Star chain satellite capturing and tracking method and device based on carrier-to-noise ratio

Abstract

The invention provides a star chain satellite capturing and tracking method and device based on a carrier-to-noise ratio, and belongs to the technical field of satellite finding. The method comprises the following steps: sampling satellite signals through a portable frequency spectrograph according to pre-configured frequency spectrograph parameters to obtain frequency spectrum data, and extracting I / Q data from the frequency spectrum data; carrying out direct drift removal and windowing processing on the I / Q data to obtain a preprocessed satellite signal, then carrying out FFT (Fast Fourier Transform), determining a frequency component of the satellite signal, and calculating a ground noise value of the satellite signal; then, moving a negative frequency component in the frequency spectrum data to a positive frequency component, and calculating a power level average value of nine strongest spectral lines in a satellite chain downlink signal; and finally, according to the bottom noise value and the average value of the power levels of the nine strongest spectral lines, calculating the carrier-to-noise ratio CNR of the beacon signal, and transmitting the carrier-to-noise ratio CNR to an antenna controller. According to the method, the carrier-to-noise ratio is solved by means of accumulating and averaging the beacon signals, and the star chain satellites can be captured and stably tracked.

Description

Technical Field

[0001] The present invention relates to the field of satellite search technology, and in particular to a method and device for capturing and tracking Starlink satellites based on carrier-to-noise ratio. Background Art

[0002] Starlink satellites can monitor land targets around the clock and in all weather conditions, and can provide accurate location and navigation for military equipment. In addition to multiple functions such as communication, reconnaissance, and navigation, Starlink satellites also have certain application prospects. In terms of communication, Starlink can be used in low-Earth orbit to achieve worldwide goals.

[0003] At present, there is no Starlink service signal in China. We mainly rely on beacon signals to track Starlink satellites. However, these signals are fluctuating and unstable, making it easy to lose signal contact using traditional tracking methods. In order to solve this problem, it is necessary to develop a new satellite capture and tracking method to achieve the capture and stable tracking of Starlink satellites, so as to monitor their activity trajectories and control their movements in real time. Summary of the invention

[0004] In view of this, an embodiment of the present invention provides a Starlink satellite capture and tracking method and device based on carrier-to-noise ratio, so as to solve the problem that traditional satellite tracking methods are difficult to stably track Starlink satellites.

[0005] The technical solution adopted by the present invention is: In a first aspect, the present invention provides a Starlink satellite capture and tracking method based on carrier-to-noise ratio, comprising: According to the pre-configured spectrum analyzer parameters, the satellite signal is sampled by the portable spectrum analyzer to obtain the spectrum data corresponding to the satellite signal, and I / Q data is extracted from the spectrum data; Perform direct drift removal and windowing processing on the I / Q data to obtain the preprocessed satellite signal; Perform FFT transformation on the pre-processed satellite signal to determine the frequency components of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency components; Move the negative frequency components in the spectrum data to the positive frequency components, and calculate the average power level of the 9 strongest spectral lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal; Based on the background noise value and the average power level of the nine strongest spectral lines, the carrier-to-noise ratio CNR of the Starlink satellite beacon signal is calculated, and the carrier-to-noise ratio CNR is transmitted to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

[0006] Further, the I / Q data is subjected to direct drift removal and windowing processing to obtain a preprocessed satellite signal, including: Calculate the average value of I / Q data: , in, represents the Q value of index i, is the average value of Q data, The number of points set for FFT transformation; is the value of I with index i, is the average value of I data; Subtract the average value of the I / Q data from each data point of the I / Q data to remove the DC offset in the satellite signal; Based on the I / Q data after removing the DC offset, the windowing function is called to generate the FlatTop window coefficient, and each data point of the I / Q data is multiplied by the FlatTop window coefficient to obtain the preprocessed satellite signal.

[0007] Further, performing FFT transformation on the preprocessed satellite signal to determine the frequency component of the satellite signal, and calculating the noise floor value of the satellite signal based on the frequency component includes: Copy the I / Q data from the pre-processed satellite signal to the FFTW library and input it into an array; Perform FFT transformation on the array to transform the preprocessed satellite signal from the time domain to the frequency domain and determine the frequency components of the satellite signal; According to the frequency components of the satellite signal, the power spectrum density of each frequency point is calculated. P [ k ], and according to the power spectral density P [ k ] Calculate the dBm value and frequency value of each frequency point; The average power level of the background noise is calculated through 8192 sampling points of the satellite signal to obtain the background noise value of the satellite signal. P n .

