A method for compensating frequency deviation of an RDSS system and an RDSS system

Abstract

The present application relates to the technical field of satellite, in particular to a RDSS system frequency offset compensation method and RDSS system, the present application embodiment provides a kind of frequency offset compensation method of RDSS system, comprising: determining target Beidou satellite;Wherein, the target Beidou satellite is the nearest Beidou satellite of remote sensing satellite or the normal of the antenna of the RDSS system and the angle formed when the straight line connecting the RDSS system and Beidou satellite is at the minimum time corresponding Beidou satellite;According to the speed of remote sensing satellite and the speed of target Beidou satellite, the relative speed between remote sensing satellite and target Beidou satellite is determined;According to the relative speed, frequency offset value is obtained;The sending frequency of the RDSS system is compensated using the frequency offset value.The present application embodiment provides a kind of frequency offset compensation method of RDSS system, and makes remote sensing satellite and Beidou satellite again communicate between disconnection.

Description

Technical Field

[0001] The present invention relates to the field of satellite technology, and in particular to a RDSS system frequency offset compensation method and an RDSS system. Background Art

[0002] Remote sensing satellites equipped with the RDSS (Radio Determination Satellite System) work in conjunction with BeiDou satellites to monitor surface fires. Specifically, fire detection sensors on the RDSS collect fire information, which is then transmitted to BeiDou satellites. Finally, the BeiDou satellites transmit the information to ground terminals.

[0003] However, since remote sensing satellites and Beidou satellites are far apart and information is transmitted via radio waves, the connection between remote sensing satellites and Beidou satellites may be lost due to S-band signal channel failure, resulting in the inability to transmit fire point information to the ground destination.

[0004] Therefore, in response to the above problems, a method for compensating the frequency offset of the RDSS system is urgently needed to enable the lost remote sensing satellite and the Beidou satellite to communicate again. Summary of the Invention

[0005] The embodiment of the present invention provides an RDSS system frequency offset compensation method and an RDSS system, which can provide an RDSS system frequency offset compensation method to enable lost remote sensing satellites and Beidou satellites to communicate again.

[0006] In a first aspect, an embodiment of the present invention provides a frequency offset compensation method for an RDSS system, which is applied to the RDSS system and includes:

[0007] Determine a target Beidou satellite; wherein the target Beidou satellite is the Beidou satellite closest to the remote sensing satellite or the Beidou satellite corresponding to the minimum angle formed by the normal of the antenna of the RDSS system and the straight line connecting the RDSS system and the Beidou satellite;

[0008] Determining the relative speed between the remote sensing satellite and the target Beidou satellite according to the speed of the remote sensing satellite and the speed of the target Beidou satellite;

[0009] obtaining a frequency deviation value according to the relative speed;

[0010] The frequency offset value is used to compensate for the transmission frequency of the RDSS system.

[0011] In a second aspect, an embodiment of the present invention further provides an RDSS system, comprising:

[0012] A fire detection sensor is used to determine a target Beidou satellite, and the fire detection sensor is also used to determine a relative velocity between the remote sensing satellite and the target Beidou satellite according to a velocity of the remote sensing satellite and a velocity of the target Beidou satellite, and the fire detection sensor is also used to obtain a frequency offset value according to the relative velocity;

[0013] An RDSS line is used to compensate a transmitting frequency of the RDSS system by using the frequency offset value.

[0014] The embodiment of the present application provides a method for frequency offset compensation of an RDSS system and the RDSS system, so that the remote sensing satellite and the Beidou satellite can communicate again when the remote sensing satellite and the Beidou satellite are out of contact. When the remote sensing satellite and the Beidou satellite are out of contact, a target Beidou satellite most suitable for reestablishing communication is determined first, and the target Beidou satellite can be the nearest Beidou satellite to the remote sensing satellite, or can be a Beidou satellite corresponding to the smallest angle formed by a normal line of an antenna of the RDSS system and a straight line connecting the RDSS system and the Beidou satellite. Then, a relative velocity between the remote sensing satellite and the target Beidou satellite is determined according to a velocity of the remote sensing satellite and a velocity of the target Beidou satellite. After the relative velocity is determined, a frequency offset value is calculated according to the relative velocity. The transmitting frequency of the RDSS system is compensated by using the obtained frequency offset value, and the compensated transmitting frequency can repair an s-band signal channel, so that the remote sensing satellite and the target Beidou satellite can reestablish contact. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, hereinafter, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort on the basis of these drawings.

