A method for acquiring and processing radar signals from external radiation sources

Abstract

This invention discloses a method for acquiring and processing radar signals from external radiation sources, belonging to the field of radar signal processing technology. It is applicable to various external radiation source radar signals, possesses strong versatility, and boasts high acquisition and processing efficiency. The method includes: determining target signal association parameters corresponding to the application scenario; selecting a suitable positioning method for acquiring and processing external radiation source radar signals based on a comparison between the target signal association parameters and their respective preset association parameter thresholds; acquiring external radiation source radar signals using the positioning method to obtain multi-channel signal data corresponding to the positioning method; and processing the multi-channel signal data to obtain the detection and positioning results of the external radiation source radar signals.

Description

Technical Field

[0001] This invention relates to the field of radar signal processing technology, and in particular to a method for acquiring and processing radar signals from external radiation sources. Background Technology

[0002] External radiation source radar refers to a system that does not radiate electromagnetic signals itself, but rather detects targets by utilizing the electromagnetic signals reflected from them. It is similar to traditional bistatic / multistatic radar, but differs in that it lacks a transmitter; instead, it utilizes existing civilian signals in space. It has attracted widespread attention due to its advantages such as high concealment, low power consumption, strong anti-interference capabilities, and long operating range. Technological advancements have led to the generation of increasingly more civilian signals. Following broadcast signals, television signals, second- and third-generation wireless communication signals such as GSM and CDMA, and GPS have emerged, providing more possibilities for external radiation source detection systems to find suitable external radiation sources. However, because the signal processing algorithms of external radiation source radar are more complex than those of traditional radar, and the signal bandwidth is larger (sampling rates typically exceeding 10MHz), and the clutter suppression algorithms used in signal processing are more complex, external radiation source radar processes a larger amount of data and requires more computation. This places a significant demand on data processing capabilities.

[0003] In existing technologies, the positioning methods for acquiring and processing radar signals from external radiation sources cannot adapt to different application scenarios and have poor versatility. Summary of the Invention

[0004] Based on the above analysis, the embodiments of the present invention aim to provide a method for acquiring and processing radar signals from external radiation sources, which is applicable to various external radiation source radar signals, has strong versatility, and has high acquisition and processing efficiency.

[0005] This invention discloses a method for acquiring and processing radar signals from external radiation sources, comprising:

[0006] Determine the target signal association parameters corresponding to the application scenario;

[0007] Based on the comparison results between the target signal correlation parameters and their respective preset correlation parameter thresholds, the corresponding positioning method for external radiation source radar signal acquisition and processing is selected.

[0008] The aforementioned positioning method is used to collect radar signals from external radiation sources, thereby obtaining multi-channel signal data corresponding to the positioning method. The multi-channel signal data is then processed to obtain the detection and positioning results of the radar signals from external radiation sources.

[0009] Furthermore, determining the target signal association parameters corresponding to the application scenario includes:

[0010] The target signal correlation parameters corresponding to the first application scenario are determined to be the number of external radiation source radar signals and the quality parameters of the external radiation source radar signals.

[0011] The target signal correlation parameters corresponding to the second application scenario are determined to be the number of direct wave receiving channels and the number of echo signal receiving channels.

[0012] Further, if the application scenario is the first application scenario; accordingly, the step of selecting the corresponding positioning method for external radiation source radar signal acquisition and processing based on the comparison result between the target signal association parameters and their respective corresponding preset association parameter thresholds includes:

[0013] If the number of external radiation source radar signals is greater than or equal to 2, and at least 2 of the external radiation source radar signals have quality parameters greater than or equal to the preset external radiation source radar signal quality parameter threshold, then the corresponding external radiation source radar signal acquisition and processing positioning method is selected as time difference positioning method.

[0014] If fewer than two of the external radiation source radar signal quality parameters are greater than or equal to the preset external radiation source radar signal quality parameter threshold, then the corresponding external radiation source radar signal acquisition and processing positioning method is selected as the direction finding-time difference joint positioning method.

