A Method and Device for Starlink Satellite Acquisition and Tracking Based on Carrier-to-Noise Ratio

Abstract

The present invention provides a method and device for capturing and tracking Starlink satellites based on the carrier-to-noise ratio, belonging to the technical field of satellite dish alignment. The method samples satellite signals through a portable spectrum analyzer according to pre-configured spectrum analyzer parameters to obtain spectrum data, and extracts I / Q data from the spectrum data; performs DC offset removal and windowing processing on the I / Q data, performs FFT transformation on the pre-processed satellite signals to determine the frequency components of the satellite signals, and calculates the noise floor value of the satellite signals; then shifts the negative frequency components in the spectrum data to the positive frequency components, and calculates the average power level of the 9 strongest spectral lines in the Starlink downlink signal; finally, calculates the carrier-to-noise ratio CNR of the beacon signal according to the noise floor value and the average power level of the 9 strongest spectral lines, and transmits the carrier-to-noise ratio CNR to the antenna controller. By using the method of accumulating and averaging the beacon signal to calculate the carrier-to-noise ratio, the present invention can achieve the capture and stable tracking of Starlink satellites.

Description

Technical Field

[0001] The present invention relates to the technical field of satellite dish alignment, 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 all-weather, and can provide accurate position and navigation for military equipment. In addition to various functions such as communication, reconnaissance, and navigation, Starlink satellites also have certain application prospects. In terms of communication, by using the Starlink method, it can be applied to low Earth orbit to reach targets worldwide.

[0003] Currently, there is no Starlink service signal in China. We mainly rely on beacon signals to track Starlink satellites. However, these signals have fluctuations and instabilities, making it easy to lose signal connection using traditional tracking methods. To solve this problem, a new set of satellite capture and tracking methods needs to be developed to achieve the capture and stable tracking of Starlink satellites, so as to monitor their movement trajectories and keep track of their movements in real time. Summary of the Invention

[0004] In view of this, embodiments of the present invention provide a method and device for capturing and tracking Starlink satellites 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 as follows:

[0006] In a first aspect, the present invention provides a method for capturing and tracking Starlink satellites based on carrier-to-noise ratio, including:

[0007] Sampling satellite signals through a portable spectrum analyzer according to pre-configured spectrum analyzer parameters to obtain spectrum data corresponding to the satellite signals, and extracting I / Q data from the spectrum data;

[0008] Performing DC offset removal and windowing processing on the I / Q data to obtain preprocessed satellite signals;

[0009] Performing FFT transformation on the preprocessed satellite signals to determine the frequency components of the satellite signals, and calculating the noise floor value of the satellite signals based on the frequency components;

[0010] Shifting the negative frequency components in the spectrum data to the positive frequency components, and calculating 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;

[0011] 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 nine strongest spectral lines, and transmit the CNR to the antenna controller to control the antenna beam pointing to capture and track the Starlink satellite signal.

[0012] Further, the preprocessing of the I / Q data to obtain the preprocessed satellite signal includes:

[0013] Calculate the average value of the I / Q data:

[0014]

[0015] ,

[0016] where represents the Q value with index i, is the average value of the Q data, is the number of points set for the FFT transform; is the I value with index i, is the average value of the I data;

[0017] 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;

[0018] Based on the I / Q data after removing the DC offset, call the window function to generate the FlatTop window coefficient, and multiply each data point of the I / Q data by the FlatTop window coefficient to obtain the preprocessed satellite signal.

[0019] Further, the FFT transform of the preprocessed satellite signal is performed to determine the frequency components of the satellite signal, and the background noise value of the satellite signal is calculated based on the frequency components, including:

[0020] Copy the I / Q data in the preprocessed satellite signal to the FFTW library and input array;

[0021] Perform an FFT transform 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;

[0022] According to the frequency components of the satellite signal, calculate the power spectral density P k , and calculate the dBm value and frequency value of each frequency point according to the power spectral density P k ;

[0023] Calculate the average power level of the background noise through 8192 sampling points of the satellite signal to obtain the background noise value of the satellite signal P n ​​。

[0024] Further, calculating 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 includes:

[0025] Analyze the time-frequency domain frame structure of the Starlink downlink signal to determine the operating frequency band of the Starlink downlink signal;

[0026] 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 cumulative averaging of the power levels of the 9 strongest spectral lines to obtain the average power level. :

[0027]

[0028] Among them, represents the average value of the power levels of the 9 strongest spectral lines; represents the power level of the spectral line with index i.