[0016] Figure 1 It is a frequency offset compensation method flowchart of an RDSS system provided by the embodiment of the present application;

[0017] Figure 2 It is a structural schematic diagram of an RDSS system provided by the embodiment of the present application. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the embodiments of the present application more clear, hereinafter, the technical solutions in the embodiments of the present application will be clearly and completely described with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without any creative effort belong to the protection scope of the present application.

[0019] Please refer to Figure 1 An embodiment of the present invention provides a frequency offset compensation method for an RDSS system, which is applied to the RDSS system and includes:

[0020] S1: Determine the target Beidou satellite; wherein the target Beidou satellite is the Beidou satellite closest to the remote sensing satellite or the Beidou satellite corresponding to the angle formed by the normal of the antenna of the RDSS system and the straight line connecting the RDSS system and the Beidou satellite is minimum;

[0021] S2: Determine the relative speed between the remote sensing satellite and the target BeiDou satellite based on the speed of the remote sensing satellite and the speed of the target BeiDou satellite;

[0022] S3: Obtaining a frequency deviation value according to the relative speed;

[0023] S4: Use the frequency deviation value to compensate the transmission frequency of the RDSS system.

[0024] In this embodiment, when the remote sensing satellite and the Beidou satellite lose contact, the target Beidou satellite most suitable for re-establishing communication is first determined. The target Beidou satellite can be the Beidou satellite closest to the remote sensing satellite, with minimal free-space loss in the communication link, or it can be the Beidou satellite corresponding to the point where the angle formed between the normal of the RDSS system's antenna and the straight line connecting the RDSS system and the Beidou satellite is minimal, with maximum antenna transmission gain. The relative speed between the remote sensing satellite and the target Beidou satellite is then determined based on the speed of the remote sensing satellite and the speed of the target Beidou satellite. After determining the relative speed, a frequency offset value is calculated based on the relative speed. The obtained frequency offset value is used to compensate for the RDSS system's transmission frequency. The compensated transmission frequency can repair the S-band signal channel, allowing the remote sensing satellite and the target Beidou satellite to re-establish communication.

[0025] It should be noted that after the remote sensing satellite and the target Beidou satellite lose contact, as the remote sensing satellite and the Beidou satellite move, the RDSS system continuously calculates and updates the frequency deviation value and compensates the sending frequency according to the above method until the remote sensing satellite and the target Beidou satellite are connected again.

[0026] In some embodiments of the present invention, the target BeiDou satellite is determined by the following formula:

[0027]

[0028]

[0029]

[0030]

[0031] case1:min(R fG [i])

[0032] case2:min(arccos(α fG [i]))

[0033] Among them, i is the number of different Beidou satellites, R fG [i] is the distance between the remote sensing satellite and the BeiDou satellite, is the vector distance between the remote sensing satellite and the BeiDou satellite, X f , Y f , Z f are different coordinate values ​​of the remote sensing satellite in the orbital coordinate system, X G , Y G , Z G are the different coordinate values ​​of BeiDou satellite in the orbital coordinate system, is the vector of the antenna normal direction of the RDSS system, for is the transposed vector of , α fG [i] is and The angle between them, min(R fG [i]) is the BeiDou satellite closest to the remote sensing satellite, min(arccos(α fG [i])) is the BeiDou satellite with the smallest angle between the RDSS system antenna normal and the straight line connecting the RDSS system and the BeiDou satellite.

[0034] In some embodiments of the present invention, the relative speed is determined by the following formula:

[0035]

[0036] Among them, v fG is the relative speed, i is the number of different BeiDou satellites, VX f , VY f , VZ f is the component of the remote sensing satellite's velocity in different directions in the orbital coordinate system, VX G , VY G , VZ G are the components of the Beidou satellite's velocity in different directions in the orbital coordinate system.

[0037] In some embodiments of the present invention, after determining the target Beidou satellite and before determining the relative speed between the remote sensing satellite and the target Beidou satellite based on the speed of the remote sensing satellite and the speed of the target Beidou satellite, the method further includes:

[0038] Collect remote sensing satellite orbit data and calculate the speed of the remote sensing satellite based on the remote sensing satellite orbit data.