[0015] Further, if the application scenario is the second application scenario; accordingly, the step of selecting the corresponding positioning method for external radiation source radar signal acquisition and processing based on the comparison result between the target signal association parameters and their respective corresponding preset association parameter thresholds includes:

[0016] If the number of direct wave receiving channels is greater than or equal to 2, and the number of echo signal receiving channels is greater than or equal to 2, then the corresponding external radiation source radar signal acquisition and processing positioning method is time difference positioning.

[0017] If the number of direct wave receiving channels is equal to 1 and the number of echo signal receiving channels is greater than or equal to 3, then the corresponding external radiation source radar signal acquisition and processing positioning method is the direction finding-time difference joint positioning method.

[0018] Furthermore, the step of using the positioning method to collect radar signals from external radiation sources to obtain multi-channel signal data corresponding to the positioning method includes:

[0019] The multi-channel signal data corresponding to the time difference positioning method obtained are two direct wave signal data and two echo signal data;

[0020] The multi-channel signal data corresponding to the direction finding-time difference joint positioning method obtained are one direct wave signal data and three echo signal data.

[0021] Further, the processing of the multi-channel signal data to obtain the detection and location results of the external radiation source radar signal includes:

[0022] A target positioning algorithm corresponding to the positioning method is determined, and the multi-channel signal data is processed according to the target positioning algorithm to obtain the detection and positioning result of the external radiation source radar signal.

[0023] Further, the step of determining the target positioning algorithm corresponding to the positioning method includes:

[0024] The target localization algorithm corresponding to the time difference positioning method is determined to be the time difference estimation algorithm using two stations;

[0025] The target localization algorithm corresponding to the direction finding-time difference joint positioning method is determined to be a combined algorithm; the combined algorithm is an algorithm that combines the target azimuth estimation algorithm obtained by array direction finding with the time difference estimation algorithm using dual stations.

[0026] Further, the processing of the multi-channel signal data to obtain the detection and location results of the external radiation source radar signal includes:

[0027] The data required for detection and positioning is extracted from the multi-channel signal data by solving the echo signal.

[0028] Segmented pulse compression is performed on the data required for detection and positioning;

[0029] Migration correction is performed on the segmented pulse compressed signal;

[0030] The migration-corrected signal is subjected to range-Doppler processing to obtain the detection and localization results.

[0031] Furthermore, prior to the step of solving for the data required for detection and positioning from the multi-channel signal data using echo signals, the external radiation source radar signal acquisition and processing method further includes:

[0032] The signal acquisition and processing parameters of the multi-channel signal data are initialized.

[0033] Free up storage space;

[0034] The initialization of signal acquisition and processing parameters includes:

[0035] Allocate memory and video memory, and distribute cache.

[0036] Further, the range-Doppler processing of the migration-corrected signal to obtain the detection and localization result includes:

[0037] The processing result obtained from the distance-Doppler processing in the GPU is sent to the CPU. The CPU detects and locates the processing result to obtain the detection and location result.

[0038] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0039] The present invention provides a method for acquiring and processing external radiation source radar signals. This method determines target signal association parameters corresponding to the application scenario; selects a suitable positioning method for external radiation source radar signal acquisition and processing based on a comparison between the target signal association parameters and their respective preset association parameter thresholds; acquires external radiation source radar signals using the positioning method to obtain multi-channel signal data corresponding to the positioning method; and processes the multi-channel signal data to obtain the detection and positioning results of the external radiation source radar signals. This method has strong versatility and high acquisition and processing efficiency.

[0040] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0041] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0042] Figure 1 This is a flowchart of the external radiation source radar signal acquisition and processing method in an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram illustrating the selection of positioning methods in an embodiment of the present invention;

[0044] Figure 3 This is a schematic diagram illustrating the process of a workstation processing multi-channel signal data in an embodiment of the present invention. Detailed Implementation

[0045] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0046] A specific embodiment of the present invention discloses a method for acquiring and processing radar signals from an external radiation source, the flowchart of which is shown below. Figure 1 As shown, it includes the following steps:

[0047] Step S1: Determine the target signal association parameters corresponding to the application scenario.

[0048] Step S2: Based on the comparison results between the target signal association parameters and their respective preset association parameter thresholds, select the appropriate positioning method for external radiation source radar signal acquisition and processing.

