered i at the nth moment, unit: meter; I pu,i (n), I pd,i (n) represents the ionospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal numbered i at the nth moment, unit: meter; T duiliu,pu,i (n), T duiliu,pd,i (n) represents the tropospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal numbered i at the nth moment, unit: meter; c represents the speed of light, unit: meter / second; δt z (n) represents the clock error of the self-transmitting and self-receiving end relative to the system time at the nth moment, unit: second; δt u (n) represents the clock error of the forwarding end relative to the system time at the nth moment, unit: second; sagnac zz (n) represents the Sagnac effect delay of the pseudorange uplink signal at the nth moment, unit: meter; sagnac uu (n) represents the Sagnac effect delay of the pseudorange downlink signal at the nth moment, unit: meter; X p,i (n) represents the hardware device delay of the long pseudorange ranging signal numbered i at the nth moment, unit: meter. The hardware device delay of the long pseudorange ranging signal includes the transmission delay of the pseudorange uplink signal of the long pseudorange ranging signal numbered i, the forwarding delay of the satellite for forwarding the pseudorange uplink signal of the long pseudorange ranging signal numbered i to form the pseudorange downlink signal of the long pseudorange ranging signal numbered i, and the reception delay of the pseudorange downlink signal of the long pseudorange ranging signal numbered i; L on,e (n) represents the long forward ranging value numbered e at the nth moment, unit: meter; R true,zu,e (n), R true,zd,e (n) represents the actual space distance passed by the first uplink signal and the second downlink signal between the self-transmitting and self-receiving end and the satellite in the long forward ranging signal numbered e at the nth moment, unit: meter; I zu,e (n), I zd,e (n) represents the ionospheric delay of the first uplink signal and the second downlink signal between the self-transmitting and self-receiving end and the satellite in the long forward ranging signal numbered e at the nth moment, unit: meter; T duiliu,zu,e (n), T duiliu,zd,e (n) represents the tropospheric delay of the first uplink signal and the second downlink signal between the self-transmitting and self-receiving end and the satellite in the long forward ranging signal numbered e at the nth moment, unit: meter; R true,uu,e (n), R true,ud,e (n) represents the actual space distance passed by the first downlink signal and the second uplink signal between the transponder and the satellite in the long forward ranging signal numbered e at the nth moment, unit: meter; I uu,e (n), I ud,e (n) represents the ionospheric delay of the first downlink signal and the second uplink signal between the transponder and the satellite in the long forward ranging signal numbered e at the nth moment, unit: meter; T duiliu,uu,e (n), T duiliu,ud,e (n) represents the tropospheric delay of the first downlink signal and the second uplink signal between the transponder and the satellite in the long forward ranging signal numbered e at the nth moment, unit: meter; Y on,e (n) represents the hardware device delay of the long forward ranging signal numbered e at the nth moment, unit: meter. The hardware device delay includes the transmission and reception delays of the first uplink signal and the second downlink signal in the long forward ranging signal numbered e by the self-transmitting and self-receiving end, and the transponder delays of the satellite and the transponder for the long forward ranging signal numbered e.

19. The method according to claim 17, wherein Determining the relative clock offset between the self - receiving and transmitting end and the forwarding end based on each of the long pseudo - range ranging values, each of the long re - transmission ranging values, and the relationship of the second preset carrier frequency, includes: Correcting \(m\) long pseudo - range ranging values represented by the long pseudo - range ranging expression to obtain \(m\) corrected long pseudo - range ranging values, and calculating the average of the \(m\) corrected long pseudo - range ranging values to obtain the corrected average long pseudo - range ranging value; Correcting \(s\) long re - transmission ranging values represented by the long re - transmission ranging expression to obtain \(s\) corrected long re - transmission ranging values, and calculating the average of the \(s\) corrected long re - transmission ranging values to obtain the corrected average long re - transmission ranging value; Determining the relative clock offset between the self - receiving and transmitting end and the forwarding end based on the corrected average long pseudo - range ranging value, the corrected average long re - transmission ranging value, and the relationship of the second preset carrier frequency.

20. The method according to claim 19, wherein The main pseudo - range ranging device and the main re - transmission ranging device in the self - receiving and transmitting end are set with zero baseline, and the slave re - transmission ranging device and the slave pseudo - range ranging device in the forwarding end are set with zero baseline; determining the relative clock offset between the self - receiving and transmitting end and the forwarding end based on the corrected average long pseudo - range ranging value, the corrected average long re - transmission ranging value, and the relationship of the second preset carrier frequency, includes: Based on the corrected average long pseudo - range ranging value, the corrected average long re - transmission ranging value, and the relationship of the second preset carrier frequency, determining the relative clock offset between the self - receiving and transmitting end and the forwarding end as shown in the following formula (u10): Where: ρ p,mean (n) represents the corrected average long pseudorange ranging value at the nth moment, unit: meter; L on,mean (n) represents the corrected average long retransmission ranging value at the nth moment, unit: meter; c represents the speed of light, unit: meter / second; δt z (n) represents the clock offset of the self-transmitting and self-receiving end relative to the system time at the nth moment, unit: second; δt u (n) represents the clock offset of the retransmission end relative to the system time at the nth moment, unit: second; ±(δt u (n) - δt z (n)) c represents the relative clock offset between the self-transmitting and self-receiving end and the retransmission end calculated at the nth moment, unit: second.

