Satellite signal tracking method and device, computer equipment and storage medium

Abstract

The embodiment of the invention discloses a satellite signal tracking method and device, computer equipment and a storage medium, and the method comprises the steps: obtaining the operation linear speed of a target satellite, and obtaining a target signal according to the operation linear speed and an included angle between the target satellite and a ground terminal at the current moment; calculating the radial speed of the target satellite relative to the ground terminal at the current moment; obtaining a pre-constructed Doppler frequency shift expression, establishing a drift trend estimator according to the Doppler frequency shift expression, and constructing a frequency shift predictor according to the drift trend estimator; calculating predicted frequency shift at the next moment according to the radial speed and the frequency shift predictor; and performing signal scanning on the target satellite according to the predicted frequency shift and a preset frequency scanning window. By applying the scheme provided by the embodiment of the invention, the stability of satellite signal tracking can be improved.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of satellite signal tracking, in particular to a satellite signal tracking method and device, computer equipment and a storage medium. BACKGROUND

[0002] With the rapid deployment of low earth orbit (LEO) satellite constellations such as Starlink and OneWeb, ground terminals need to stably track multiple high-speed moving satellite signals in a high dynamic environment. Due to the high speed of low earth orbit satellites, such as an average speed of about 7.5 km / s, and the short time of staying in the field of view, the tracking difficulty is great.

[0003] The known satellite signal tracking method is mainly a phased array antenna beam pointing control. This method needs to obtain satellite orbit parameters in real time and predict the motion model, and the algorithm complexity is high and the calculation time is long, which leads to serious satellite signal tracking lag and poor stability. Therefore, how to improve the stability of satellite signal tracking has become a technical problem to be solved. SUMMARY

[0004] The application provides a satellite signal tracking method, device, computer equipment and storage medium to improve the stability of satellite signal tracking. The specific technical solutions are as follows.

[0005] In the first aspect, the application embodiment provides a satellite signal tracking method, which is applied to a ground terminal, and the method comprises the following steps: Obtaining the running linear speed of a target satellite, calculating the radial speed of the target satellite relative to the ground terminal at the current time according to the running linear speed and the angle of the target satellite relative to the ground terminal at the current time; Obtaining a pre-constructed Doppler frequency shift expression, establishing a drift trend estimator according to the Doppler frequency shift expression, and constructing a frequency shift predictor according to the drift trend estimator; According to the radial speed and the frequency shift predictor, calculating the predicted frequency shift at the next time; According to the predicted frequency shift and a pre-set frequency scanning window, performing signal scanning on the target satellite.

[0006] As an implementation manner of the application embodiment, the step of establishing a drift trend estimator according to the Doppler frequency shift expression, and constructing a frequency shift predictor according to the drift trend estimator comprises the following steps: First-order difference is performed on the Doppler frequency shift expression to obtain a drift trend estimator; According to the Doppler frequency shift expression and the drift trend estimator, a frequency shift predictor is constructed.

[0007] As an implementation manner of an embodiment of the present application, the step of constructing a frequency shift predictor according to the Doppler frequency shift expression and the drift trend estimator includes: Construct the following frequency shift predictor: in, is the Doppler shift at the current moment, is the drift trend estimator, the is the predicted frequency shift at the next moment.

[0008] As an implementation of the embodiment of the present application, the method further includes: Acquiring signal parameters of the received signal; the signal parameters include at least carrier-to-noise ratio, phase change rate, and cross-correlation peak; Calculating a comprehensive error factor of the received signal based on the signal parameters; When the comprehensive error factor is greater than or equal to a preset threshold, the frequency shift values ​​of the most recent preset number of moments are counted, the frequency shift change value between every two adjacent moments is calculated based on each of the frequency shift values, and a frequency shift trend prediction model is obtained by fitting; A frequency scanning window center value is calculated according to the frequency shift change value and the frequency shift trend prediction model, and a signal scan is performed on the target satellite again according to the frequency scanning window center value and the frequency scanning window.

