Navigation signal processing method and device, equipment and storage medium

Abstract

The invention relates to the technical field of satellite navigation, and discloses a navigation signal processing method, device and equipment and a storage medium, and the method comprises the following steps: arranging a plurality of completely same baseband processing modules in parallel; obtaining a tracking tolerance based on a difference condition among the plurality of tracking results; when the tracking tolerance belongs to a preset tolerance threshold range, outputting any tracking result as an effective navigation signal; and when the tracking tolerance does not belong to the tolerance threshold range, triggering a preset verification failure alarm. The device, the equipment and the storage medium all correspond to the method. According to the invention, rapid and steady signal acquisition and precise tracking can be realized under the Doppler dynamic state and the carrier dynamic state of a low orbit, signal processing errors caused by the single event effect can be detected, isolated, corrected or tolerated in real time, the continuity and the reliability of navigation and positioning services are ensured, and the requirement of long-term in-orbit autonomous operation of a low-orbit satellite is met.

Description

Technical Field

[0001] This application relates to the field of satellite navigation technology, specifically a navigation signal processing method, apparatus, device, and storage medium. Background Technology

[0002] With the explosive growth of applications such as low Earth orbit (LEO) mega-constellations, remote sensing satellites, and scientific experimental satellites, the demand for autonomous, real-time, and high-precision navigation and orbit determination on LEO satellite platforms is becoming increasingly urgent. Utilizing navigation signals from Global Navigation Satellite Systems (GNSS) for real-time orbit determination and attitude assessment in orbit has become a key technology for achieving high-precision autonomous operation of LEO satellites. However, compared to terrestrial or medium-to-high Earth orbit environments, the LEO environment presents extremely stringent challenges to GNSS receivers in terms of dynamics and space radiation.

[0003] Low-Earth orbit (LEO) satellites travel at extremely high speeds, causing the received GNSS navigation signals to experience drastic Doppler shifts and rapid rates of change. Simultaneously, the satellite's high-speed motion, attitude maneuvers, and potential vibrations introduce significant dynamic acceleration and jerk. This high-dynamic characteristic makes signal acquisition difficult and seriously threatens the stability of the signal tracking loop, necessitating a wider frequency search range and faster search speed in applications.

[0004] Meanwhile, during satellite operation, it is exposed to a significantly higher level of space radiation than the Earth's surface. Space radiation effects, especially single-event effects, pose a serious threat to the digital and analog circuits inside the receiver, causing navigation data errors, loop lockouts, and even complete receiver malfunctions, severely compromising the reliability and safety of the satellite mission. For the radiation problems caused by low-Earth orbit, high-dynamic, multi-system, and multi-frequency navigation signals, traditional radiation-resistant designs mainly rely on process-level hardening or device-level screening, which are extremely costly, and the performance of available devices often lags behind that of application-specific integrated circuits (ASICs). Software fault tolerance primarily protects memory and data paths, but its protection capability for signal processing loops with extremely high real-time requirements, such as tracking loop state control and numerically controlled oscillator (NCO) control, is limited, and it still cannot completely resist the disruption of signal tracking loop continuity caused by space radiation-induced disturbances such as single-event transients (SET) or single-event functional interruptions (SEFI). Under high dynamic pressure, GNSS receivers are even more sensitive to transient disturbances caused by radiation.

[0005] In summary, there is an urgent need for a new navigation signal processing technology to meet the requirements of processing low-orbit, high-dynamic, multi-system, and multi-frequency navigation signals, while also being cost-effective. Summary of the Invention

[0006] The purpose of this application is to provide a navigation signal processing method, apparatus, device, and storage medium to solve the technical problem in the prior art of being unable to process low-orbit, high-dynamic, multi-system, and multi-frequency navigation signals at low cost.

