Method and system for processing pseudo-range difference observed quantity of opportunistic signal of low earth orbit satellite

Abstract

The invention discloses a low earth orbit satellite opportunity signal pseudo range difference observed quantity processing method and system. The method comprises the following steps: receiving a plurality of low earth orbit satellite opportunity signals and obtaining a baseband opportunity signal corresponding to each low earth orbit satellite opportunity signal; performing sliding correlation on the synchronous code sequence signal and a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal to obtain synchronous code arrival time corresponding to each low-orbit satellite opportunity signal; and carrying out difference on the synchronous code arrival time corresponding to different low-orbit satellite opportunity signals, and determining a pseudo-range difference observed quantity between the different low-orbit satellite opportunity signals. According to the invention, the technical problem that the low-earth-orbit satellite opportunity signal cannot be fully utilized due to the unknown navigation message format of the low-earth-orbit satellite opportunity signal in the prior art is solved, the problem that the navigation message format of the low-earth-orbit satellite opportunity signal is unknown is solved, available ranging information is obtained, and the user experience is improved. The technical effect of more fully utilizing the opportunity signal of the low-orbit satellite is achieved.

Description

Technical Field

[0001] The present invention relates to the field of signal processing technology, and in particular to a method and system for processing pseudo-range difference observations of low-orbit satellite opportunity signals. Background Art

[0002] The Global Navigation Satellite System (GNSS) is becoming more and more sophisticated and has been widely used in various military and civilian fields. However, GNSS signals have inherent vulnerabilities: the GNSS system is composed of medium and high orbit satellites, and the power of the signal reaching the ground is low; the GNSS signal frequency band is narrow and is easily lost due to attacks. The above two vulnerabilities make GNSS signals less resistant to interference in space environments. In some scenarios, relying solely on GNSS navigation will pose huge security risks.

[0003] In recent years, many teams have devoted themselves to studying navigation backup in GNSS failure environments. Opportunity signals are radio signals that exist in the environment and are not dedicated to positioning. Space-based low-orbit satellite opportunity signals have the advantages of global coverage, all-weather existence, and high power reaching the ground. These advantages enable low-orbit satellite opportunity signals to effectively overcome the shortcomings of the GNSS system and become an excellent choice for GNSS navigation backup. At present, low-orbit satellite opportunity signal positioning technology has been realized. However, due to the restriction that there is no dedicated navigation message for opportunity signals, low-orbit satellite opportunity signal positioning mostly uses Doppler positioning, and the positioning means are relatively limited. Further research is needed to make full use of signals and more diverse positioning technology methods. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is to overcome the technical problem in the related art that the low-orbit satellite opportunity signal cannot be fully utilized due to the unknown navigation message format of the low-orbit satellite opportunity signal, thereby providing a method and system for processing the pseudo-range difference observation of the low-orbit satellite opportunity signal.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides a method for processing pseudorange difference observations of low-orbit satellite opportunity signals, comprising the following steps: receiving multiple low-orbit satellite opportunity signals, and obtaining a carrier having the same frequency as each of the low-orbit satellite opportunity signals; performing carrier demodulation on the corresponding low-orbit satellite opportunity signals based on the carrier corresponding to each of the low-orbit satellite opportunity signals, to obtain a baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals; obtaining a synchronization code sequence signal, and slidingly correlating the synchronization code sequence signal with the baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, to obtain a synchronization code arrival time corresponding to each of the low-orbit satellite opportunity signals; and differentiating the synchronization code arrival times corresponding to different low-orbit satellite opportunity signals to determine the pseudorange difference observations between different low-orbit satellite opportunity signals.

[0007] Furthermore, obtaining a carrier having the same frequency as each of the low-orbit satellite opportunity signals includes: converting each of the low-orbit satellite opportunity signals from the time domain to the frequency domain to obtain the frequency of each of the low-orbit satellite opportunity signals; and generating a carrier corresponding to each of the low-orbit satellite opportunity signals according to the frequency of each of the low-orbit satellite opportunity signals, wherein the carrier corresponding to each of the low-orbit satellite opportunity signals has the same frequency as each of the low-orbit satellite opportunity signals.