[0009] As an implementation manner of an embodiment of the present application, the step of calculating the comprehensive error factor of the received signal based on the signal parameter includes: Calculate the comprehensive error factor according to the following formula: : in, 、 、 All are pre-set weight coefficients; is the carrier-to-noise ratio, is the reference carrier-to-noise ratio, is the phase change rate, is the cross-correlation peak, is the ideal peak value.

[0010] As an implementation manner of an embodiment of the present application, the step of calculating the center value of the frequency scanning window according to the frequency shift change value and the frequency shift trend prediction model includes: Calculate the frequency scan window center value according to the following formula: : wherein, is the frequency shift trend prediction model, is the average of each of the frequency shift change values, is a preset feedback gain coefficient; wherein, , is a fitting coefficient, t is a time variable.

[0011] In a second aspect, an embodiment of the present application provides a satellite signal tracking device, the device being applied to a ground terminal, and the device comprising: a speed obtaining module, configured to obtain a running linear speed of a target satellite, and calculate a radial speed of the target satellite relative to the ground terminal at a current time according to the running linear speed and an angle of the target satellite relative to the ground terminal at the current time; a predictor constructing module, configured to obtain a Doppler shift expression constructed in advance, establish a drift trend estimator according to the Doppler shift expression, and construct a frequency shift predictor according to the drift trend estimator; a frequency shift prediction module, configured to calculate a predicted frequency shift at a next time according to the radial speed and the frequency shift predictor; a signal tracking module, configured to perform signal scanning on the target satellite according to the predicted frequency shift and a preset frequency scanning window.

[0012] As an implementation manner of the embodiment of the present application, the predictor constructing module is specifically configured to: perform first-order differentiation on the Doppler shift expression to obtain the drift trend estimator; construct the frequency shift predictor according to the Doppler shift expression and the drift trend estimator.

[0013] As an implementation manner of the embodiment of the present application, the predictor constructing module is specifically configured to construct the following frequency shift predictor: wherein, is a Doppler shift at a current time, is the drift trend estimator, and the drift trend estimator is obtained by performing first-order differentiation on the Doppler shift expression, is a predicted frequency shift at a next time.

[0014] As an implementation manner of the embodiment of the present application, the device further comprises: a signal parameter obtaining module, configured to obtain a signal parameter of a received signal; and the signal parameter at least includes a carrier-to-noise ratio, a phase change rate and a cross-correlation peak value; a comprehensive error factor calculation module, configured to calculate a comprehensive error factor of the received signal based on the signal parameters; A model fitting module is used to count the frequency shift values ​​of the most recent preset number of moments when the comprehensive error factor is greater than or equal to a preset threshold, calculate the frequency shift change value between every two adjacent moments based on each of the frequency shift values, and fit the frequency shift trend prediction model; The rescanning module is used to calculate the center value of the frequency scanning window according to the frequency shift change value and the frequency shift trend prediction model, and perform signal scanning on the target satellite again according to the center value of the frequency scanning window and the frequency scanning window.

[0015] As an implementation of an embodiment of the present application, the comprehensive error factor calculation module is specifically used to: Calculate the comprehensive error factor according to the following formula: : in, 、 、 All are pre-set weight coefficients; is the carrier-to-noise ratio, is the reference carrier-to-noise ratio, is the phase change rate, is the cross-correlation peak, is the ideal peak value.

[0016] As an implementation of an embodiment of the present application, the rescan module is specifically configured to: Calculate the frequency scan window center value according to the following formula: : in, is the frequency shift trend prediction model, is the average value of each of the frequency shift change values, is the preset feedback gain coefficient; in, 、 is the fitting coefficient, t is the time variable.

[0017] In a third aspect, an embodiment of the present application provides a computer device, comprising: a memory and a processor, wherein the memory and the processor are coupled; The memory is used to store one or more computer instructions; The processor is used to execute the one or more computer instructions to implement the satellite signal tracking method as described in the first aspect.