[0008] Further, the calculating the average power level of the nine strongest spectral lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal includes: Analyze the time-frequency domain frame structure of the Starlink downlink signal to determine the operating frequency band of the Starlink downlink signal; Arrange the 8192 sampling points of the current satellite signal in descending order according to the power level value, take the first 9 points as the 9 strongest spectral lines, and perform power level accumulation and average on the 9 strongest spectral lines to obtain the power level average value. : in, It represents the average value of the power level of the 9 strongest spectral lines; Indicates the power level of the spectral line with index i.

[0009] Furthermore, the pre-configured spectrum analyzer parameters include: setting the sampling rate to 1 MHz, the center frequency to the corresponding intermediate frequency beacon frequency, the number of FFT transformation points to 8192; the intermediate frequency beacon frequency includes 1575 MHz, 1825 MHz, 1350 MHz and 1850 MHz.

[0010] In a second aspect, the present invention provides a Starlink satellite capture and tracking device based on carrier-to-noise ratio, comprising: A data sampling module is used to sample satellite signals through a portable spectrum analyzer according to pre-configured spectrum analyzer parameters, obtain spectrum data corresponding to the satellite signals, and extract I / Q data from the spectrum data; A data preprocessing module is used to perform direct drift removal and windowing processing on the I / Q data to obtain a preprocessed satellite signal; A noise floor calculation module is used to perform FFT transformation on the pre-processed satellite signal, determine the frequency component of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency component; The spectrum shifting module is used to shift the negative frequency components in the spectrum data to the positive frequency components, and calculate the average power level of the nine strongest spectrum lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal; The carrier-to-noise ratio calculation module is used to calculate the carrier-to-noise ratio CNR of the Starlink satellite beacon signal based on the background noise value and the average power level of the 9 strongest spectral lines, and transmit the carrier-to-noise ratio CNR to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

[0011] In summary, the beneficial effects of the present invention are as follows: The present invention provides a Starlink satellite capture and tracking method based on carrier-to-noise ratio. The method first obtains I / Q data from the spectrometer according to pre-configured spectrometer parameters, and then performs direct drift removal and windowing processing on the I / Q data to make the spectrum clearer, reduce aliasing, and ensure the accuracy of signal processing. Then, perform FFT transformation, calculate the power spectrum density and convert it into dBm units, move the spectrum data, calculate the average power level of the Starlink downlink signal, calculate the carrier-to-noise ratio SNR based on the power spectrum density and the average power level, and send it to the antenna controller to achieve capture and stable tracking of the Starlink satellite. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the technical solution of the embodiment of the present invention, the following is a brief introduction to the drawings required for use in the embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work, and these are all within the protection scope of the present invention.

[0013] Figure 1 The present invention is a flow chart of a Starlink satellite capture and tracking method based on carrier-to-noise ratio; Figure 2 This is a schematic diagram of the time-frequency domain frame structure of the Starlink downlink signal; Figure 3 This is a functional module diagram of a Starlink satellite capture and tracking device based on carrier-to-noise ratio according to an embodiment of the present invention; Figure 4 It is an execution flow chart of the Starlink satellite capture and tracking device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiment of the present invention. It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. If there is no conflict, the various features of the present invention and the embodiments can be combined with each other, all within the scope of protection of the present invention.

[0015] The monitoring of Starlink satellites is critical to national security because they can enhance military reconnaissance and communication capabilities, threaten national defense security, change the way of warfare, challenge information sovereignty and supervision, threaten the security of space assets, and bring new challenges to space security. These satellites may intensify the arms race in outer space and have a profound impact on the global strategic balance.

[0016] In China, since Starlink service signal coverage has not yet been implemented, we currently rely mainly on beacon signals to track Starlink satellites. However, the fluctuation and instability of these beacon signals cause traditional tracking technology to be easily interrupted. The method of the present invention has been continuously tested and improved to perfectly solve this problem and achieve stable and continuous tracking of Starlink satellite signals. The detailed implementation process of the present invention is shown in the following embodiments.