[0049] Step S3: Use the positioning method to collect external radiation source radar signals to obtain multi-channel signal data corresponding to the positioning method, and process the multi-channel signal data to obtain the detection and positioning results of the external radiation source radar signals.

[0050] In step 1 above, the application scenarios may include a first application scenario and a second application scenario.

[0051] The first application scenario includes detecting external radiation source radar signals; the second application scenario includes detecting pre-deployed direct wave receiving antennas and echo signal receiving antennas.

[0052] Furthermore, the target signal association parameters corresponding to the first application scenario are determined to be the number of external radiation source radar signals and the external radiation source radar signal quality parameters; in order to achieve the purpose of detecting and locating the target position, the number of external radiation source radar signals is at least one. The target position refers to the location of the target detected by the external radiation source radar.

[0053] Signal quality parameters of external radiation source radar can include signal-to-noise ratio (SNR), which measures the quality of the external radiation source radar signal. The higher the SNR value, the better the signal quality of the external radiation source radar; the lower the SNR value, the worse the signal quality of the external radiation source radar.

[0054] The target signal association parameters corresponding to the second application scenario are determined to be the number of direct wave receiving channels and the number of echo signal receiving channels. In order to achieve the purpose of detecting and locating the target position, the number of direct wave receiving channels is at least 1, the number of echo signal receiving channels is at least 2, and the total number of direct wave receiving channels and echo signal receiving channels is at least 4.

[0055] In step 2 above, for the first application scenario:

[0056] The preset correlation parameter threshold corresponding to the number of external radiation source radar signals is 2; the preset correlation parameter threshold corresponding to the external radiation source radar signal quality parameter is the preset signal quality parameter threshold, and the external radiation source radar signal quality parameter can be specifically the signal-to-noise ratio, and the preset signal quality parameter threshold can be specifically the preset signal-to-noise ratio threshold.

[0057] If the number of external radiation source radar signals is greater than or equal to two, and at least two of the external radiation source radar signals have quality parameters greater than or equal to a preset external radiation source radar signal quality parameter threshold, then the corresponding external radiation source radar signal acquisition and processing positioning method is time difference positioning. That is, when there are at least two radiation source radar signals with good signal quality, the positioning method is time difference positioning; including the following situations:

[0058] When there are two external radiation source radar signals, and the quality parameters of these two external radiation source radar signals are both greater than or equal to the radiation source radar signal quality parameter threshold.

[0059] When there are 3 or more external radiation source radar signals, the quality parameters of 2 or more of these external radiation source radar signals are greater than or equal to the radiation source radar signal quality parameter threshold.

[0060] If the quality parameters of fewer than two external radiation source radar signals are greater than or equal to a preset external radiation source radar signal quality parameter threshold, then the corresponding external radiation source radar signal acquisition and processing positioning method is the direction-finding-time difference joint positioning method. That is, if there is one radiation source radar signal or no signal with good quality, then the positioning method is the direction-finding-time difference joint positioning method, including the following situations:

[0061] When the number of external radiation source radar signals is equal to one or more, but only one external radiation source radar signal has a quality parameter greater than or equal to the radiation source radar signal quality parameter threshold.

[0062] When the number of external radiation source radar signals is equal to 1 or more, but no external radiation source radar signal has a quality parameter greater than or equal to the radiation source radar signal quality parameter threshold.

[0063] Among them, the time difference positioning method and the direction finding-time difference joint positioning method are existing positioning methods, and will not be described in detail.

[0064] For the second application scenario:

[0065] The preset correlation parameter threshold corresponding to the number of direct wave receiving channels is 2; the preset correlation parameter threshold corresponding to the number of echo signal receiving channels can be determined based on the preset correlation parameter threshold corresponding to the number of direct wave receiving channels, and can be 2 or 3, so that the total number of direct wave receiving channels and echo signal receiving channels is at least 4.

[0066] If the number of direct wave receiving channels is greater than or equal to 2, and the number of echo signal receiving channels is greater than or equal to 2, then the corresponding external radiation source radar signal acquisition and processing positioning method is time difference positioning.