[0029] Further, the pre-configured spectrum analyzer parameters include: setting the sampling rate to 1 MHz, the center frequency point to the corresponding intermediate frequency beacon frequency point, and the number of FFT transformation points to 8192; the intermediate frequency beacon frequency points include 1575 MHz, 1825 MHz, 1350 MHz, and 1850 MHz.

[0030] In a second aspect, the present invention provides a Starlink satellite acquisition and tracking device based on carrier-to-noise ratio, including:

[0031] A data sampling module, configured to sample the satellite signal through a portable spectrum analyzer according to the pre-configured spectrum analyzer parameters, obtain the spectrum data corresponding to the satellite signal, and extract I / Q data from the spectrum data;

[0032] A data preprocessing module, configured to perform DC offset removal and windowing processing on the I / Q data to obtain a preprocessed satellite signal;

[0033] A noise floor calculation module, configured to perform FFT transformation on the preprocessed satellite signal, determine the frequency components of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency components;

[0034] A spectrum shifting module, configured to shift 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;

[0035] The carrier-to-noise ratio calculation module is used to calculate the carrier-to-noise ratio CNR of the Starlink satellite beacon signal according to 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.

[0036] In summary, the beneficial effects of the present invention are as follows:

[0037] Through a method for capturing and tracking Starlink satellites based on the carrier-to-noise ratio provided by the present invention, the method first obtains I / Q data from a spectrum analyzer according to pre-configured spectrum analyzer parameters, and then performs DC offset removal and windowing processing on the I / Q data to make the spectrum clearer, reduce aliasing, and ensure the accuracy of signal processing. Then, an FFT transform is performed, the power spectral density is calculated and converted to dBm units, and then the spectral data is shifted to calculate the average power level of the Starlink downlink signal. The carrier-to-noise ratio SNR is calculated based on the power spectral density and the average power level and sent to the antenna controller to achieve the capture and stable tracking of the Starlink satellite. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings, and all of these are within the protection scope of the present invention.

[0039] Figure 1 It is a flowchart of a method for capturing and tracking Starlink satellites based on the carrier-to-noise ratio of the present invention;

[0040] Figure 2 It is a schematic diagram of the time-frequency domain frame structure of the Starlink downlink signal;

[0041] Figure 3 It is a functional module diagram of a device for capturing and tracking Starlink satellites based on the carrier-to-noise ratio according to an embodiment of the present invention;

[0042] Figure 4 It is an execution flowchart of a device for capturing and tracking Starlink satellites according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0043] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. If there is no conflict, the various features in the present invention and its embodiments can be combined with each other, and all are within the protection scope of the present invention.

[0044] The monitoring of Starlink satellites is crucial for national security because they can enhance military reconnaissance and communication capabilities, threaten national defense security, change the mode of warfare, challenge information sovereignty and regulation, threaten the security of space assets, and pose new challenges to space security. These satellites may exacerbate the arms race in outer space and have a profound impact on the global strategic balance.

[0045] In the country, since the coverage of Starlink service signals has not been implemented yet, we mainly rely on beacon signals to track Starlink satellites at present. However, the fluctuations and instabilities of these beacon signals have led to the easy interruption of traditional tracking technologies. The method of the present invention has been continuously tested and improved, perfectly solving this problem and achieving stable and continuous tracking of Starlink satellite signals. The detailed implementation process of the present invention is shown in the following embodiments.

[0046] Embodiment 1: Refer to Figure 1 as shown, Figure 1 is a flowchart of a method for capturing and tracking Starlink satellites based on the carrier-to-noise ratio of the present invention. Refer to Figure 1 as shown, a method for capturing and tracking Starlink satellites based on the carrier-to-noise ratio of the present invention, which is applied to the tracking and monitoring of Starlink satellites, the method includes:

[0047] Sampling satellite signals through a portable spectrum analyzer according to pre-configured spectrum analyzer parameters, obtaining spectrum data corresponding to the satellite signals, and extracting I / Q data from the spectrum data;

[0048] Performing DC offset removal and windowing processing on the I / Q data to obtain preprocessed satellite signals;

[0049] Performing FFT transformation on the preprocessed satellite signals, determining the frequency components of the satellite signals, and calculating the noise floor value of the satellite signals based on the frequency components;

[0050] Shifting the negative frequency components in the spectrum data to the positive frequency components, and calculating 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;

[0051] According to the background noise value and the average power level of the 9 strongest spectral lines, calculate the carrier-to-noise ratio CNR of the Starlink satellite beacon signal, 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.