[0017] Example 1: Reference Figure 1 As shown, Figure 1 This is a flow chart of a Starlink satellite capture and tracking method based on carrier-to-noise ratio of the present invention. Figure 1As shown, a Starlink satellite capture and tracking method based on carrier-to-noise ratio of the present invention is applied to tracking and monitoring of Starlink satellites, and the method includes: According to the pre-configured spectrum analyzer parameters, the satellite signal is sampled by the portable spectrum analyzer to obtain the spectrum data corresponding to the satellite signal, and I / Q data is extracted from the spectrum data; Perform direct drift removal and windowing processing on the I / Q data to obtain the preprocessed satellite signal; Perform FFT transformation on the pre-processed satellite signal to determine the frequency components of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency components; Move the negative frequency components in the spectrum data to the positive frequency components, and calculate the average power level of the 9 strongest spectral lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal; Based on the background noise value and the average power level of the nine strongest spectral lines, the carrier-to-noise ratio CNR of the Starlink satellite beacon signal is calculated, and the carrier-to-noise ratio CNR is transmitted to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

[0018] Specifically, the embodiment of the present invention first obtains I data and Q data from the spectrum analyzer, then performs de-drift processing on the I data and Q data, uses the Flat Top function to perform windowing processing, and performs FFT transformation, then calculates the power spectral density and converts it into dBm units, calculates the carrier-to-noise ratio SNR and sends it to the antenna controller.

[0019] Among them, I / Q data specifically includes I data and Q data. I / Q = in-phase / quadrature, which refers to the in-phase / quadrature data of the RF signal. The I / Q value refers to two complex components, namely the quadrature amplitude component In-phase (I) and Quadrature (Q). I / Q values ​​are widely used in wireless communication systems, especially in the field of digital signal processing. In a digital signal receiver, the received radio wave signal is converted into I / Q values ​​after frequency conversion, and then digital signal processing is performed on it. I / Q values ​​are also used to determine the phase and amplitude of the signal, so they are also widely used in radio communication and radar systems.

[0020] Further, in the embodiment of the present invention, the pre-configured spectrum analyzer parameters include: setting the sampling rate to 1 MHz, the center frequency to the corresponding intermediate frequency beacon frequency, and the number of FFT transformation points to 8192. Among them, the intermediate frequency beacon frequency includes 1575 MHz, 1825 MHz, 1350 MHz and 1850 MHz.

[0021] Further, in the embodiment of the present invention, the I / Q data is subjected to direct drift removal and windowing processing to obtain a preprocessed satellite signal, which specifically includes the following processes: The purpose of removing direct drift is to improve the accuracy and reliability of the signal, avoid distortion in spectrum analysis, improve the dynamic range and performance of the system, and ensure that weak signals are not overwhelmed by drift, thereby improving the effect of signal processing. The process of removing direct drift is as follows: Calculate the average value of I / Q data: , in, represents the Q value of index i, is the average value of Q data, The number of points set for FFT transformation; is the value of I with index i, is the average value of I data.

[0022] The average value of the I / Q data is subtracted from each data point of the I / Q data to remove the DC offset in the satellite signal.

[0023] Windowing is mainly to reduce spectrum leakage caused by signal truncation, reduce discontinuity at the edge of the signal, reduce edge effects, improve spectrum resolution, make the spectrum clearer, reduce aliasing, and ensure the accuracy of signal processing. The windowing process of the embodiment of the present invention is as follows: Based on the I / Q data after removing the DC offset, the windowing function is called to generate the FlatTop window coefficient, and each data point of the I / Q data is multiplied by the FlatTop window coefficient to obtain the preprocessed satellite signal.

[0024] Among them, for a given window length n and window index i, the window coefficient w(i) of the flat top window (FlatTop) can be calculated by the following formula: The coefficient a 0 , a 1 , a 2 , a 3 , a 4 The values ​​are: a 0 =0.21557895; a 1 =0.41663158; a 2 =0.277263158; a3 =0.083578947; a 4 =0.006947368; Finally, the window coefficient is applied to the Q data and I data, and each data point is multiplied by the window coefficient w(i) to obtain the preprocessed satellite signal.