[0007] To achieve the above objectives, this application discloses a navigation signal processing method applicable to processing low-orbit, high-dynamic, multi-system, multi-frequency navigation signals. The method includes: Multiple identical baseband processing modules are set up in parallel, and the multiple baseband processing modules are configured to start synchronously and perform the same processing flow on the same input initial navigation signal to output multiple tracking results; The tracking tolerance is obtained based on the differences between multiple tracking results; When the tracking tolerance is within the preset tolerance threshold range, any tracking result is output as a valid navigation signal; when the tracking tolerance is not within the tolerance threshold range, a preset verification failure alarm is triggered.

[0008] Preferably, the baseband processing module has multiple capture channels arranged in parallel. Each of the acquisition channels receives the initial navigation signal and performs coherent integration with the pre-generated pseudocode; Extract the maximum output value of the correlator in each of the capture channels, store the maximum output value that is greater than the preset capture threshold and its corresponding communication information, and define it as peak data; The peak data is read and error correction code verification is performed. The peak data that passes the error correction code verification is defined as a valid acquisition result. The valid acquisition result includes at least the code phase and the initial Doppler value.

[0009] Preferably, the baseband processing module is provided with multiple independent tracking channels, and each tracking channel is equipped with a discriminator. The tracking channel receives the assigned valid acquisition result, performs carrier loop tracking and code loop tracking on the valid acquisition result, and outputs a continuous error value based on the discriminator, the continuous error value including frequency error and phase error; The continuous error value is quantized into a discrete value with finite precision. A majority vote is performed on the discrete values ​​generated by multiple correlators in the same carrier loop or code loop to obtain the loop error estimate. The loop error estimate is then input into a preset loop filter, and the tracking result is output.

[0010] Preferably, the verification failure alarm includes: Based on a preset selection strategy, one of the tracking results is selected, marked as low confidence, and then output. The baseband processing module that triggered the verification failure alarm is reset and reported.

[0011] Preferably, the capture channel includes direct capture and traction capture, and the direct capture and traction capture are in competition, with either capture method completing the capture and locking the capture.

[0012] Preferably, the selection strategy is as follows: The tracking results are compared based on historical application data or simulation data, and the tracking results with small differences are selected for output and marked as low confidence; wherein, the simulation data is obtained in advance based on the satellite's planned orbit by a ground simulation system.

[0013] Preferably, when entering the tracking channel from the capture channel, the Doppler estimation method is open-loop estimation.

[0014] To achieve the above objectives, this application also discloses a navigation signal processing apparatus that applies the navigation signal processing method described above. The apparatus includes: A redundancy setting module is used to set up multiple identical baseband processing modules in parallel. The multiple baseband processing modules are configured to start synchronously and perform the same processing flow on the same input initial navigation signal to output multiple tracking results. The tolerance processing module is used to obtain the tracking tolerance based on the differences between multiple tracking results; The navigation analysis module is used to output any of the tracking results as a valid navigation signal when the tracking tolerance is within a preset tolerance threshold range; and to trigger a preset verification failure alarm when the tracking tolerance is not within the tolerance threshold range.

[0015] To achieve the above objectives, this application also discloses an apparatus including at least one processor, at least one memory, and a data bus; The processor and the memory communicate with each other via the data bus; The memory stores program instructions that can be executed by the processor, which invokes the program instructions to execute the navigation signal processing method described above.

[0016] To achieve the above objectives, this application also discloses a storage medium storing a computer program, characterized in that the computer program, when executed by a processor, implements the navigation signal processing method as described above.

[0017] Beneficial effects: The navigation signal processing method, apparatus, equipment and storage medium of this application can achieve fast and robust signal acquisition and precise tracking under low-Earth orbit Doppler dynamics and carrier dynamics, and can detect, isolate, correct or tolerate signal processing errors caused by single-event effects in real time, ensuring the continuity and reliability of navigation and positioning services, and meeting the needs of low-Earth orbit satellites for long-term autonomous operation in orbit. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 A flowchart illustrating the navigation signal processing method provided in an embodiment of this application; Figure 2 A flowchart illustrating the implementation process of the baseband processing module provided in this application embodiment; Figure 3 This is a structural block diagram of the navigation signal processing device provided in an embodiment of this application.