[0052] Specifically, in the embodiment of the present invention, first obtain I data and Q data from the spectrum analyzer, then perform DC offset removal processing on the I data and Q data, perform windowing processing using the Flat Top function, and perform FFT transformation. Then calculate the power spectral density and convert it to the dBm unit, calculate the signal-to-noise ratio SNR and send it to the antenna controller.

[0053] Among them, the 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 radio frequency signal. The I / Q value refers to two complex components, namely the in-phase amplitude component In-phase (I) and Quadrature (Q). The I / Q value is 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 an I / Q value after frequency conversion, and then digital signal processing is performed on it. The I / Q value is also used to determine the phase and amplitude of the signal, so it is also widely used in radio communication and radar systems.

[0054] 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 point to the corresponding intermediate frequency beacon frequency point, and the number of points for FFT transformation to 8192. Among them, the intermediate frequency beacon frequency points include 1575 MHz, 1825 MHz, 1350 MHz, and 1850 MHz.

[0055] Further, in the embodiment of the present invention, performing DC offset removal and windowing processing on the I / Q data to obtain a preprocessed satellite signal specifically includes the following process:

[0056] DC offset removal is to improve the accuracy and reliability of the signal, avoid distortion in spectrum analysis, improve the dynamic range and performance of the system, ensure that weak signals are not submerged by the drift, and thus improve the effect of signal processing. Among them, the DC offset removal process is as follows:

[0057] Calculate the average value of the I / Q data:

[0058]

[0059] ,

[0060] Among them, represents the Q value with index i, is the average value of the Q data, is the number of points set for FFT transformation; The I value for index i is the average value of the I data.

[0061] 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.

[0062] Windowing is mainly to reduce the spectral leakage caused by signal truncation, reduce the discontinuity at the signal edge, reduce the edge effect, improve the spectral 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:

[0063] Based on the I / Q data after removing the DC offset, call the windowing function to generate the FlatTop window coefficients, and multiply each data point of the I / Q data by the FlatTop window coefficients to obtain the preprocessed satellite signal.

[0064] Among them, for a given window length n and window index i, the window coefficient w(i) of the FlatTop window can be calculated by the following formula:

[0065]

[0066] Where the coefficient a 0 , a 1 , a 2 , a 3 , a 4 The values of are respectively:

[0067] a 0 = 0.21557895;

[0068] a 1 = 0.41663158;

[0069] a 2 = 0.277263158;

[0070] a 3 = 0.083578947;

[0071] a 4 = 0.006947368;

[0072] Finally, apply the window coefficient to the Q data and I data. Multiply each data point by the window coefficient w(i) to obtain the preprocessed satellite signal.

[0073] Further, in the embodiments of the present invention, perform an FFT transform on the preprocessed 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. This process specifically includes:

[0074] Convert the signal from the time domain to the frequency domain for analyzing the frequency components of the signal. Specifically, first copy the I / Q data in the preprocessed satellite signal to the FFTW library and input it into the array.

[0075] Perform an FFT transform 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.

[0076] For a sequence x[n] of length N, its discrete Fourier transform (DFT) is defined as:

[0077]

[0078] Where: X k is the sequence x n 's k-th DFT coefficient; x n is the input array; k is the frequency index, with a value range from 0 to N -1; j is the imaginary unit, satisfying j² = -1. The discrete Fourier transform (DFT) is a form in which the Fourier transform is discrete in both the time domain and the frequency domain, transforming the sampling of the time-domain signal into the sampling in the frequency domain of the discrete-time Fourier transform (DTFT). The discrete Fourier transform is the N-point equally spaced sampling of the spectrum of the sequence x(n) on [0, 2π], that is, the discretization of the spectrum of the sequence.

[0079] Among them, the present invention uses the fast Fourier transform (FFT) to transform the data. Therefore, the present invention uses the FFTW library for data transformation. FFTW is a high-performance fast Fourier transform (FFT) library written in C language, supporting various types of data transformations, including complex numbers, real numbers, symmetric, and multi-dimensional transformations. This library can efficiently process data sets of any size.