[0067] If the number of direct wave receiving channels is 1 and the number of echo signal receiving channels is 3 or more, then the corresponding external radiation source radar signal acquisition and processing positioning method is the direction finding-time difference joint positioning method. It should be noted that: if the number of direct wave receiving channels is 1, then the preset correlation parameter threshold corresponding to the number of echo signal receiving channels is set to 3; if the number of direct wave receiving channels is 2 or more, then the preset correlation parameter threshold corresponding to the number of echo signal receiving channels is set to 2.

[0068] In step 3, to ensure the normal acquisition of external radiation source radar signals, a multi-channel software-defined radio receiver can be used to acquire these signals. The operating parameters of the multi-channel software-defined radio receiver need to be set. That is, the step of acquiring external radiation source radar signals using the aforementioned positioning method and obtaining multi-channel signal data corresponding to that positioning method can be performed within the multi-channel software-defined radio receiver.

[0069] The operating parameters of a multi-channel software-defined radio receiver can be set at the workstation. Since acquiring two-dimensional target positioning results requires at least two sets of time difference estimates for time difference positioning, or direction finding-time difference joint positioning using angle estimates from three array antennas and one time difference estimate, a multi-channel software-defined radio receiver is required to have at least four channels for simultaneous reception. The operating parameters of the radio receiver include, but are not limited to, the carrier frequency of the external radiation source signal, the multi-channel local oscillator sharing mode, the receiver's GPS selection, the signal sampling rate, the acquisition bandwidth, the acquisition duration, and the channel receiving gain.

[0070] Furthermore, such as Figure 2 As shown, the positioning method is used to collect radar signals from external radiation sources, obtaining multi-channel signal data corresponding to the positioning method, including:

[0071] The multi-channel signal data corresponding to the time difference positioning method obtained are two direct wave signal data and two echo signal data;

[0072] The multi-channel signal data corresponding to the direction-finding-time difference (TDD) joint positioning method obtained consists of one direct wave signal and three echo signal data. The multi-channel software-defined radio receiver is equipped with a signal data acquisition module, which can acquire signals from external radiating source radars. Specifically, under the set operating parameters, the signals received by the receiving antenna array of the external radiating source radar are synchronously acquired through multiple channels to obtain multi-channel signal data. To obtain the target positioning result, if the TDD positioning method is selected, two direct wave signal data and two echo signal data are required; if the direction-finding-TDD joint positioning method is selected, one direct wave signal data and three echo signal data are required.

[0073] Furthermore, such as Figure 2 and Figure 3 As shown, this step can be performed on a workstation, which includes a CPU and a GPU. The processing of the multi-channel signal data to obtain the detection and localization results of the external radiation source radar signal includes:

[0074] A target positioning algorithm corresponding to the positioning method is determined, and the multi-channel signal data is processed according to the target positioning algorithm to obtain the detection and positioning result of the external radiation source radar signal.

[0075] Further, the step of determining the target positioning algorithm corresponding to the positioning method includes:

[0076] The target localization algorithm corresponding to the time difference positioning method is determined to be the time difference estimation algorithm using two stations; the time difference estimation algorithm using two stations is an existing algorithm.

[0077] The target localization algorithm corresponding to the direction-finding-time difference (TDD) joint positioning method is determined to be a combined algorithm. This combined algorithm combines the target azimuth estimation algorithm obtained from array direction finding with the TDD estimation algorithm using dual stations. Since the positioning effect of the direction-finding-TDD joint positioning method is not as good as that of the TDD positioning method, a combined algorithm is adopted to make the positioning of the direction-finding-TDD joint positioning method more accurate. The target azimuth estimation algorithm obtained from array direction finding is an existing algorithm.

[0078] Furthermore, such as Figure 3 As shown, the process of processing the multi-channel signal data to obtain the detection and location results of the external radiation source radar signal includes:

[0079] The echo signal is used to solve for the data needed for target detection and localization from the multi-channel signal data. The purpose of echo signal solving is to extract the data needed for target detection and localization from a large amount of redundant signal data. In specific implementation, the Extended Cancellation Algorithm-B (ECA-B) can be used to perform clutter suppression processing on one reference signal data and multiple echo signal data in parallel. First, a sliding matrix is ​​constructed, and then the echo signal is solved. Since the echo signal solving mainly includes a series of matrix operations such as matrix multiplication and matrix inversion, it can be completed using APIs in libraries such as cuBLAS.