[0020] The implementation, functional features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0021] The technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0022] In this document, the term "comprising" is intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0023] To achieve low-cost, radiation-resistant processing of low-Earth orbit, high-dynamic, multi-system, multi-frequency navigation signals, thereby providing robust navigation data for satellite navigation, this embodiment provides a navigation signal processing method. (Refer to...) Figure 1 , Figure 1This is a flowchart of the navigation signal processing method provided in this embodiment.

[0024] like Figure 1 As shown, this embodiment discloses a navigation signal processing method applicable to processing low-orbit, high-dynamic, multi-system, multi-frequency navigation signals. The method includes the following steps: S1: Multiple identical baseband processing modules are set up in parallel. These modules are configured to start synchronously and perform the same processing flow on the same initial navigation signal to output multiple tracking results. S2: The tracking tolerance is obtained based on the differences between multiple tracking results; S3: When the tracking tolerance is within the preset tolerance threshold range, output any tracking result as a valid navigation signal; when the tracking tolerance is not within the tolerance threshold range, trigger a preset verification failure alarm.

[0025] In one specific implementation, this embodiment synchronously inputs multiple identical baseband processing modules with redundant design to process the navigation signal presented as an intermediate frequency signal in parallel.

[0026] Specifically, the baseband processing module has multiple capture channels set up in parallel; Each acquisition channel receives the initial navigation signal and performs coherent integration with the pre-generated pseudocode; Extract the maximum output value of the correlator in each capture channel, store the maximum output value that is greater than the preset capture threshold and its corresponding communication information, and define it as peak data; The peak data is checked by error correction code. The peak data that passes the error correction code check is defined as the valid acquisition result. The valid acquisition result includes at least the code phase and the initial value of Doppler.

[0027] Specifically, the baseband processing module has multiple independent tracking channels, and each tracking channel is equipped with a discriminator. The tracking channel receives the assigned valid acquisition result, performs carrier loop tracking and code loop tracking on the valid acquisition result, and outputs continuous error values ​​based on the discriminator. The continuous error values ​​include frequency error and phase error. The continuous error value is quantized into a discrete value with finite precision. A majority vote is performed on the discrete values ​​generated by multiple correlators in the same carrier loop or code loop to obtain the loop error estimate. The loop error estimate is then input into a preset loop filter, and the tracking result is output.

[0028] In one specific implementation, within the baseband processing module, the navigation signal first enters parallel acquisition channels for rapid acquisition across multiple systems and frequencies. After acquisition, it is transferred to multiple independent tracking channels, where carrier loop and code loop processing are performed separately. The resulting loop error is quantized to control the error, and then smoothed by loop filtering to form a closed-loop tracking control (NCO). Finally, the independent tracking results output by multiple baseband processing modules undergo real-time consistency cross-checking, and the validity of the results is determined based on a preset tolerance.

[0029] The navigation signal processing method in this embodiment can achieve fast and robust signal acquisition and precise tracking under low-Earth orbit Doppler dynamics and carrier dynamics. It can also detect, isolate, correct or tolerate signal processing errors caused by single-event effects in real time, ensuring the continuity and reliability of navigation and positioning services and meeting the needs of low-Earth orbit satellites for long-term autonomous operation in orbit.

[0030] Specifically, verification failure alarms include: Based on a preset selection strategy, a tracking result is selected and marked as low confidence before being output; The baseband processing module that triggered the verification failure alarm is reset and reported.

[0031] Specifically, the capture methods of the capture channel include direct capture and towing capture, and direct capture and towing capture are in competition with each other. Either capture method can complete the capture and lock capture.

[0032] Specifically, the selection strategy is as follows: The tracking results are compared based on historical application data or simulation data. Tracking results with small differences are selected for output and marked as low confidence. The simulation data is obtained in advance based on the satellite's planned orbit by a ground simulation system.