[0080] According to the frequency components of the satellite signal, calculate the power spectral density P k at each frequency point, and calculate the dBm value and frequency value at each frequency point according to the power spectral density P k . ​​​​​

[0081] Specifically, when calculating the power spectral density (PSD) at each frequency point, the square of the modulus of the DFT is divided by the length N of the signal and the sampling period , to obtain the power spectral density P k :

[0082]

[0083] Then, calculate the dBm value and frequency value at each frequency point. Among them, dBm represents the unit of the absolute value of power, which is used to describe the strength and power level of the signal.

[0084] Finally, through 8192 sampling points of the spectrum analyzer, calculate the average power level of the background noise to obtain the background noise value of the satellite signal P n :[[]]END]]

[0085] .

[0086] Due to the large number of sampling points, even if the power levels of several spectral lines are relatively high, after calculating the average value of all points, the background noise will be relatively close to the average value. Therefore, we believe that P n is the background noise value.

[0087] Specifically, in the embodiment of the present invention, the spectral data is shifted so that the negative frequency part is moved to the positive frequency part, which can make the spectral data more intuitive and easier to process, and simplify the subsequent spectral analysis and visualization work. For example, assuming that the number of sampling points is 8, and the initial values of the dBm array are [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 spectral shifting, it becomes [e, f, g, h, a, b, c, d].[[]]END]]

[0088] Furthermore, in the embodiment of the present invention, based on the time-frequency domain frame structure of the Starlink downlink signal, calculate the average power level of the 9 strongest spectral lines in the Starlink downlink signal. The specific process includes:

[0089] Analyze the time-frequency domain frame structure of the Starlink downlink signal to determine the working frequency band of the Starlink downlink signal.

[0090] Among them, the time-frequency domain frame structure of the Starlink downlink signal refers to Figure 2 shown in the figure. In the figure f represents the frequency, t represents the period, PSS represents the primary synchronization signal, OFDM represents the OFDM symbol, T f ​Indicates the frame period. Analyzing the time-frequency domain frame structure of the Starlink downlink signal, it can be known that the downlink signal operates in the Ku band of 10.7~12.7 GHz. There are a total of 8 channels with a bandwidth of 250 MHz. Each channel consists of a signal effective bandwidth of 240 MHz and a guard interval of 10 MHz. The narrowband part is composed of 9 single-tone signals. The frequency interval between adjacent signals is equal, approximately 44 kHz. The signals are located at the center frequency, exactly within the frequency band gap of the broadband signal. The main function of the single-tone signal is to act as a beacon signal to represent the presence of the satellite, providing a basis for the ground receiving terminal to search for and track the satellite. The 9 single-tone signals of Starlink are concentrated within a 1 MHz bandwidth centered at the center frequency. The ground terminal can detect the presence of the Starlink downlink signal by using a relatively small capture bandwidth. If there is a Starlink downlink signal, it will surely be among the 9 strongest spectral lines. Therefore, we can take out the power levels of the 9 strongest spectral lines, accumulate and average them, and then estimate the carrier-to-noise ratio to determine whether there is a Starlink signal currently.

[0091] 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 averaging on the 9 strongest spectral lines to obtain the average power level :

[0092]

[0093] Among them, represents the average value of the power levels of the 9 strongest spectral lines; represents the power level of the spectral line with index i.

[0094] Specifically, after calculating the noise floor value and the average power level of the 9 strongest spectral lines in the embodiments of the present invention, the carrier-to-noise ratio (CNR) can be calculated and sent to the antenna controller. This process specifically includes:

[0095] (1) According to the formula CNR = 10log( P s / P n ), calculate the carrier-to-noise ratio of the beacon signal. Through testing, it is found that when there is a Starlink satellite beacon signal, the calculated carrier-to-noise ratio is about 20 dB.

[0096] (2) Transmit the carrier-to-noise ratio CNR to the antenna controller through the serial port. The antenna controller controls the pointing of the beam to achieve dynamic tracking of the antenna.

[0097] The antenna controller determines whether the current satellite signal is successfully captured according to the CNR value. If the capture is successful, it continues to track; otherwise, it continues to scan.