21. The method according to claim 19, characterized in that, The step of correcting \(m\) long pseudo - range ranging values represented by the long pseudo - range ranging expression to obtain \(m\) corrected long pseudo - range ranging values, and calculating the average of the \(m\) corrected long pseudo - range ranging values to obtain the corrected average long pseudo - range ranging value, includes: Correcting each long pseudo - range ranging value represented by the following formula (p1) to obtain \(m\) corrected long pseudo - range ranging values as shown in formula (p1'): Calculating the average of the \(m\) corrected long pseudo - range ranging values shown in formula (p1') to obtain the corrected average long pseudo - range ranging value as shown in formula (u5): where \(i = 1, 2, \ldots, m\), and \(i\) and \(m\) are positive integers; The step of correcting \(s\) long re - transmission ranging values represented by the long re - transmission ranging expression to obtain \(s\) corrected long re - transmission ranging values, and calculating the average of the \(s\) corrected long re - transmission ranging values to obtain the corrected average long re - transmission ranging value, includes: Correcting each long re - transmission ranging value represented by the following formula (u2) to obtain \(s\) corrected long re - transmission ranging values shown in formula (u2'): Calculating the average of the \(s\) corrected long re - transmission ranging values shown in formula (u2') to obtain the corrected average long re - transmission ranging value as shown in formula (u8): where \(e = 1, 2, \ldots, s\), and \(e\) and \(s\) are positive integers; Where: ρ p,mean (n) represents the corrected average long pseudorange ranging value at the nth moment, unit: meter; ρ p,i,a (n) represents the corrected long pseudorange ranging value with serial number i at the nth moment, unit: meter; ρ p,i (n) represents the long pseudorange ranging value with serial number i at the nth moment, unit: meter; R true,pu,i (n), R true,pd,i (n) represents the actual space distance that the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal with serial number i pass through at the nth moment, unit: meter; I pu,i (n), I pd,i (n) represents the ionospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal with serial number i at the nth moment, unit: meter; T duiliu,pu,i (n), T duiliu,pd,i (n) represents the tropospheric delay of the pseudorange uplink signal and / or pseudorange downlink signal of the long pseudorange ranging signal with serial number i at the nth moment, unit: meter; c represents the speed of light, unit: meter / second; δt z (n) represents the clock offset of the self-transmitting and self-receiving end relative to the system time at the nth moment, unit: second; δt u (n) represents the clock offset of the forwarding end relative to the system time at the nth moment, unit: second; sagnac zz (n) represents the Sagnac effect delay of the pseudorange uplink signal at the nth moment, unit: meter; sagnac uu (n) represents the Sagnac effect delay of the pseudorange downlink signal at the nth moment, unit: meter; X p,i (n) represents the hardware device delay of the long pseudorange ranging signal with serial number i at the nth moment, unit: meter. The hardware device delay of the long pseudorange ranging signal includes the transmission delay of the pseudorange uplink signal of the long pseudorange ranging signal with serial number i, the forwarding delay of the satellite for forwarding the pseudorange uplink signal of the long pseudorange ranging signal with serial number i to form the pseudorange downlink signal of the long pseudorange ranging signal with serial number i, and the reception delay of the pseudorange downlink signal of the long pseudorange ranging signal with serial number i; L on,mean (n) represents the corrected average long forward ranging value at the nth moment, unit: meter; L on,e,a (n) represents the corrected long forward ranging value with the number e at the nth moment, unit: meter; L on,e (n) represents the long forward ranging value with the number e at the nth moment, unit: meter; R true,zu,e (n), R true,zd,e (n) represents the true space distance passed by the uplink signal and the downlink signal between the self-transmitting and self-receiving end and the satellite in the long forward ranging signal with the number e at the nth moment, unit: meter; I zu,e (n), I zd,e (n) represents the ionospheric delay of the uplink signal and the downlink signal between the self-transmitting and self-receiving end and the satellite in the long forward ranging signal with the number e at the nth moment, unit: meter; T duiliu,zu,e (n), T duiliu,zd,e (n) represents the tropospheric delay of the uplink signal and the downlink signal between the self-transmitting and self-receiving end and the satellite in the long forward ranging signal with the number e at the nth moment, unit: meter; R true,uu,e (n), R true,ud,e (n) represents the true space distance passed by the uplink signal and the downlink signal between the forward end and the satellite in the long forward ranging signal with the number e at the nth moment, unit: meter; I uu,e (n), I ud,e (n) represents the ionospheric delay of the uplink signal and the downlink signal between the forward end and the satellite in the long forward ranging signal with the number e at the nth moment, unit: meter; T duiliu,uu,e (n), T duiliu,ud,e (n) represents the tropospheric delay of the uplink signal and the downlink signal between the forward end and the satellite in the long forward ranging signal with the number e at the nth moment, unit: meter; Y on,e (n) represents the hardware device delay of the long forward ranging signal with the number e at the nth moment, unit: meter. The hardware device delay includes the transmission and reception delays of the first uplink signal and the second downlink signal in the long forward ranging signal with the number e by the self-transmitting and self-receiving end, and the forwarding delays of the satellite and the forward end for the long forward ranging signal with the number e.

22. The method according to claim 17, wherein After determining the relative clock offset between the self - receiving and transmitting end and the forwarding end, the method further includes: Communicating with the self - receiving and transmitting end and / or the forwarding end, and transmitting the relative clock offset to the self - receiving and transmitting end and / or the forwarding end to achieve time synchronization between the self - receiving and transmitting end and the forwarding end; Wherein, when the clock difference of the self-transmitting and self-receiving end relative to the system time is known, the forwarding end determines its own clock difference relative to the system time according to the relative clock difference; When the clock difference of the forwarding end relative to the system time is known, the self-transmitting and self-receiving end determines its own clock difference relative to the system time according to the relative clock difference.

Images