[0025] Furthermore, in an embodiment of the present invention, an FFT transform is performed on the preprocessed satellite signal to determine the frequency component of the satellite signal, and a noise floor value of the satellite signal is calculated based on the frequency component. The process specifically includes: Convert the signal from the time domain to the frequency domain to analyze the frequency components of the signal. Specifically, copy the I / Q data from the preprocessed satellite signal to the FFTW library and input it into the array.

[0026] Perform FFT transformation on the array to transform the preprocessed satellite signal from the time domain to the frequency domain and determine the frequency components of the satellite signal.

[0027] For a sequence x[n] of length N, its discrete Fourier transform (DFT) is defined as: in: X [ k ] is the sequence x [ n ]’s kth DFT coefficient; x [ n ] is the input array; k is the frequency index, ranging from 0 to N -1; j is an imaginary unit, satisfying j²=-1. Discrete Fourier Transform (DFT) is a discrete form of Fourier Transform in both time domain and frequency domain, which transforms the sampling of time domain signal into sampling in discrete time Fourier Transform (DTFT) frequency domain. Discrete Fourier Transform is the spectrum of sequence x(n) sampled at N points on [0,2π] at equal intervals, that is, the discretization of the sequence spectrum.

[0028] Among them, the present invention uses fast Fourier transform (FFT) to transform the data, so the present invention uses FFTW library to transform the data. FFTW is a high-performance fast Fourier transform (FFT) library written in C language, which supports various types of data transformations, including complex, real, symmetric and multidimensional transformations. The library can efficiently process data sets of any size.

[0029] According to the frequency components of the satellite signal, the power spectrum density of each frequency point is calculated. P [ k ], and according to the power spectral densityP [ k ]Calculate the dBm value and frequency value of each frequency point.

[0030] Specifically, when calculating the power spectral density (PSD) at each frequency point, the square of the DFT modulus is divided by the length N of the signal and the sampling period , and the power spectral density is obtained P [ k ]: Then calculate the dBm value and frequency value of each frequency point. dBm represents the unit of absolute power value, which is used to describe the strength and power level of the signal.

[0031] Finally, the average power level of the background noise is calculated through the 8192 sampling points of the spectrum analyzer to obtain the background noise value of the satellite signal. P n : .

[0032] Since there are many sampling points, even if the power levels of some spectral lines are high, after calculating the average value of all points, the background noise will be closer to the average value, so we believe that P n It is the noise floor value.

[0033] Specifically, in the embodiment of the present invention, the spectrum data is moved so that the negative frequency part is moved to the positive frequency part, which makes the spectrum data more intuitive and easy to process, and simplifies the subsequent spectrum analysis and visualization work. For example, assuming that the sampling point is 8, the initial value of the dBm array is [a, b, c, d, e, f, g, h], where a, b, c, d are the positive frequency parts, and e, f, g, h are the negative frequency parts. After the spectrum is moved, it becomes [e, f, g, h, a, b, c, d].

[0034] Further, in an embodiment of the present invention, the power level average of the nine strongest spectral lines in the Starlink downlink signal is calculated based on the time-frequency domain frame structure of the Starlink downlink signal. The process specifically includes: Analyze the time-frequency domain frame structure of the Starlink downlink signal to determine the operating frequency band of the Starlink downlink signal.

[0035] Among them, the time-frequency domain frame structure of the Starlink downlink signal refers to Figure 2 As shown in the figure f represents frequency, t represents period, PSS represents primary synchronization signal, OFDM represents OFDM symbol, T fRepresents the frame period. Analysis of the time-frequency domain frame structure of the Starlink downlink signal shows that the downlink signal operates in the Ku band of 10.7~12.7GHz, with a total of 8 channels with a bandwidth of 250MHz, each of which consists of a 240MHz signal effective bandwidth and a 10MHz guard interval. The narrowband part consists of 9 single-tone signals, and the frequency interval between adjacent signals is equal, about 44kHz. The signal is located at the center frequency, just in the frequency band gap of the broadband signal. The main function of the single-tone signal is to serve as a beacon signal to characterize the existence of the satellite and provide a basis for the ground receiving terminal to search and track the satellite. The 9 single-tone signals of Starlink are concentrated in the 1MHz bandwidth of the center frequency. The ground terminal can detect whether there is a Starlink downlink signal using a smaller capture bandwidth. If there is a Starlink downlink signal, it must be among the 9 strongest spectral lines. Therefore, we can take out the power levels of the 9 strongest spectral lines and accumulate and average them, and then estimate the carrier-to-noise ratio to determine whether there is a Starlink signal at present.