[0039] In this embodiment, the fire detection sensor in the RDSS system regularly (can be every other day, can be every half day) receives the orbit data of the remote sensing satellite sent by the central control unit. The fire detection sensor performs orbit extrapolation based on the orbit data of the remote sensing satellite, and calculates and corrects the orbital position and speed of the remote sensing satellite in real time.

[0040] It's important to note that the fire detection sensor only needs to periodically receive orbital data from remote sensing satellites. Based on this data, it can infer the satellite's orbital position and velocity at the time of the incident. Once the satellite receives orbital data again, it can perform a new calculation based on the updated data. This setup eliminates the need for constant orbital data transmission; only periodic updates are needed for corrections.

[0041] In some embodiments of the present invention, after determining the target Beidou satellite and before determining the relative speed between the remote sensing satellite and the target Beidou satellite based on the speed of the remote sensing satellite and the speed of the target Beidou satellite, the method further includes:

[0042] Collect Beidou satellite orbit data and calculate the speed of the target Beidou satellite based on the Beidou satellite orbit data.

[0043] In this embodiment, the fire detection sensor in the RDSS system regularly (can be every other day, can be every half day) receives the orbit data of the target Beidou satellite sent by the central control unit. The fire detection sensor performs orbit extrapolation based on the orbit data of the target Beidou satellite, and calculates and corrects the orbital position and speed of the target Beidou satellite in real time.

[0044] It's important to note that the fire detection sensor only needs to periodically receive orbital data from the target BeiDou satellite. Based on this data, it can infer the target BeiDou satellite's orbital position and velocity at the time of the incident. It then waits until it receives orbital data from the target BeiDou satellite again, recalculating the prediction based on the new data. This setup eliminates the need for constant orbital data transmission; it only needs to periodically receive new data for correction.

[0045] In the present invention, the 19-element method is generally used to perform real-time orbit calculation, and the numerical integration on-board orbit extrapolation algorithm is used to perform real-time orbit calculation for the five Beidou satellites.

[0046] In some embodiments of the present invention, the frequency offset value is determined by the following formula:

[0047]

[0048] Where f is the frequency deviation value, c is the speed of light, v fG is the relative speed, and B is the transmission frequency of Beidou satellite.

[0049] In this embodiment, the transmission frequency B of the Beidou satellite may be 1615.68 MHz.

[0050] Please refer to Figure 2 , an embodiment of the present invention further provides an RDSS system, the system comprising:

[0051] A fire detection sensor is used to determine the target Beidou satellite. The fire detection sensor is also used to determine the relative speed between the remote sensing satellite and the target Beidou satellite based on the speed of the remote sensing satellite and the speed of the target Beidou satellite. The fire detection sensor is also used to obtain a frequency deviation value based on the relative speed;

[0052] The RDSS line is used to compensate the transmission frequency of the RDSS system using a frequency offset value.

[0053] In some embodiments of the present invention, the target BeiDou satellite is determined by the following formula:

[0054]

[0055]

[0056]

[0057]

[0058] case1:min(R fG [i])

[0059] case2:min(arccos(α fG [i]))

[0060] Among them, i is the number of different Beidou satellites, R fG [i] is the distance between the remote sensing satellite and the BeiDou satellite, is the vector distance between the remote sensing satellite and the BeiDou satellite, X f , Y f , Z f are different coordinate values ​​of the remote sensing satellite in the orbital coordinate system, X G , Y G , Z G are the different coordinate values ​​of BeiDou satellite in the orbital coordinate system, is the vector of the antenna normal direction of the RDSS system, for is the transposed vector of , α fG [i] is and The angle between them, min(R fG [i]) is the BeiDou satellite closest to the remote sensing satellite, min(arccos(α fG[i])) is the BeiDou satellite with the smallest angle between the RDSS system antenna normal and the straight line connecting the RDSS system and the BeiDou satellite.

[0061] In some embodiments of the present invention, the relative speed is determined by the following formula:

[0062]

[0063] Among them, v fG is the relative speed, i is the number of different BeiDou satellites, VX f , VY f , VZ f is the component of the remote sensing satellite's velocity in different directions in the orbital coordinate system, VX G , VY G , VZ G are the components of the Beidou satellite's velocity in different directions in the orbital coordinate system.

[0064] In some embodiments of the present invention, the frequency offset value is determined by the following formula:

[0065]

[0066] Where f is the frequency deviation value, c is the speed of light, v fG is the relative speed, and B is the transmission frequency of Beidou satellite.