[0008] Furthermore, carrier demodulation is performed on the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each of the low-orbit satellite opportunity signals to obtain a baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, including: correlating the carrier corresponding to each of the low-orbit satellite opportunity signals with the corresponding low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, wherein the baseband opportunity signal includes a signal value of a baseband modulation code, a mixed noise of a propagation channel noise and a receiver thermal noise.

[0009] Furthermore, the synchronization code sequence signal is slidingly correlated with the baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals to obtain the synchronization code arrival time corresponding to each of the low-orbit satellite opportunity signals, including: for each of the low-orbit satellite opportunity signals, calculating the correlation value between the synchronization code sequence signal and the baseband opportunity signal corresponding to the low-orbit satellite opportunity signal at each sliding moment; if the correlation value reaches a maximum, determining the signal segment in the low-orbit satellite opportunity signal that has the highest overlap with the synchronization code sequence signal, corresponding to the position of the synchronization code in the baseband opportunity signal, and obtaining the synchronization code arrival time corresponding to the low-orbit satellite opportunity signal.

[0010] Furthermore, the arrival times of synchronization codes corresponding to different said low-orbit satellite opportunity signals are differentiated to determine the pseudorange difference observation amount between different said low-orbit satellite opportunity signals, including: determining the time relationship between transmission and arrival of different synchronization codes; differentiating the arrival times of synchronization codes corresponding to different said low-orbit satellite opportunity signals according to the time relationship between transmission and arrival of different synchronization codes, and calculating the propagation time difference between different said low-orbit satellite opportunity signals; and obtaining the pseudorange difference observation amount between different said low-orbit satellite opportunity signals based on the propagation time difference.

[0011] Furthermore, obtaining a pseudorange difference observation amount between different said low-orbit satellite opportunity signals based on said propagation time difference includes: obtaining a propagation speed of said low-orbit satellite opportunity signal in space; and calculating, according to said propagation time difference and said propagation speed of said low-orbit satellite opportunity signal in space, obtaining a pseudorange difference observation amount between different said low-orbit satellite opportunity signals.

[0012] Furthermore, the expression of the time relationship between the transmission and arrival of different synchronization codes is as follows:

[0013] t sj -t si =N·T 0 (i,j,N∈N * ,j>i),t ai =t si +t di ; Among them, T 0 The time period for transmitting synchronization code of low-orbit satellite; t si is the transmission time of synchronization code i; t ai is the arrival time of synchronization code i; t di is the propagation time of synchronization code i; t sj is the transmission time of synchronization code j; t aj is the arrival time of synchronization code j; t dj is the propagation time of synchronization code j; N is a positive integer; N * is a set of positive integers.

[0014] In a second aspect, the present invention provides a processing system for pseudo-range difference observations of low-orbit satellite opportunity signals, comprising: a first processing module, used to receive multiple low-orbit satellite opportunity signals, and obtain a carrier with the same frequency as each of the low-orbit satellite opportunity signals; a second processing module, used to perform carrier demodulation on the corresponding low-orbit satellite opportunity signals based on the carrier corresponding to each of the low-orbit satellite opportunity signals, to obtain a baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals; a third processing module, used to obtain a synchronization code sequence signal, and perform sliding correlation on the synchronization code sequence signal with the baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, to obtain a synchronization code arrival time corresponding to each of the low-orbit satellite opportunity signals; and a fourth processing module, used to differentiate the synchronization code arrival times corresponding to different low-orbit satellite opportunity signals, to determine the pseudo-range difference observations between different low-orbit satellite opportunity signals.

[0015] In a third aspect, the present invention provides an electronic device, comprising: a processor, and a memory for storing a program, wherein the program comprises instructions, and when the instructions are executed by the processor, the processor executes the method for verifying the accuracy of satellite two-way comparison described above in the first aspect of the embodiment of the present invention.

[0016] In a fourth aspect, a computer-readable storage medium is provided, wherein the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method for verifying the accuracy of a satellite two-way comparison described above in the first aspect of an embodiment of the present invention.