[0018] In a fourth aspect, an embodiment of the present application provides a computer readable storage medium, having stored thereon one or more computer instructions, which, when executed by a processor, implement the satellite signal tracking method according to the first aspect.

[0019] In a fifth aspect, the present application provides a computer program product, comprising a computer program, which, when executed by a processor, implements the satellite signal tracking method according to the first aspect.

[0020] In an embodiment of the present application, after the running linear velocity of the target satellite is acquired, the radial velocity of the target satellite relative to the ground terminal at the current time is calculated according to the running linear velocity and the angle of the target satellite relative to the ground terminal at the current time, then a Doppler shift expression is acquired, a drift trend estimator is established according to the Doppler shift expression, a frequency shift predictor is constructed according to the drift trend estimator, and finally the predicted frequency shift at the next time is calculated according to the radial velocity and the frequency shift predictor, and the target satellite is scanned according to the predicted frequency shift and the pre-set frequency scanning window. That is, in an embodiment of the present application, the predicted frequency shift of the target satellite at the next time can be calculated based on the constructed frequency shift predictor only after the radial velocity of the target satellite is calculated. The algorithm process is simple, time-consuming is short, and the satellite signal tracking lag is small, thereby the stability of satellite signal tracking can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, 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 only some embodiments of the present application. Those skilled in the art can obtain other drawings according to these drawings without any creative effort.

[0022] Figure 1 Fig. 1 shows a flow diagram of a satellite signal tracking method according to an embodiment of the present application; Figure 2 Fig. 2 shows a structural diagram of a satellite signal tracking device according to an embodiment of the present application; Figure 3 Fig. 3 shows a structural diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0023] The following will be combined with the accompanying drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0024] It should be noted that the terms "including" and "having" and any variations thereof in the embodiments and drawings of this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to the process, method, product, or device.

[0025] The embodiments of the present application disclose a satellite signal tracking method, apparatus, computer device, and storage medium, which can improve the stability of satellite signal tracking. The embodiments of the present application are described in detail below.

[0026] Low-orbit satellites, also known as LEO satellites, generally refer to artificial satellites with orbital altitudes between 200 and 2000 kilometers. They are primarily used for military target detection, making it easier to obtain high-resolution images of targets. They are also used for mobile communications, as their low orbital altitude reduces transmission latency and path loss.

[0027] In low-Earth orbit satellite communications, the high-speed movement of satellites causes the received signal's frequency to fluctuate significantly and rapidly, with Doppler shifts reaching up to hundreds of kHz. Therefore, accurately calculating and tracking satellite frequencies is a key challenge. Large frequency calculation errors can lead to unsuccessful tracking. For example, incorrect frequency scanning or a frequency scanning window that doesn't cover the actual signal frequency can result in missed detections or falsely misjudged signals.

[0028] Figure 1 The following is a flow chart of a satellite signal tracking method provided by an embodiment of the present application. The method can be applied to a ground terminal. The process may include the following steps: S110: Obtain the running linear velocity of the target satellite, and calculate the radial velocity of the target satellite relative to the ground terminal at the current moment based on the running linear velocity and the angle between the target satellite and the ground terminal at the current moment.

[0029] In an embodiment of the present application, a ground terminal can track signals from multiple low-orbit satellites, wherein the signal tracking method is the same for each low-orbit satellite. Therefore, the satellite signal tracking method of the embodiment of the present application can be described by taking the ground terminal tracking any low-orbit satellite, which can be referred to as the target satellite, as an example.

[0030] When a low-orbit satellite orbits the Earth in space, its speed, also known as its linear velocity, is not always toward the ground terminal. However, during signal tracking, only the radial component of the satellite relative to the ground terminal (LOS direction, Line of Sight) affects the frequency shift prediction.