[0067] In some embodiments of the present invention, a central control unit is further included, and the central control unit is used to collect remote sensing satellite orbit data;

[0068] The fire detection sensor is also used to extrapolate the speed of the remote sensing satellite based on the remote sensing satellite orbit data.

[0069] In some embodiments of the present invention, the central control unit is used to collect Beidou satellite orbit data;

[0070] The fire detection sensor is also used to extrapolate and calculate the speed of the target Beidou satellite based on the Beidou satellite orbit data.

[0071] In this embodiment, the fire detection sensor receives the current satellite orbit data and the orbit data of 5 BeiDou-2 GEO satellites injected by the central control unit every day, and performs satellite orbit and second-generation GEO satellite orbit extrapolation in real time; after the fire detection sensor receives the frequency deviation calculation instruction allowed by the central control unit, it starts to call the frequency deviation calculation module, judges the visibility of the 5 GEO satellites at this time according to the current position of the satellite, and selects the satellite closest (with the smallest free space loss of the communication link) or with the smallest angle relative to the normal direction of the RDSS antenna (with the largest RDSS antenna transmission gain); according to the satellite orbit parameters, calculates the relative speed v between the satellite and a certain BeiDou-2 GEO satellite as an alternative, and then calculates the Doppler frequency deviation f for compensation; the fire point detection sensor sends the DPL instruction through the serial port according to the protocol in Table 1, and sends the frequency deviation compensation value to the RDSS line every fixed period Tf (initial value 1s); then the fire point detection sensor sends the MFS instruction to the RDSS through the serial port, Turn on the blind transmit switch; upon receiving the MFS command, the RDSS is set to blind transmit mode. If the RDSS transmits without receiving the DPL command, the transmit frequency compensation is 0. If it has received the DPL command, the transmit frequency compensation is the last DPL input value, and the main beam is set to the last DPL input value. If the input satellite number is 1 (i.e., the target Beidou satellite number is 1), the main beam is set to 1; if the input satellite number is 2 (i.e., the target Beidou satellite number is 2), the main beam is set to 3; if the input satellite number is 3 (i.e., the target Beidou satellite number is 3), the main beam is set to 5; if the input satellite number is 4 (i.e., the target Beidou satellite number is 4), the main beam is set to 7; if the input satellite number is 5 (i.e., the target Beidou satellite number is 5), the main beam is set to 9. In blind transmit mode, the RDSS has no acquisition beam. The fire point detection sensor should periodically send the DPL command and the TXA command (fire information) according to the frequency to ensure reliable transmission of fire information. The above method can effectively solve the problem of the RDSS subsystem failing to operate due to a failure in receiving the S signal, thereby improving system reliability.

[0072] Table 1

[0073]

[0074]

[0075] It should be noted that the numbers of the above main beam settings have no practical meaning. Different Beidou satellites have different main beam frequencies, and the numbers are only used to distinguish different main beams.

[0076] It should be noted that, in this document, relational terms such as first and second are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus.

[0077] Those skilled in the art will understand that all or part of the steps of implementing the above-mentioned method embodiment can be completed by hardware related to program instructions, and the aforementioned program can be stored in a computer-readable storage medium. When the program is executed, it executes the steps of the above-mentioned method embodiment; and the aforementioned storage medium includes: ROM, RAM, disk or optical disk, etc. Various media that can store program codes.

[0078] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.

Claims

1. A frequency offset compensation method for an RDSS system, characterized in that: Applied to RDSS system, including: Determine a target Beidou satellite; wherein the target Beidou satellite is the Beidou satellite closest to the remote sensing satellite or the Beidou satellite corresponding to the minimum angle formed by the normal of the antenna of the RDSS system and the straight line connecting the RDSS system and the Beidou satellite; Determining the relative speed between the remote sensing satellite and the target Beidou satellite according to the speed of the remote sensing satellite and the speed of the target Beidou satellite; obtaining a frequency deviation value according to the relative speed; Compensating a transmission frequency of the RDSS system using the frequency offset value; The target BeiDou satellite is determined by the following formula: case1:min(R fG [i]) case2:min(arccos(α fG [in])) Wherein, i is the number of different BeiDou satellites, R fG [i] is the distance between the remote sensing satellite and the BeiDou satellite, is the vector distance between the remote sensing satellite and the BeiDou satellite, X f , Y f , Z f are different coordinate values ​​of the remote sensing satellite in the orbital coordinate system, X G , Y G , Z G are the different coordinate values ​​of the BeiDou satellite in the orbital coordinate system, is the vector of the antenna normal direction of the RDSS system, for The transposed vector of fG [i] is and The angle between them, min(R fG [i]) is the BeiDou satellite closest to the remote sensing satellite, min(arccos(α fG [i])) is the Beidou satellite whose angle between the normal line of the RDSS system antenna and the straight line connecting the RDSS system and the Beidou satellite is the smallest.