[0033] Specifically, when moving from the capture channel to the tracking channel, the Doppler estimation method is open-loop estimation.

[0034] In the specific application of this embodiment, the intermediate frequency signal is simultaneously input to two identical baseband processing modules BB0 and BB1. The two baseband processing modules start synchronously and perform the same processing operations. For example... Figure 2 As shown, taking the processing of the baseband processing module BB0 as an example, we illustrate a specific implementation step of the navigation signal processing method in this embodiment, including: A1: Enters multiple parallel acquisition channels within the baseband processing module BB0. Within a single acquisition channel, the signal is coherently integrated with the locally generated pseudocode to find the maximum value of the correlator output for each channel. The correlator peak data exceeding the acquisition threshold is stored in the memory.

[0035] To enable the processing of navigation signals from multiple systems and frequencies, a corresponding compatibility acquisition mechanism is designed. This compatibility acquisition employs two methods: direct acquisition and towing acquisition. The direct acquisition module and the towing acquisition module are relatively independent, but they compete under acquisition scheduling management. Once one method completes acquisition, the channel status is locked to prevent the other method from continuing to acquire signals and repeatedly uploading them to the satellite. This achieves highly compatible and efficient multi-system, multi-frequency acquisition.

[0036] A2: Read the selected peak data, such as code phase and Doppler, from the acquisition result memory, perform error correction code verification, and ensure that no errors occurred during the storage / retrieval of the acquisition information. Assign the valid acquisition results, such as code phase and initial Doppler values, verified by ECC to multiple independent tracking channels, and perform carrier and code loop tracking in the assigned tracking channels.

[0037] A3: Quantize the continuous error values ​​(frequency error, phase error) output by the discriminator of each tracking channel (carrier ring and code ring) into discrete values ​​with finite precision. Perform majority voting on the quantized error values ​​generated by multiple correlator branches in the same loop (carrier ring or code ring) to obtain the loop error estimate. Input the quantized error value into the loop filter.

[0038] A4: Baseband processing module BB0 and baseband processing module BB1 ​​will independently output their respective tracking results and compare them with each other.

[0039] This comparison is as follows: If the results are consistent within the preset tolerance range, the results are considered valid and reliable, and one of them can be selected as the final output.

[0040] If the results exceed the tolerance range and show significant differences, a verification failure alarm is triggered. Based on the preset strategy, one of the results that looks more reliable is selected for output (but marked as low confidence). The module with large differences is reset and reported.

[0041] In one embodiment, two baseband processing modules, BB0 and BB1, are used to perform the exact same processing operations, achieving hardware and software processing redundancy. In practical applications, the number of baseband processing modules can be increased as needed.

[0042] In one embodiment, in A2, the correlator peak value exceeding the preset capture threshold, including its corresponding code phase offset, Doppler frequency offset, channel identifier, and related energy value, is stored in a dedicated capture result memory.

[0043] In one embodiment, in A2, direct acquisition employs a scheme combining a partially matched filter (PMF) and a fast Fourier transform (FFT). Towing acquisition uses an already acquired frequency point of the same satellite to tow another unacquired frequency point. This leverages the fact that the two frequencies belong to the same satellite, their signal transmission times are identical, and their carrier Doppler frequencies exhibit a certain proportional relationship. When using towing acquisition, the towing frequency point is the reference frequency point, and the towed frequency point is the towed frequency point. Among the many frequency points in the same system, the reference frequency point does not necessarily need to be fixed; multiple frequency points can tow each other. When the reference frequency point channel is in different synchronization states, the towed frequency point also needs to be set to different states; after the reference frequency point channel completes frame synchronization, the towed frequency point can also be directly set to the frame synchronization state, completing the acquisition and tracking of the towed frequency point in one step. Based on this, adaptability is achieved for navigation signals with large and rapidly changing Doppler frequency shifts.