[0031] Therefore, in the embodiment of the present application, after obtaining the linear velocity of the target satellite, the radial velocity of the target satellite relative to the ground terminal at the current moment can be calculated based on the linear velocity and the angle of the target satellite relative to the ground terminal at the current moment. The angle of the target satellite relative to the ground terminal can be measured in real time. When calculating the radial velocity, in one implementation, the radial velocity of the target satellite relative to the ground terminal at the current moment can be calculated according to the following formula: : = in, is the linear velocity of the satellite; It is the angle between the satellite and the ground terminal receiver, which changes over time in the field of view; when the satellite rises from the horizon, θ≈90 ∘ ,so ≈0; when the satellite passes overhead, θ≈0 ∘ ,but ≈ .

[0032] LEO satellites usually orbit at an altitude of 550 km, and their linear speed once around the Earth is approximately: in, is the gravitational constant; is the mass of the Earth; is the radius of the Earth (about 6371 km); is the satellite altitude (e.g. 550 km).

[0033] S120: Acquire a pre-built Doppler frequency shift expression, establish a drift trend estimator according to the Doppler frequency shift expression, and construct a frequency shift predictor according to the drift trend estimator.

[0034] In the process of tracking the target satellite signal, if the frequency shift of the target satellite can be accurately determined, the target satellite can be stably tracked. In the embodiment of the present application, the radial velocity of the LEO satellite relative to the ground terminal can be used. Based on this, the following Doppler shift expression is constructed to estimate the Doppler shift : in, is the radial velocity of the satellite relative to the ground terminal (unit: m / s); The speed of light (about 3×10 8 m / s); is the carrier frequency (e.g., approximately 14 GHz for Ku-band).

[0035] Furthermore, a drift trend estimator can be established based on the Doppler shift expression, and a frequency shift predictor can be constructed based on the drift trend estimator. In one implementation, the Doppler shift expression can be first-order differentiated to obtain the drift trend estimator, and then the frequency shift predictor can be constructed based on the Doppler shift expression and the drift trend estimator.

[0036] For example, you can Perform first-order difference to obtain the drift trend estimator : in, is the Doppler shift at the current moment, is the Doppler shift at the previous moment.

[0037] Further build the predictor: in, is the predicted frequency shift at the next moment.

[0038] That is to say, the frequency shift change value of the target satellite can be determined first, and then the sum of the frequency shift at the current moment and the frequency shift change value can be used as the predicted frequency shift at the next moment.

[0039] The Doppler shift at the current moment indicates the deviation of the current satellite signal frequency relative to the stationary state. is the frequency shift difference between the current moment and the previous moment, representing the trend of frequency shift change; is the predicted frequency shift at the next moment, that is, the predicted value used to guide frequency tracking.

[0040] S130: Calculate the predicted frequency shift at the next moment according to the radial velocity and the frequency shift predictor.

[0041] According to the above expression, after the radial velocity of the target satellite relative to the ground terminal at the current moment is calculated, it can be substituted into the Doppler frequency shift expression to obtain the Doppler frequency shift of the target satellite at the current moment. Furthermore, the frequency shift change value can be calculated based on the drift trend estimator, and finally, the predicted frequency shift at the next moment can be calculated based on the predictor.

[0042] S140: Scan the target satellite for signals according to the predicted frequency shift and the preset frequency scanning window.

[0043] After calculating the predicted frequency shift of the target satellite at the next moment, the target satellite signal can be scanned according to the predicted frequency shift and the pre-set frequency scanning window. Set the frequency search window (e.g. ±5 kHz) and scan quickly.

[0044] After scanning, the system can also detect the presence of a signal, using methods such as Fast Fourier Transform (FFT) and Maximum Likelihood Detection. If a match is successful, indicating the signal is present, the system enters lock mode; otherwise, a new search is triggered. In satellite signal reception and tracking, "lock mode" refers to the state in which the receiving terminal successfully captures and stably tracks the target signal.