[0036] Arrange the 8192 sampling points of the current satellite signal in descending order according to the power level value, take the first 9 points as the 9 strongest spectral lines, and perform power level accumulation and average on the 9 strongest spectral lines to obtain the power level average value. : in, It represents the average value of the power level of the 9 strongest spectral lines; Indicates the power level of the spectral line with index i.

[0037] Specifically, after calculating the noise floor value and the average power level of the nine strongest spectral lines, the embodiment of the present invention can calculate the carrier-to-noise ratio (CNR) and send it to the antenna controller. The process specifically includes: (1) According to the formula CNR = 10log ( P s / P n ), and calculate the carrier-to-noise ratio of the beacon signal. Tests have shown that when there is a Starlink satellite beacon signal, the calculated carrier-to-noise ratio is around 20dB.

[0038] (2) The carrier-to-noise ratio (CNR) is transmitted to the antenna controller through the serial port. The antenna controller controls the direction of the beam to achieve dynamic tracking of the antenna.

[0039] The antenna controller determines whether the current satellite signal is captured successfully based on the CNR value. If captured successfully, it continues tracking, otherwise it continues scanning.

[0040] At present, there is no effective method in China that can achieve continuous and stable tracking of Starlink satellites. Due to the fluctuations and instability of beacon signals, traditional methods are prone to losing signal contact. In order to solve this problem, the embodiment of the present invention has developed a method for capturing and tracking Starlink satellites using carrier-to-noise ratio information. This method uses the beacon signal cumulative average method to calculate the carrier-to-noise ratio, which can achieve the capture and stable tracking of Starlink satellites. After testing and verification, it was found that the effective elevation angle range of traditional electronic phased array antennas is limited to plus or minus 60 degrees when tracking Starlink satellite beacon signals. By adopting this method and using a variable inclination continuous section segment array (VICTS) antenna, the tracking range can be effectively expanded to an elevation angle of 15 to 90 degrees. Therefore, this new method combined with the use of VICTS antennas can significantly improve the tracking stability of Starlink satellite signals and reduce the risk of loss of connection.

[0041] Example 2: Reference Figure 3 As shown, the embodiment of the present invention further provides a Starlink satellite capture and tracking device based on carrier-to-noise ratio on the basis of embodiment 1, and the device includes: A data sampling module is used to sample satellite signals through a portable spectrum analyzer according to pre-configured spectrum analyzer parameters, obtain spectrum data corresponding to the satellite signals, and extract I / Q data from the spectrum data; A data preprocessing module is used to perform direct drift removal and windowing processing on the I / Q data to obtain a preprocessed satellite signal; A noise floor calculation module is used to perform FFT transformation on the pre-processed satellite signal, determine the frequency component of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency component; The spectrum shifting module is used to shift the negative frequency components in the spectrum data to the positive frequency components, and calculate the average power level of the nine strongest spectrum lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal; The carrier-to-noise ratio calculation module is used to calculate the carrier-to-noise ratio CNR of the Starlink satellite beacon signal based on the background noise value and the average power level of the 9 strongest spectral lines, and transmit the carrier-to-noise ratio CNR to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