[0017] In an embodiment of the present invention, a plurality of low-orbit satellite opportunity signals are received, and a carrier wave having the same frequency as each low-orbit satellite opportunity signal is obtained; based on the carrier wave corresponding to each low-orbit satellite opportunity signal, the corresponding low-orbit satellite opportunity signal is carrier-demodulated to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal; a synchronization code sequence signal is obtained, and the synchronization code sequence signal is slidingly correlated with the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal to obtain a synchronization code arrival time corresponding to each low-orbit satellite opportunity signal; the synchronization code arrival times corresponding to different low-orbit satellite opportunity signals are differentiated to determine the pseudo-range difference observation amount between different low-orbit satellite opportunity signals, thereby solving the technical problem in the related art that the low-orbit satellite opportunity signal cannot be fully utilized due to the unknown navigation message format of the low-orbit satellite opportunity signal, achieving the technical effect of overcoming the problem of the unknown navigation message format of the low-orbit satellite opportunity signal, obtaining available ranging information, and making more full use of the low-orbit satellite opportunity signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other embodiments can be obtained based on these drawings without creative work.

[0019] Figure 1 A schematic flow chart of a method for processing pseudorange difference observations of low-orbit satellite opportunity signals provided by an embodiment of the present invention;

[0020] Figure 2 A schematic diagram of the time relationship between the transmission and arrival of different synchronization codes of a low-orbit satellite opportunity signal provided by an embodiment of the present invention;

[0021] Figure 3 A schematic diagram of a system for processing pseudorange difference observations of low-orbit satellite opportunity signals provided by an embodiment of the present invention;

[0022] Figure 4 A schematic diagram of the structure of an electronic device provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0023] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the embodiments of the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided to provide a more thorough and complete understanding of the embodiments of the present invention. It should be understood that the drawings and embodiments of the embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the embodiments of the present invention.

[0024] Example 1

[0025] Figure 1 A flowchart of a method for processing pseudo-range difference observations of a low-orbit satellite opportunity signal provided by an embodiment of the present invention is shown in the figure. The steps of a method for processing pseudo-range difference observations of a low-orbit satellite opportunity signal provided by an embodiment of the present invention include:

[0026] Step S102, receiving a plurality of low-orbit satellite opportunity signals, and acquiring a carrier having the same frequency as each low-orbit satellite opportunity signal;

[0027] Step S104, performing carrier demodulation on the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal;

[0028] Step S106, acquiring a synchronization code sequence signal, and slidingly correlating the synchronization code sequence signal with a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, to obtain a synchronization code arrival time corresponding to each low-orbit satellite opportunity signal;

[0029] Step S108, differentiating the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals to determine the pseudo-range difference observations between the different low-orbit satellite opportunity signals.

[0030] The above-mentioned low-orbit satellite opportunity signals include but are not limited to Iridium low-orbit satellite system signals and Orbcomm low-orbit satellite system signals.

[0031] In an embodiment of the present invention, a plurality of low-orbit satellite opportunity signals are received, and a carrier wave having the same frequency as each low-orbit satellite opportunity signal is obtained; based on the carrier wave corresponding to each low-orbit satellite opportunity signal, the corresponding low-orbit satellite opportunity signal is carrier-demodulated to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal; a synchronization code sequence signal is obtained, and the synchronization code sequence signal is slidingly correlated with the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal to obtain a synchronization code arrival time corresponding to each low-orbit satellite opportunity signal; the synchronization code arrival times corresponding to different low-orbit satellite opportunity signals are differentiated to determine the pseudo-range difference observation amount between different low-orbit satellite opportunity signals, thereby solving the technical problem in the related art that the low-orbit satellite opportunity signal cannot be fully utilized due to the unknown navigation message format of the low-orbit satellite opportunity signal, achieving the technical effect of overcoming the problem of the unknown navigation message format of the low-orbit satellite opportunity signal, obtaining available ranging information, and making more full use of the low-orbit satellite opportunity signal.

[0032] It should be noted that based on the synchronization code broadcast by the low-orbit satellite opportunity signal in a time period, the arrival time difference method is used to extract the pseudo-range difference observation between different signal segments. The extraction of pseudo-range difference observation enables the low-orbit satellite to make fuller use of the opportunity signal, and provides a basis for the pseudo-range differential positioning technology of the low-orbit satellite opportunity signal.