[0045] In an embodiment of the present application, after obtaining the target satellite's operating linear velocity, the radial velocity of the target satellite relative to the ground terminal at the current moment can be calculated based on the operating linear velocity and the angle of the target satellite relative to the ground terminal at the current moment. Then, a pre-constructed Doppler frequency shift expression is obtained, a drift trend estimator is established based on the Doppler frequency shift expression, and a frequency shift predictor is constructed based on the drift trend estimator. Finally, the predicted frequency shift at the next moment is calculated based on the radial velocity and the frequency shift predictor, and the target satellite is scanned for signals based on the predicted frequency shift and a pre-set frequency scanning window. That is to say, in an embodiment of the present application, only after calculating the radial velocity of the target satellite, the predicted frequency shift of the target satellite at the next moment can be calculated based on the constructed frequency shift predictor. The algorithm process is simple, time-saving, and the satellite signal tracking lag is small, thereby improving the stability of satellite signal tracking.

[0046] It is understandable that since the frequency of low-orbit satellites may mutate, the signal tracking effect may be good or poor during the satellite signal tracking process.

[0047] In one implementation of an embodiment of the present application, in order to further improve the stability of satellite signal tracking, after performing signal scanning on the target satellite, the received signal can also be detected. When the received signal is poor, the center value of the frequency scanning window can be adjusted and the drift trend prediction model can be refitted.

[0048] In one implementation, the ground terminal can first obtain signal parameters of the received signal, which include at least the carrier-to-noise ratio, phase change rate, and cross-correlation peak. Based on the signal parameters, the ground terminal calculates a comprehensive error factor of the received signal. When the comprehensive error factor is greater than or equal to a preset threshold, the ground terminal calculates the frequency shift values ​​for the most recent preset number of moments, calculates the frequency shift change between two adjacent moments based on each frequency shift value, and obtains a frequency shift trend prediction model by fitting. Finally, based on the frequency shift change value and the frequency shift trend prediction model, the ground terminal calculates the center value of the frequency scanning window, and based on the center value of the frequency scanning window and the frequency scanning window, the ground terminal performs a signal scan on the target satellite again. The above signal parameters can be extracted in real time by the ground terminal from the actual received satellite signal.

[0049] The integrated error factor reflects the error between the actual received signal and the ideal signal. A larger integrated error factor indicates a greater error between the actual received signal and the ideal signal, resulting in poor signal tracking. A smaller integrated error factor indicates a smaller error between the actual received signal and the ideal signal, resulting in better signal tracking.

[0050] For example, the comprehensive error factor can be calculated according to the following formula: : in, 、 、 These are all pre-set weight coefficients that can be dynamically adjusted according to the application scenario; is the carrier-to-noise ratio, is the reference carrier-to-noise ratio, is the phase change rate, is the cross-correlation peak, is the ideal peak value to be set.

[0051] I understand. 、 、 Three weight coefficients are used to adjust the error factor The importance of each indicator in the ,can usually be set dynamically according to the specific application scenario.,Specifically, It is used to measure the deviation of the carrier-to-noise ratio C / N0. If the channel quality (such as multipath interference) changes drastically, this item can be appropriately increased. Reflecting the influence of phase continuity, suitable for coherent carrier tracking scenarios; Indicates the correlation peak, which is an important basis for signal existence judgment, especially suitable for initial acquisition or when there is a risk of frequency hopping.

[0052] In an implementation manner, the values of the weight coefficients can be set through experimental simulation or online training, such as determining a set of reasonable initial values through a least mean square error criterion. For example, the values can be set as follows: = 0.4, = 0.3, = 0.3.

[0053] is a reference carrier-to-noise ratio. This value is a reference under an empirically “good signal” condition. When setting, the following methods are usually referred to: obtained from historical measurement statistics, for example, the average C / N0 of the ground terminal tracking the signal in this frequency band is 38 dB-Hz, and can be set as 38 dB-Hz.

[0054] is a set ideal peak value. This is usually the maximum value that the cross-correlation function should reach in the ideal matching case, reflecting the signal locking state. Specifically, it can be set according to the maximum correlation peak in the simulation without frequency offset / phase error; or it can be estimated according to the average peak value in multiple acquisition success samples. For example, the average of multiple correlation peak values in steady-state tracking can be taken, such as if the measured correlation peak value is stable near 1.0, then = 0.95.