2. The method according to claim 1, characterized in that The relative speed is determined by the following formula: Among them, v fG is the relative speed, i is the number of different BeiDou satellites, VX f , VY f , VZ f is the component of the remote sensing satellite's velocity in different directions in the orbital coordinate system, VX G , VY G , VZ G are the components of the BeiDou satellite's velocity in different directions in the orbital coordinate system.

3. The method according to claim 1, characterized in that After determining the target Beidou satellite and before determining the relative speed between the remote sensing satellite and the target Beidou satellite based on the speed of the remote sensing satellite and the speed of the target Beidou satellite, the method further includes: Remote sensing satellite orbit data is collected, and the speed of the remote sensing satellite is calculated by extrapolation based on the remote sensing satellite orbit data.

4. The method according to claim 3, characterized in that After determining the target Beidou satellite and before determining the relative speed between the remote sensing satellite and the target Beidou satellite based on the speed of the remote sensing satellite and the speed of the target Beidou satellite, the method further includes: Beidou satellite orbit data is collected, and the speed of the target Beidou satellite is calculated by extrapolation based on the Beidou satellite orbit data.

5. The method according to claim 1, wherein The frequency deviation value is determined by the following formula: Wherein, f is the frequency deviation value, c is the speed of light, v fG is the relative speed, and B is the transmission frequency of the Beidou satellite.

6. An RDSS system, characterized in that: include: A fire detection sensor is used to determine a target Beidou satellite. The fire detection sensor is further used to determine the relative speed between the remote sensing satellite and the target Beidou satellite based on the speed of the remote sensing satellite and the speed of the target Beidou satellite. The fire detection sensor is further used to obtain a frequency deviation value based on the relative speed. The target Beidou satellite is the Beidou satellite closest to the remote sensing satellite or the Beidou satellite corresponding to the minimum angle formed by the normal of the antenna of the RDSS system and the straight line connecting the RDSS system and the Beidou satellite. An RDSS circuit, configured to compensate for a transmission frequency of the RDSS system using the frequency offset value; The target BeiDou satellite is determined by the following formula: case1:min(R fG [i]) case2:min(arccos(α fG [in])) Wherein, i is the number of different BeiDou satellites, R fG [i] is the distance between the remote sensing satellite and the BeiDou satellite, is the vector distance between the remote sensing satellite and the BeiDou satellite, X f , Y f , Z f are different coordinate values ​​of the remote sensing satellite in the orbital coordinate system, X G , Y G , Z G are the different coordinate values ​​of the BeiDou satellite in the orbital coordinate system, is the vector of the antenna normal direction of the RDSS system, for The transposed vector of fG [i] is and The angle between them, min(R fG [i]) is the BeiDou satellite closest to the remote sensing satellite, min(arccos(α fG [i])) is the Beidou satellite whose angle between the normal line of the RDSS system antenna and the straight line connecting the RDSS system and the Beidou satellite is the smallest.

7. The system according to claim 6, characterized in that The relative speed is determined by the following formula: Among them, v fG is the relative speed, i is the number of different BeiDou satellites, VX f , VY f , VZ f is the component of the remote sensing satellite's velocity in different directions in the orbital coordinate system, VX G , VY G , VZ G are the components of the BeiDou satellite's velocity in different directions in the orbital coordinate system; and / or, The frequency deviation value is determined by the following formula: Wherein, f is the frequency deviation value, c is the speed of light, v fG is the relative speed, and B is the transmission frequency of the Beidou satellite.

8. The system according to claim 6, wherein: It also includes a central control unit, which is used to collect remote sensing satellite orbit data; The fire detection sensor is further used to calculate the speed of the remote sensing satellite based on the orbital data of the remote sensing satellite; and / or, The central control unit is used to collect Beidou satellite orbit data; The fire detection sensor is also used to extrapolate and calculate the speed of the target Beidou satellite based on the Beidou satellite orbit data.

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