[0044] In one embodiment, the Doppler estimation method uses an open-loop estimation calculated based on the following formula: in, , , It is the first The result of the coherent integral. , It is the first The result of the coherent integral. For frequency difference estimation, For the coherent integration time.

[0045] It should be noted that in this embodiment, carrier loop and code loop tracking are performed in the allocated tracking channel, and frequency and phase discrimination are performed in a conventional manner to estimate and track the carrier frequency deviation and code phase deviation of the signal.

[0046] In one embodiment, in A4, the continuous error values ​​can be discretized to obtain the quantization error at the current moment, and the latest L continuous quantization error values ​​are saved. The current L quantization error values ​​in the buffer are statistically analyzed, and majority voting, weighted averaging, etc. can be used. The voting result is input to the loop filter, and the filtered output control quantity is applied to the corresponding voltage-controlled oscillator (VCO). The output phase / frequency / code phase is updated according to the control quantity.

[0047] In one embodiment, in A5, when the results from the two baseband processing modules are inconsistent, the output results are compared based on historical application data or simulation data. The output with the smaller difference is selected and marked as low confidence for reference by subsequent solution models. The simulation data can be obtained in advance by a ground simulation system based on the satellite's planned orbit.

[0048] like Figure 3As shown, this embodiment also discloses a navigation signal processing apparatus, which applies the navigation signal processing method described above. The apparatus includes: The redundancy setting module is used to set up multiple identical baseband processing modules in parallel. The multiple baseband processing modules are configured to start synchronously and perform the same processing flow on the same input initial navigation signal to output multiple tracking results. The tolerance processing module is used to obtain the tracking tolerance based on the differences between multiple tracking results; The navigation analysis module is used to output any tracking result as a valid navigation signal when the tracking tolerance is within the preset tolerance threshold range; and to trigger a preset verification failure alarm when the tracking tolerance is not within the tolerance threshold range.

[0049] This embodiment also discloses a device, including at least one processor, at least one memory, and a data bus; The processor and memory communicate with each other via a data bus; The memory stores program instructions that can be executed by the processor, which calls the program instructions to execute the navigation signal processing method described above.

[0050] This embodiment also discloses a storage medium on which a computer program is stored, and when the computer program is executed by a processor, it implements the navigation signal processing method described above.

[0051] It should be noted that the navigation signal processing device, equipment, and storage medium of this embodiment correspond to the aforementioned navigation signal processing method. Therefore, any content not specifically described in the navigation signal processing device, equipment, and storage medium of this embodiment, including but not limited to functional definitions, working principles, and technical effects, can be referred to the description in the aforementioned navigation signal processing method, and will not be repeated here.

[0052] In summary, the navigation signal processing method, apparatus, device, and storage medium of this embodiment can achieve rapid and robust signal acquisition and precise tracking under low-Earth orbit Doppler dynamics and carrier dynamics. It can also detect, isolate, correct, or tolerate signal processing errors caused by single-event effects in real time, ensuring the continuity and reliability of navigation and positioning services. This meets the need for low-cost response to the long-term autonomous operation of low-Earth orbit satellites, enables the processing of high-dynamic, multi-system, and multi-frequency navigation signals in low-Earth orbit, and meets the radiation resistance requirements for low-Earth orbit operation.

[0053] In the embodiments provided in this application, it should be understood that the embodiments described herein can be implemented in hardware, software, firmware, middleware, code, or any suitable combination thereof. For hardware implementation, the processor may be implemented in one or more of the following: application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field-programmable gate arrays (FPGAs), processors, controllers, microcontrollers, microprocessors, other electronic units designed to implement the functions described herein, or combinations thereof. For software implementation, some or all of the processes of the embodiments may be performed by a computer program instructing the associated hardware. During implementation, the program may be stored in a computer-readable storage medium or transmitted as one or more instructions or code on a computer-readable storage medium. Computer-readable storage media include computer storage media and communication media, wherein communication media include any medium that facilitates the transmission of a computer program from one place to another. Storage media may be any available medium accessible to a computer. Computer-readable storage media may include, but are not limited to, RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code having the form of instructions or data structures and accessible to a computer.