[0033] As an optional embodiment, obtaining a carrier having the same frequency as each low-orbit satellite opportunity signal includes: converting each low-orbit satellite opportunity signal from the time domain to the frequency domain to obtain the frequency of each low-orbit satellite opportunity signal; and generating a carrier corresponding to each low-orbit satellite opportunity signal according to the frequency of each low-orbit satellite opportunity signal, wherein the carrier corresponding to each low-orbit satellite opportunity signal has the same frequency as each low-orbit satellite opportunity signal.

[0034] Optionally, a fast Fourier transform (FFT) is used to process the low-orbit satellite opportunity signal s(t) to obtain the frequency of the low-orbit satellite opportunity signal Then the generated frequency is carrier.

[0035] As an optional embodiment, carrier demodulation is performed on the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, including: correlating the carrier corresponding to each low-orbit satellite opportunity signal with the corresponding low-orbit satellite opportunity signal to obtain the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, wherein the baseband opportunity signal includes a signal value of a baseband modulation code, a mixed noise of a propagation channel noise and a receiver thermal noise.

[0036] Optionally, the frequency of The carrier of the opportunity signal is correlated with s(t) to realize carrier demodulation of the opportunity signal and obtain the baseband opportunity signal s without carrier modulation. n (t). When the carrier demodulation is sufficient, s n (t) has the following expression:

[0037] s n (t) = D (t) + n (t) (1)

[0038] Wherein, D(t) is the signal value of the baseband modulation code, which takes the value of -1 or 1; n(t) is the mixed noise of the propagation channel noise and the receiver thermal noise, which is Gaussian white noise in the model.

[0039] As an optional embodiment, the synchronization code sequence signal is slidingly correlated with the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal to obtain the synchronization code arrival time corresponding to each low-orbit satellite opportunity signal, including: for each low-orbit satellite opportunity signal, calculating the correlation value between the synchronization code sequence signal and the baseband opportunity signal corresponding to the low-orbit satellite opportunity signal at each sliding moment; if the correlation value reaches a maximum, determining the signal segment in the low-orbit satellite opportunity signal that has the highest overlap with the synchronization code sequence signal, corresponding to the position of the synchronization code in the baseband opportunity signal, and obtaining the synchronization code arrival time corresponding to the low-orbit satellite opportunity signal.

[0040] Optionally, generate a synchronization code sequence signal segment and s n (t) is used for sliding correlation. For each sliding moment, the correlation result is the sum of random -1 or 1 products. Therefore, when the correlation value reaches the maximum, it is the signal segment with the highest overlap with the synchronization code sequence in the baseband signal, which corresponds to the position of the synchronization code in the baseband signal. Based on this, the arrival time (Arrival Time) t of the synchronization code corresponding to the low-orbit satellite opportunity signal is obtained. a .

[0041] As an optional embodiment, the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals are differentiated to determine the pseudo-range difference observation amount between different low-orbit satellite opportunity signals, including: determining the time relationship between transmission and arrival of different synchronization codes; differentiating the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals according to the time relationship between transmission and arrival of different synchronization codes, and calculating the propagation time difference between different low-orbit satellite opportunity signals; and obtaining the pseudo-range difference observation amount between different low-orbit satellite opportunity signals based on the propagation time difference.

[0042] Optionally, based on the time period of synchronization code broadcasting, the synchronization codes in two different low-orbit satellite opportunity signals are set to synchronization code 1 and synchronization code 2, and the transmission time difference between the two is the time period T 0 According to the relationship between the transmission and arrival time of different synchronization codes, the arrival time of synchronization code 1 and synchronization code 2 is differentiated, and the calculation expression is as follows:

[0043] t a2 -t a1 =N·T 0 +t d2 -t d1 (N∈N * ) (2)

[0044] Assume that the propagation time difference Δt d =t d2 -t d1 , the time period of synchronization code broadcasting is T 0 It is much longer than the signal propagation time, and it is easy to solve N to eliminate it. The calculation expression is as follows:

[0045] Δt d =t a2 -t a1 -N·T 0 (N∈N * ) (3)

[0046] Furthermore, the propagation time difference is used to obtain the pseudo-range difference observation between different signal segments.