[0042] Specifically, refer to Figure 4 The device execution process shown in the figure, after the Starlink satellite capture and tracking device of the embodiment of the present invention configures the spectrum analyzer parameters, it calculates the carrier-to-noise ratio CNR through dual threads. One thread is used to obtain I / Q data from the spectrum analyzer API interface in real time, and the other thread uses a for loop to pull the I / Q data, perform direct drift removal and windowing processing, calculate the carrier-to-noise ratio CNR and send it to the antenna controller.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A Starlink satellite capture and tracking method based on carrier-to-noise ratio, characterized in that: include: According to the pre-configured spectrum analyzer parameters, the satellite signal is sampled by the portable spectrum analyzer to obtain the spectrum data corresponding to the satellite signal, and I / Q data is extracted from the spectrum data; Perform direct drift removal and windowing processing on the I / Q data to obtain the preprocessed satellite signal; Perform FFT transformation on the pre-processed satellite signal to determine the frequency components of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency components; Move the negative frequency components in the spectrum data to the positive frequency components, and calculate the average power level of the 9 strongest spectral lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal; Based on the background noise value and the average power level of the nine strongest spectral lines, the carrier-to-noise ratio CNR of the Starlink satellite beacon signal is calculated, and the carrier-to-noise ratio CNR is transmitted to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

2. The Starlink satellite capture and tracking method based on carrier-to-noise ratio according to claim 1, characterized in that: The I / Q data is subjected to direct drift removal and windowing processing to obtain a preprocessed satellite signal, including: Calculate the average value of I / Q data: ， in, represents the Q value of index i, is the average value of Q data, The number of points set for FFT transformation; is the value of I with index i, is the average value of I data; Subtract the average value of the I / Q data from each data point of the I / Q data to remove the DC offset in the satellite signal; Based on the I / Q data after removing the DC offset, the windowing function is called to generate the FlatTop window coefficient, and each data point of the I / Q data is multiplied by the FlatTop window coefficient to obtain the preprocessed satellite signal.

3. The Starlink satellite capture and tracking method based on carrier-to-noise ratio according to claim 1, characterized in that: The performing FFT transformation on the pre-processed satellite signal to determine the frequency component of the satellite signal, and calculating the background noise value of the satellite signal based on the frequency component, includes: Copy the I / Q data from the pre-processed satellite signal to the FFTW library and input it into an array; Perform FFT transformation on the array to transform the preprocessed satellite signal from the time domain to the frequency domain and determine the frequency components of the satellite signal; According to the frequency components of the satellite signal, the power spectrum density of each frequency point is calculated. P [ k ], and according to the power spectral density P [ k ] Calculate the dBm value and frequency value of each frequency point; The average power level of the background noise is calculated through 8192 sampling points of the satellite signal to obtain the background noise value of the satellite signal. P n .

4. The Starlink satellite capture and tracking method based on carrier-to-noise ratio according to claim 1, characterized in that: The calculation of the average power level of the nine strongest spectral lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal includes: Analyze the time-frequency domain frame structure of the Starlink downlink signal to determine the operating frequency band of the Starlink downlink signal; Arrange the 8192 sampling points of the current satellite signal in descending order according to the power level value, take the first 9 points as the 9 strongest spectral lines, and perform power level accumulation and average on the 9 strongest spectral lines to obtain the power level average value. : in, It represents the average value of the power level of the 9 strongest spectral lines; Indicates the power level of the spectral line with index i.

5. The Starlink satellite capture and tracking method based on carrier-to-noise ratio according to claim 1, characterized in that: The pre-configured spectrum analyzer parameters include: setting the sampling rate to 1 MHz, the center frequency to the corresponding intermediate frequency beacon frequency, the number of FFT transformation points to 8192; the intermediate frequency beacon frequency points include 1575 MHz, 1825 MHz, 1350 MHz and 1850 MHz.

6. A Starlink satellite capture and tracking device based on carrier-to-noise ratio, characterized in that: include: A data sampling module is used to sample satellite signals through a portable spectrum analyzer according to pre-configured spectrum analyzer parameters, obtain spectrum data corresponding to the satellite signals, and extract I / Q data from the spectrum data; A data preprocessing module is used to perform direct drift removal and windowing processing on the I / Q data to obtain a preprocessed satellite signal; A noise floor calculation module is used to perform FFT transformation on the pre-processed satellite signal, determine the frequency component of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency component; The spectrum shifting module is used to shift the negative frequency components in the spectrum data to the positive frequency components, and calculate the average power level of the nine strongest spectrum lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal; The carrier-to-noise ratio calculation module is used to calculate the carrier-to-noise ratio CNR of the Starlink satellite beacon signal based on the background noise value and the average power level of the 9 strongest spectral lines, and transmit the carrier-to-noise ratio CNR to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

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