[0054] Finally, it should be noted that the above description is only a preferred embodiment of this application and is not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A navigation signal processing method, characterized in that, This method is applicable to processing low-Earth orbit, high-dynamic, multi-system, multi-frequency navigation signals, and includes: Multiple identical baseband processing modules are set up in parallel, and the multiple baseband processing modules are configured to start synchronously and perform the same processing flow on the same input initial navigation signal to output multiple tracking results; The tracking tolerance is obtained based on the differences between multiple tracking results; When the tracking tolerance is within the preset tolerance threshold range, any tracking result is output as a valid navigation signal; when the tracking tolerance is not within the tolerance threshold range, a preset verification failure alarm is triggered.

2. The navigation signal processing method as described in claim 1, characterized in that, The baseband processing module has multiple capture channels arranged in parallel. Each of the acquisition channels receives the initial navigation signal and performs coherent integration with the pre-generated pseudocode; Extract the maximum output value of the correlator in each of the capture channels, store the maximum output value that is greater than the preset capture threshold and its corresponding communication information, and define it as peak data; The peak data is read and the error correction code is verified. The peak data that passes the error correction code verification is defined as a valid acquisition result. The valid acquisition result includes at least the code phase and the initial Doppler value.

3. The navigation signal processing method as described in claim 2, characterized in that, The baseband processing module is equipped with multiple independent tracking channels, and each tracking channel is equipped with a discriminator. The tracking channel receives the assigned valid acquisition result, performs carrier loop tracking and code loop tracking on the valid acquisition result, and outputs a continuous error value based on the discriminator, the continuous error value including frequency error and phase error; The continuous error value is quantized into a discrete value with finite precision. A majority vote is performed on the discrete values ​​generated by multiple correlators in the same carrier loop or code loop to obtain the loop error estimate. The loop error estimate is then input into a preset loop filter, and the tracking result is output.

4. The navigation signal processing method as described in claim 1, characterized in that, The verification failure alarm includes: Based on a preset selection strategy, one of the tracking results is selected, marked as low confidence, and then output. The baseband processing module that triggered the verification failure alarm is reset and reported.

5. The navigation signal processing method as described in claim 2, characterized in that, The capture channel includes two capture methods: direct capture and traction capture. Direct capture and traction capture are in competition with each other. The capture channel locks the target when either capture method is completed.

6. The navigation signal processing method as described in claim 4, characterized in that, The selection strategy is as follows: The tracking results are compared based on historical application data or simulation data, and the tracking results with small differences are selected for output and marked as low confidence; wherein, the simulation data is obtained in advance based on the satellite's planned orbit by a ground simulation system.

7. The navigation signal processing method as described in claim 3, characterized in that, When entering the tracking channel from the capture channel, the Doppler is estimated using an open-loop estimation method.

8. A navigation signal processing apparatus, employing the navigation signal processing method as described in any one of claims 1-7, characterized in that, The device includes: A redundancy setting module is used to set up multiple identical baseband processing modules in parallel. The multiple baseband processing modules are configured to start synchronously and perform the same processing flow on the same input initial navigation signal to output multiple tracking results. The tolerance processing module is used to obtain the tracking tolerance based on the differences between multiple tracking results; The navigation analysis module is used to output any of the tracking results as a valid navigation signal when the tracking tolerance is within a preset tolerance threshold range; and to trigger a preset verification failure alarm when the tracking tolerance is not within the tolerance threshold range.

9. A device, characterized in that, Includes at least one processor, at least one memory, and a data bus; The processor and the memory communicate with each other via the data bus; The memory stores program instructions that can be executed by the processor, which invokes the program instructions to perform the navigation signal processing method according to any one of claims 1 to 7.

10. A storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the navigation signal processing method according to any one of claims 1 to 7.

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