[0047] As an optional embodiment, obtaining a pseudorange difference observation amount between different low-orbit satellite opportunity signals based on the propagation time difference includes: obtaining the propagation speed of the low-orbit satellite opportunity signal in space; and calculating the pseudorange difference observation amount between different low-orbit satellite opportunity signals according to the propagation time difference and the propagation speed of the low-orbit satellite opportunity signal in space.

[0048] Optionally, the calculation expression used to calculate the pseudo-range difference observation quantity between different low-orbit satellite opportunity signals is as follows: , c is the propagation speed of electromagnetic waves in space.

[0049] Δρ=c·Δt d (4)

[0050] Where Δρ represents the pseudorange difference between different LEO opportunity signals; c represents the propagation speed of LEO opportunity signals in space; Δt d Represents the propagation time difference between different low-orbit satellite opportunity signals.

[0051] The complete message format of the low-orbit satellite opportunity signal is unknown, and the ranging information cannot be obtained by demodulating the navigation message. However, the signal contains a baseband data sequence with modulation information and a known format. This data sequence only lasts for a short period of time. The receiver can use this signal to obtain synchronization time. This baseband data sequence is called a synchronization code.

[0052] Figure 2 A schematic diagram of the time relationship between the transmission and arrival of different synchronization codes of a low-orbit satellite opportunity signal provided by an embodiment of the present invention, such as Figure 2 As shown in the figure, the low-orbit satellite broadcasts synchronization codes at fixed time intervals. The satellite segment signal transmission and the receiver end signal arrival are respectively displayed on the time axis. The time relationship between the transmission and arrival of different synchronization codes is as follows:

[0053] t sj -t si =N·T 0 (i,j,N∈N * ,j>i) (5)

[0054] t ai =t si +t di (6)

[0055] Among them, T 0 The time period for transmitting synchronization code of low-orbit satellite; t si is the transmission time of synchronization code i; t ai is the arrival time of synchronization code i; t di is the propagation time of synchronization code i; t sj is the transmission time of synchronization code j; t aj is the arrival time of synchronization code j; t dj is the propagation time of synchronization code j; N is a positive integer; N * is a set of positive integers.

[0056] Example 2

[0057] The invention provides a processing system for low-orbit satellite opportunity signal pseudo-range difference observation quantities. Figure 3 A schematic diagram of a processing system for low-orbit satellite opportunity signal pseudo-range difference observations provided by an embodiment of the present invention, such as Figure 3As shown, the processing system of the low-orbit satellite opportunity signal pseudo-range difference observation includes: a first processing module 302, a second processing module 304, a third processing module 306 and a fourth processing module 308. The processing system of the low-orbit satellite opportunity signal pseudo-range difference observation is described in detail below.

[0058] A first processing module 302 is used to receive multiple low-orbit satellite opportunity signals and obtain a carrier with the same frequency as each low-orbit satellite opportunity signal;

[0059] The second processing module 304 is connected to the first processing module 302, and is used to perform carrier demodulation on the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal;

[0060] The third processing module 306 is connected to the second processing module 304, and is used to obtain a synchronization code sequence signal, and slide-correlate the synchronization code sequence signal with the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, to obtain the synchronization code arrival time corresponding to each low-orbit satellite opportunity signal;

[0061] The fourth processing module 308 is connected to the third processing module 306, and is used to differentiate the arrival times of the synchronization codes corresponding to different low-orbit satellite opportunity signals to determine the pseudo-range difference observations between different low-orbit satellite opportunity signals.

[0062] In an embodiment of the present invention, the processing system of the pseudo-range difference observation of the low-orbit satellite opportunity signal adopts the method of receiving multiple low-orbit satellite opportunity signals and obtaining a carrier with the same frequency as each low-orbit satellite opportunity signal; based on the carrier corresponding to each low-orbit satellite opportunity signal, the corresponding low-orbit satellite opportunity signal is carrier-demodulated to obtain the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal; obtaining a synchronization code sequence signal, and slidingly correlating the synchronization code sequence signal with the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, respectively, to obtain the synchronization code arrival time corresponding to each low-orbit satellite opportunity signal; differentiating the synchronization code arrival times corresponding to different low-orbit satellite opportunity signals, and determining the pseudo-range difference observation between different low-orbit satellite opportunity signals, thereby solving the technical problem in the related art that the low-orbit satellite opportunity signal cannot be fully utilized due to the unknown navigation message format of the low-orbit satellite opportunity signal, and achieving the technical effect of overcoming the problem of the unknown navigation message format of the low-orbit satellite opportunity signal, obtaining available ranging information, and realizing more full utilization of the low-orbit satellite opportunity signal.