[0098] At present, there is no effective method in China to continuously and stably track Starlink satellites. Due to the fluctuations and instabilities of beacon signals, traditional methods are prone to losing signal connection. To solve this problem, the embodiments of the present invention have developed a method for capturing and tracking Starlink satellites using carrier-to-noise ratio information. This method calculates the carrier-to-noise ratio by accumulating and averaging beacon signals, and can achieve the capture and stable tracking of Starlink satellites. Through testing and verification, it is found that when a traditional electronic phased array antenna tracks the beacon signal of a Starlink satellite, its effective elevation angle range is limited to plus or minus 60 degrees. By adopting this method and using a variable inclination continuous transverse section array (VICTS) antenna, the tracking range can be effectively extended, and the elevation angle can reach 15 degrees to 90 degrees. Therefore, the combination of this new method and the use of a VICTS antenna can significantly improve the tracking stability of Starlink satellite signals and reduce the risk of signal loss.

[0099] Embodiment 2: Refer to Figure 3 As shown in the figure, on the basis of Embodiment 1, the embodiment of the present invention further provides a Starlink satellite capture and tracking device based on carrier-to-noise ratio. The device includes:

[0100] A data sampling module, configured 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;

[0101] A data preprocessing module, configured to perform DC drift removal and windowing processing on the I / Q data to obtain preprocessed satellite signals;

[0102] A noise floor calculation module, configured to perform FFT transformation on the preprocessed satellite signals, determine the frequency components of the satellite signals, and calculate the noise floor value of the satellite signals based on the frequency components;

[0103] A spectrum shifting module, configured to shift the negative frequency components in the spectrum data to 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;

[0104] A carrier-to-noise ratio calculation module, configured to calculate the carrier-to-noise ratio CNR of the Starlink satellite beacon signal according to the noise floor 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 direction to capture and track the Starlink satellite signals.

[0105] Specifically, refer to Figure 4The device execution process shown is as follows. After configuring the parameters of the spectrum analyzer, the star chain satellite capture and tracking device in the embodiment of the present invention calculates the carrier-to-noise ratio (CNR) through two 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 I / Q data, perform DC offset removal and windowing processing, calculate the CNR, and send it to the antenna controller.

[0106] 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 them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and 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 component of the satellite signal, and calculate the noise floor value of the satellite signal based on the frequency component, including: copying the I / Q data in the pre-processed satellite signal to the FFTW library and inputting it into the array; performing FFT transformation on the array to transform the pre-processed satellite signal from the time domain to the frequency domain to determine the frequency component of the satellite signal; calculating the power spectrum density of each frequency point based on the frequency component of the satellite signal P [ k ], and according to the power spectral density P [ k ] Calculate the dBm value and frequency value of each frequency point; calculate the average power level of the background noise through 8192 sampling points of the satellite signal to obtain the background noise value of the satellite signal P n ; The negative frequency components in the spectrum data are moved to the positive frequency components, and the power level average of the 9 strongest spectral lines in the Starlink downlink signal is calculated based on the time-frequency domain frame structure of the Starlink downlink signal, including: analyzing the time-frequency domain frame structure of the Starlink downlink signal to determine the working frequency band of the Starlink downlink signal; arranging the 8192 sampling points of the current satellite signal in descending order according to the power level value, taking the first 9 points as the 9 strongest spectral lines, and accumulating and averaging the power levels of the 9 strongest spectral lines to obtain the power level average : in, It represents the average value of the power level of the 9 strongest spectral lines; represents the power level of the spectral line with index i; 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 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.

4. 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; The 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, including: copying the I / Q data in the pre-processed satellite signal to the FFTW library and inputting it into the array; performing FFT transformation on the array, transforming the pre-processed satellite signal from the time domain to the frequency domain, and determining the frequency component of the satellite signal; calculating the power spectrum density of each frequency point based on the frequency component of the satellite signal P [ k ], and according to the power spectral density P [ k ] Calculate the dBm value and frequency value of each frequency point; calculate the average power level of the background noise through 8192 sampling points of the satellite signal to obtain the background noise value of the satellite signal P n ; The spectrum shifting module is used to shift the negative frequency components in the spectrum data to the positive frequency components, and calculate the power level average of the 9 strongest spectral lines in the Starlink downlink signal based on the time-frequency domain frame structure of the Starlink downlink signal, including: analyzing the time-frequency domain frame structure of the Starlink downlink signal to determine the working frequency band of the Starlink downlink signal; arranging the 8192 sampling points of the current satellite signal in descending order according to the power level value, taking the first 9 points as the 9 strongest spectral lines, and accumulating and averaging the power levels of 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; represents the power level of the spectral line with index i; 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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