[0055] When E(t) > ϵ, it indicates that the signal tracking effect is poor. In this case, feedback correction can be triggered to update the correction term, adjust the frequency scanning window center value, and re-fit the drift trend prediction model.

[0056] Specifically, the frequency shift data points at the last N time points can be collected as a time series of frequency change rates; a linear model is fitted by applying a weighted least squares (WLS) method: wherein, , is a fitting coefficient, is a time variable. This is a trend prediction, that is, the future frequency center position is predicted through the historical frequency data change trend. Moreover, the weight of each sample point can be set as 1 / E(t), that is, the better the signal quality (the smaller the comprehensive error factor), the greater the influence of the point on fitting, thereby improving the robustness of the prediction model.

[0057] In one implementation, the frequency scan window center value can be adjusted to : in, is the frequency shift trend prediction model, is the average value of each of the frequency shift change values, It is a preset feedback gain coefficient, which can be adaptively adjusted according to the historical tracking offset.

[0058] In an embodiment of the present application, after performing signal scanning on the target satellite, the received signal can also be detected. When the received signal is poor, the center value of the frequency scanning window can be adjusted and the drift trend prediction model can be refitted, thereby further improving the stability of satellite signal tracking.

[0059] In a specific embodiment, during a ground station test, the target is a LEO satellite at an orbital altitude of approximately 550 km, with a carrier frequency of 14.25 GHz and a minimum elevation angle of 30°. Orbital mechanics indicates that the maximum radial velocity of the satellite relative to the ground is approximately 7.5 km / s, and the maximum Doppler shift is: Using the method provided in the embodiments of the present application for simulation, the average error of the prediction model is less than ±500 Hz, the tracking retention rate is above 90%, and the first capture time is less than 1 second, which is far superior to the performance of traditional prediction methods (the retention rate is only about 72%, and the first capture time is about 2.3 seconds).

[0060] Furthermore, the method provided by the embodiments of this application was embedded in an FPGA+DSP hardware platform for verification. Using a 256-point FFT module with a 10 ms update period, the signal feature feedback processing module occupied approximately 5% of the logic resources. In real-world conditions, the method was able to stably track over 20 low-orbit satellites, maintaining an average C / N0 ratio above 38 dB-Hz.

[0061] In addition, the method provided in the embodiment of the present application is also applicable to different orbital inclinations (0°–98°) and different communication frequency bands (such as Ku, Ka, etc.), by adjusting Δt, window width, feedback coefficient α i Parameters such as GNSS and GNSS can be quickly adapted to different constellation systems.

[0062] Figure 2 A schematic structural diagram of a satellite signal tracking device provided in an embodiment of the present application is shown. The device is applied to a ground terminal and includes: The velocity acquisition module 210 is configured to acquire the linear velocity of the target satellite and calculate the radial velocity of the target satellite relative to the ground terminal at the current moment based on the linear velocity and the angle between the target satellite and the ground terminal at the current moment. A predictor building module 220 is configured to obtain a pre-built Doppler frequency shift expression, establish a drift trend estimator based on the Doppler frequency shift expression, and build a frequency shift predictor based on the drift trend estimator; a frequency shift prediction module 230, configured to calculate a predicted frequency shift at a next moment based on the radial velocity and the frequency shift predictor; The signal tracking module 240 is configured to perform signal scanning on the target satellite according to the predicted frequency shift and a preset frequency scanning window.

[0063] As an implementation of the embodiment of the present application, the predictor construction module 220 is specifically configured to: Performing a first-order difference on the Doppler frequency shift expression to obtain a drift trend estimator; A frequency shift predictor is constructed based on the Doppler frequency shift expression and the drift trend estimator.

[0064] As an implementation of an embodiment of the present application, the predictor construction module 220 is specifically configured to construct the following frequency shift predictor: in, is the Doppler shift at the current moment, is the drift trend estimator, the is the predicted frequency shift at the next moment.