[0063] It should be noted here that the above-mentioned first processing module 302, second processing module 304, third processing module 306 and fourth processing module 308 correspond to steps S102 to S108 in the method embodiment, and the examples and application scenarios implemented by the above-mentioned modules are the same as those of the corresponding steps, but are not limited to the contents disclosed in the above-mentioned method embodiment.

[0064] Furthermore, the above-mentioned first processing module 302 includes: a first acquisition unit, used to convert each low-orbit satellite opportunity signal from the time domain to the frequency domain, and obtain the frequency of each low-orbit satellite opportunity signal; a generation unit, used to generate a carrier corresponding to each low-orbit satellite opportunity signal according to the frequency of each low-orbit satellite opportunity signal, wherein the carrier corresponding to each low-orbit satellite opportunity signal has the same frequency as each low-orbit satellite opportunity signal.

[0065] Furthermore, the second processing module 304 includes: a second acquisition unit, used to correlate the carrier corresponding to each low-orbit satellite opportunity signal with the corresponding low-orbit satellite opportunity signal, and obtain the baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, wherein the baseband opportunity signal includes the signal value of the baseband modulation code, the mixed noise of the propagation channel noise and the receiver thermal noise.

[0066] Furthermore, the third processing module 306 includes: a first calculation unit, for calculating the correlation value between the synchronization code sequence signal and the baseband opportunity signal corresponding to the low-orbit satellite opportunity signal at each sliding moment for each low-orbit satellite opportunity signal; and a third acquisition unit, for determining the signal segment in the low-orbit satellite opportunity signal with the highest degree of overlap with the synchronization code sequence signal, corresponding to the position of the synchronization code in the baseband opportunity signal, if the correlation value reaches a maximum, and obtaining the synchronization code arrival time corresponding to the low-orbit satellite opportunity signal.

[0067] Furthermore, the fourth processing module 308 includes: a determination unit, used to determine the time relationship between transmission and arrival of different synchronization codes; a second calculation unit, used to differentiate the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals according to the time relationship between transmission and arrival of different synchronization codes, and calculate the propagation time difference between different low-orbit satellite opportunity signals; and a fourth acquisition unit, used to acquire the pseudo-range difference observation value between different low-orbit satellite opportunity signals based on the propagation time difference.

[0068] Furthermore, the fourth acquisition unit includes: an acquisition subunit, used to acquire the propagation speed of the low-orbit satellite opportunity signal in space; and a calculation subunit, used to calculate the pseudo-range difference observation value between different low-orbit satellite opportunity signals based on the propagation time difference and the propagation speed of the low-orbit satellite opportunity signal in space.

[0069] Furthermore, the expression of the time relationship between the transmission and arrival of different synchronization codes is as follows:

[0070] t sj -t si =N·T 0 (i,j,N∈N * ,j>i),t ai =t si +t di ; Among them, T 0 The time period for transmitting synchronization code of low-orbit satellite; t si is the transmission time of synchronization code i; t ai is the arrival time of synchronization code i; t di is the propagation time of synchronization code i; t sj is the transmission time of synchronization code j; t aj is the arrival time of synchronization code j; t dj is the propagation time of synchronization code j; N is a positive integer; N * is a set of positive integers.

[0071] Example 3

[0072] The present invention provides an electronic device, comprising: a processor, and a memory for storing a program, wherein the program comprises instructions, and when the instructions are executed by the processor, the processor executes a method for processing pseudorange difference observations of a low-orbit satellite opportunity signal described in the embodiment.

[0073] refer to Figure 4 , a block diagram of an electronic device that can be used as a server or client of an embodiment of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. Electronic devices are intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. Electronic devices can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0074] like Figure 4As shown, the electronic device includes a computing unit 401, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 402 or a computer program loaded from a storage unit 408 into a random access memory (RAM) 403. In RAM 403, various programs and data required for the operation of the electronic device can also be stored. The computing unit 401, ROM 402, and RAM 403 are connected to each other via a bus 404. An input / output (I / O) interface 405 is also connected to the bus 404.

[0075] Multiple components in the electronic device are connected to the I / O interface 405, including: an input unit 406, an output unit 407, a storage unit 408, and a communication unit 409. The input unit 406 can be any type of device that can input information to the electronic device, and the input unit 406 can receive input digital or character information, and generate key signal input related to user settings and / or function control of the electronic device. The output unit 407 can be any type of device that can present information, and can include but is not limited to a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 408 can include but is not limited to a disk, an optical disk. The communication unit 409 allows the electronic device to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks, and can include but is not limited to a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0076] The computing unit 401 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 401 include, but are not limited to, a CPU, a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 401 performs the various methods and processes described above. For example, in some embodiments, the method embodiments of the present invention may be implemented as a computer program, which is tangibly contained in a machine-readable medium, such as a storage unit 408. In some embodiments, part or all of the computer program may be loaded and / or installed on an electronic device via ROM 402 and / or communication unit 409. In some embodiments, the computing unit 401 may be configured to perform the method described above in Example 1 by any other appropriate means (e.g., by means of firmware).

[0077] Example 4

[0078] The present invention provides a computer-readable storage medium, characterized in that the computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method for processing the pseudorange difference observation amount of the low-orbit satellite opportunity signal mentioned in Example 1.

[0079] The embodiment of the present invention provides a computer-readable storage medium, which stores computer instructions, and the computer instructions are used to make the computer execute a relative positioning method of embodiment 1. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM), a random access memory (RAM), a flash memory (FlashMemory), a hard disk (HDD) or a solid-state drive (SSD), etc.; the storage medium can also include a combination of the above-mentioned types of memory.

[0080] It should be noted that the term "including" and its variations used in the embodiments of the present invention are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". The modifications of "one" and "multiple" mentioned in the embodiments of the present invention are illustrative rather than restrictive. Those skilled in the art should understand that unless the context clearly indicates otherwise, it should be understood as "one or more".

[0081] The various steps described in the method implementation methods provided in the embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method implementation methods may include additional steps and / or omit the steps shown. The scope of protection of the present invention is not limited in this respect.

[0082] The term "embodiment" in this specification refers to specific features, structures or characteristics described in conjunction with the embodiment that can be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. The various embodiments in this specification are described in a related manner, and the same or similar parts between the various embodiments refer to each other. In particular, for the device, equipment, and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts refer to the partial description of the method embodiment.

[0083] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A method for processing pseudo-range difference observations of low-orbit satellite opportunity signals, characterized in that: The steps include: Step S102: receiving a plurality of low-orbit satellite opportunity signals, and acquiring a carrier having the same frequency as each of the low-orbit satellite opportunity signals; Step S104: performing carrier demodulation on the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal; Step S106: Acquire a synchronization code sequence signal, and perform sliding correlation on the synchronization code sequence signal and the baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, to obtain a synchronization code arrival time corresponding to each of the low-orbit satellite opportunity signals; Step S108: Differentiate the arrival times of synchronization codes corresponding to different LEO satellite opportunity signals to determine the observed pseudo-range differences between the different LEO satellite opportunity signals.

2. The method for processing pseudo-range difference observations of low-orbit satellite opportunity signals according to claim 1, characterized in that: Acquiring a carrier wave having the same frequency as each of the low-orbit satellite opportunity signals comprises the following steps: Convert each of the low-orbit satellite opportunity signals from the time domain to the frequency domain to obtain the frequency of each of the low-orbit satellite opportunity signals; A carrier wave corresponding to each of the low-orbit satellite opportunity signals is generated according to the frequency of each of the low-orbit satellite opportunity signals, wherein the carrier wave corresponding to each of the low-orbit satellite opportunity signals has the same frequency as each of the low-orbit satellite opportunity signals.