[0065] As an implementation of the embodiment of the present application, the device further includes: A signal parameter acquisition module is used to acquire signal parameters of the received signal; the signal parameters include at least carrier-to-noise ratio, phase change rate and cross-correlation peak; a comprehensive error factor calculation module, configured to calculate a comprehensive error factor of the received signal based on the signal parameters; A model fitting module is used to count the frequency shift values ​​of the most recent preset number of moments when the comprehensive error factor is greater than or equal to a preset threshold, calculate the frequency shift change value between every two adjacent moments based on each of the frequency shift values, and fit the frequency shift trend prediction model; The rescanning module is used to calculate the center value of the frequency scanning window according to the frequency shift change value and the frequency shift trend prediction model, and perform signal scanning on the target satellite again according to the center value of the frequency scanning window and the frequency scanning window.

[0066] As an implementation of an embodiment of the present application, the comprehensive error factor calculation module is specifically used to: Calculate the comprehensive error factor according to the following formula: : in, 、 、 All are pre-set weight coefficients; is the carrier-to-noise ratio, is the reference carrier-to-noise ratio, is the phase change rate, is the cross-correlation peak, is the ideal peak value.

[0067] As an implementation of an embodiment of the present application, the rescan module is specifically configured to: Calculate the frequency scan window center value according to the following formula: : in, is the frequency shift trend prediction model, is the average value of each of the frequency shift change values, is the preset feedback gain coefficient; in, 、 is the fitting coefficient, t is the time variable.

[0068] In an embodiment of the present application, after obtaining the target satellite's operating linear velocity, the radial velocity of the target satellite relative to the ground terminal at the current moment can be calculated based on the operating linear velocity and the angle of the target satellite relative to the ground terminal at the current moment. Then, a pre-constructed Doppler frequency shift expression is obtained, a drift trend estimator is established based on the Doppler frequency shift expression, and a frequency shift predictor is constructed based on the drift trend estimator. Finally, the predicted frequency shift at the next moment is calculated based on the radial velocity and the frequency shift predictor, and the target satellite is scanned for signals based on the predicted frequency shift and a pre-set frequency scanning window. That is to say, in an embodiment of the present application, only after calculating the radial velocity of the target satellite, the predicted frequency shift of the target satellite at the next moment can be calculated based on the constructed frequency shift predictor. The algorithm process is simple, time-saving, and the satellite signal tracking lag is small, thereby improving the stability of satellite signal tracking.

[0069] Next, we will introduce a computer device provided by an embodiment of the present application. Figure 3 , Figure 3A schematic diagram of the structure of a computer device provided in an embodiment of the present application, the computer device comprising: one or more processors 40; The processor 40 is coupled to a storage device 41, and the storage device 41 is used to store one or more programs. When the one or more programs are executed by the one or more processors 40, the electronic device can realize the following Figure 1 A technical solution of the satellite signal tracking method.

[0070] The embodiment of the present application also provides a computer-readable storage medium on which a computer program is stored, and when the program is executed by a processor, the following is achieved: Figure 1 A technical solution of the satellite signal tracking method.

[0071] The present application provides a computer program product, which includes a computer program. When the computer program is executed by a processor, Figure 1 A technical solution of the satellite signal tracking method.

[0072] Those skilled in the art will understand that the accompanying drawings are merely schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present application.

[0073] Those skilled in the art will appreciate that the modules in the devices of the embodiments may be distributed in the devices of the embodiments as described in the embodiments, or may be located in one or more devices different from the embodiments with corresponding changes. The modules of the above embodiments may be combined into one module or further divided into multiple submodules.

[0074] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application 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 embodiments of the present application.