3. The method for processing pseudo-range difference observations of low-orbit satellite opportunity signals according to claim 1, characterized in that: Carrier demodulating the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal, including: The carrier corresponding to each of the low-orbit satellite opportunity signals is correlated with the corresponding low-orbit satellite opportunity signals to obtain a baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, wherein the baseband opportunity signal includes a signal value of a baseband modulation code, a mixed noise of a propagation channel noise and a receiver thermal noise.

4. The method for processing pseudo-range difference observations of low-orbit satellite opportunity signals according to claim 1, characterized in that: The synchronization code sequence signal is respectively sliding correlated with the baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals to obtain the synchronization code arrival time corresponding to each of the low-orbit satellite opportunity signals, comprising the following steps: For each of the low-orbit satellite opportunity signals, calculating, at each sliding moment, a correlation value between the synchronization code sequence signal and a baseband opportunity signal corresponding to the low-orbit satellite opportunity signal; If the correlation value reaches the maximum, the signal segment in the low-orbit satellite opportunity signal that has the highest overlap with the synchronization code sequence signal is determined, corresponding to the position of the synchronization code in the baseband opportunity signal, and the synchronization code arrival time corresponding to the low-orbit satellite opportunity signal is obtained.

5. The method for processing pseudo-range difference observations of low-orbit satellite opportunity signals according to claim 1, characterized in that: Differentiating the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals to determine the pseudo-range difference observations between the different low-orbit satellite opportunity signals comprises the following steps: Determine the time relationship between the transmission and arrival of different synchronization codes; Differentiating the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals according to the time relationship between the transmission and arrival of different synchronization codes, and calculating the propagation time difference between different low-orbit satellite opportunity signals; Based on the propagation time difference, a pseudorange difference observation value between different low-orbit satellite opportunity signals is obtained.

6. The method for processing pseudo-range difference observations of low-orbit satellite opportunity signals according to claim 5, characterized in that: Acquiring pseudorange difference observations between different low-orbit satellite opportunity signals based on the propagation time difference comprises the following steps: Obtaining the propagation speed of the low-orbit satellite opportunity signal in space; According to the propagation time difference and the propagation speed of the low-orbit satellite opportunity signal in space, the pseudo-range difference observation amount between different low-orbit satellite opportunity signals is calculated.

7. The method according to claim 5, characterized in that The expression of the time relationship between the transmission and arrival of different synchronization codes is as follows: t sj -t si =N·T0(i,j,N∈N * ,j>i) t ai =t si +t di Among them, T0 is the time period of the low-orbit satellite transmitting the synchronization code; t si is the transmission time of synchronization code i; t ai is the arrival time of synchronization code i; t di is the propagation time of synchronization code i; t sj is the transmission time of synchronization code j; t aj is the arrival time of synchronization code j; t dj is the propagation time of synchronization code j; N is a positive integer; N * is a set of positive integers.

8. A processing system for pseudo-range difference observations of low-orbit satellite opportunity signals, characterized in that: include: A first processing module (402) is used to receive a plurality of low-orbit satellite opportunity signals and obtain a carrier having the same frequency as each of the low-orbit satellite opportunity signals; A second processing module (404) is used to perform carrier demodulation on the corresponding low-orbit satellite opportunity signal based on the carrier corresponding to each low-orbit satellite opportunity signal to obtain a baseband opportunity signal corresponding to each low-orbit satellite opportunity signal; A third processing module (406) is used to obtain a synchronization code sequence signal, and perform sliding correlation between the synchronization code sequence signal and a baseband opportunity signal corresponding to each of the low-orbit satellite opportunity signals, to obtain a synchronization code arrival time corresponding to each of the low-orbit satellite opportunity signals; The fourth processing module (408) is used to differentiate the arrival times of synchronization codes corresponding to different low-orbit satellite opportunity signals to determine the pseudo-range difference observations between different low-orbit satellite opportunity signals.

9. An electronic device, comprising: A processor, and a memory for storing a program, characterized in that the program includes instructions, which, when executed by the processor, cause the processor to execute a method for processing pseudorange difference observations of low-orbit satellite opportunity signals according to any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable the computer to execute the method for processing low-orbit satellite opportunity signal pseudo-range difference observations as described in any one of claims 1 to 7.

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