Claims

1. A satellite signal tracking method, characterized in that: The method is applied to a ground terminal and includes: Obtaining the linear velocity of the target satellite, and calculating the radial velocity of the target satellite relative to the ground terminal at the current moment based on the linear velocity and the angle between the target satellite and the ground terminal at the current moment; Obtaining a pre-constructed Doppler frequency shift expression, establishing a drift trend estimator based on the Doppler frequency shift expression, and constructing a frequency shift predictor based on the drift trend estimator; Calculating a predicted frequency shift at a next moment according to the radial velocity and the frequency shift predictor; According to the predicted frequency shift and a preset frequency scanning window, a signal scan is performed on the target satellite.

2. The method according to claim 1, characterized in that The steps of establishing a drift trend estimator according to the Doppler frequency shift expression and constructing a frequency shift predictor according to the drift trend estimator include: Performing a first-order difference on the Doppler frequency shift expression to obtain a drift trend estimator; A frequency shift predictor is constructed based on the Doppler frequency shift expression and the drift trend estimator.

3. The method according to claim 2, characterized in that The step of constructing a frequency shift predictor according to the Doppler frequency shift expression and the drift trend estimator comprises: Construct the following frequency shift predictor: in, is the Doppler shift at the current moment, is the drift trend estimator, the is the predicted frequency shift at the next moment.

4. The method according to any one of claims 1 to 3, characterized in that The method further comprises: Acquiring signal parameters of the received signal; the signal parameters include at least carrier-to-noise ratio, phase change rate, and cross-correlation peak; Calculating a comprehensive error factor of the received signal based on the signal parameters; When the comprehensive error factor is greater than or equal to a preset threshold, the frequency shift values ​​of the most recent preset number of moments are counted, the frequency shift change value between every two adjacent moments is calculated based on each of the frequency shift values, and a frequency shift trend prediction model is obtained by fitting; A frequency scanning window center value is calculated according to the frequency shift change value and the frequency shift trend prediction model, and a signal scan is performed on the target satellite again according to the frequency scanning window center value and the frequency scanning window.

5. The method according to claim 4, characterized in that The step of calculating the comprehensive error factor of the received signal according to the signal parameters includes: Calculate the comprehensive error factor according to the following formula: : in, 、 、 All are pre-set weight coefficients; is the carrier-to-noise ratio, is the reference carrier-to-noise ratio, is the phase change rate, is the cross-correlation peak, is the ideal peak value.

6. The method according to claim 4, characterized in that The step of calculating the center value of the frequency scanning window according to the frequency shift change value and the frequency shift trend prediction model includes: Calculate the frequency scan window center value according to the following formula: : in, is the frequency shift trend prediction model, is the average value of each of the frequency shift change values, is the preset feedback gain coefficient; in, 、 is the fitting coefficient, t is the time variable.

7. A satellite signal tracking device, characterized in that: The device is applied to a ground terminal and includes: a velocity acquisition module, configured to acquire the linear velocity of the target satellite and calculate the radial velocity of the target satellite relative to the ground terminal at the current moment based on the linear velocity and the angle between the target satellite and the ground terminal at the current moment; a predictor construction module, configured to obtain a pre-constructed Doppler frequency shift expression, establish a drift trend estimator based on the Doppler frequency shift expression, and construct a frequency shift predictor based on the drift trend estimator; a frequency shift prediction module, configured to calculate a predicted frequency shift at a next moment based on the radial velocity and the frequency shift predictor; The signal tracking module is used to perform signal scanning on the target satellite according to the predicted frequency shift and a preset frequency scanning window.

8. The device according to claim 7, characterized in that The predictor building module is specifically used to: Performing a first-order difference on the Doppler frequency shift expression to obtain a drift trend estimator; A frequency shift predictor is constructed based on the Doppler frequency shift expression and the drift trend estimator.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are coupled; The memory is used to store one or more computer instructions; The processor is configured to execute the one or more computer instructions to implement the satellite signal tracking method according to any one of claims 1 to 6.

10. A readable storage medium having one or more computer instructions stored thereon, characterized in that: The instruction is executed by a processor to implement the satellite signal tracking method according to any one of claims 1 to 6.

Images