[0080] The data required for detection and positioning is segmented into pulses and compressed. Segmented pulse compression can reduce computational load by using signal segmentation, fast time-dimensional signal FFT, conjugate multiplication, and slow time-dimensional filtering and decimation. Signal segmentation and slow time-dimensional filtering and decimation are implemented using kernel functions, while fast time-dimensional signal FFT and conjugate multiplication can be implemented by calling APIs from libraries such as cuFFT.

[0081] Migration correction is performed on the segmented pulse compressed signal. First, the segmented pulse compressed signal is subjected to slow-time dimensional windowing and slow-time CZT transform. The slow-time dimensional windowing can be implemented by reading coefficients pre-stored in the video memory.

[0082] The coefficients required for CZT can be stored in GPU memory and accessed later, which speeds up computation. Then, IFFT is performed on the slower time dimension to complete the migration correction.

[0083] The migration-corrected signal is then subjected to range-Doppler processing to obtain the detection and localization results. Range-Doppler processing can be achieved through IFFT of the fast-time dimension signal and FFT of the slow-time dimension signal.

[0084] Furthermore, the processing result obtained from the distance-Doppler processing in the GPU is sent to the CPU, where the CPU detects and locates the processing result to obtain the detection and location result.

[0085] After the GPU accelerates the above complex algorithms, it sends the processing results back to the CPU, which then performs subsequent detection, localization, and display control functions.

[0086] Furthermore, such as Figure 3 As shown, before the step of solving the problem from the multi-channel signal data using echo signals and extracting the data required for detection and positioning, the external radiation source radar signal acquisition and processing method further includes:

[0087] The signal acquisition and processing parameters of the multi-channel signal data are initialized.

[0088] Free up storage space;

[0089] The initialization of signal acquisition and processing parameters includes:

[0090] Allocate memory and video memory, and distribute cache. These steps can be performed on the CPU.

[0091] Compared with existing technologies, the external radiation source radar signal acquisition and processing method provided by this invention determines the target signal association parameters corresponding to the application scenario; selects the appropriate positioning method for external radiation source radar signal acquisition and processing based on the comparison results of the target signal association parameters and their respective preset association parameter thresholds; acquires external radiation source radar signals using the positioning method to obtain multi-channel signal data corresponding to the positioning method; and processes the multi-channel signal data to obtain the detection and positioning results of the external radiation source radar signal. It has strong versatility and high acquisition and processing efficiency.

[0092] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0093] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for acquiring and processing radar signals from an external radiation source, characterized in that, include: Determine the target signal association parameters corresponding to the application scenario; Based on the comparison results between the target signal correlation parameters and their respective preset correlation parameter thresholds, the corresponding positioning method for external radiation source radar signal acquisition and processing is selected. If the application scenario is the first application scenario, then the step of selecting the appropriate positioning method for external radiation source radar signal acquisition and processing based on the comparison result between the target signal association parameters and their respective preset association parameter thresholds includes: If the number of external radiation source radar signals is greater than or equal to 2, and at least 2 of the external radiation source radar signals have quality parameters greater than or equal to the preset external radiation source radar signal quality parameter threshold, then the corresponding external radiation source radar signal acquisition and processing positioning method is selected as time difference positioning method. If less than two of the external radiation source radar signal quality parameters are greater than or equal to the preset external radiation source radar signal quality parameter threshold, then the corresponding external radiation source radar signal acquisition and processing positioning method is the direction finding-time difference joint positioning method. If the application scenario is the second application scenario, then the step of selecting the appropriate positioning method for external radiation source radar signal acquisition and processing based on the comparison result between the target signal association parameters and their respective preset association parameter thresholds includes: If the number of direct wave receiving channels is greater than or equal to 2, and the number of echo signal receiving channels is greater than or equal to 2, then the corresponding external radiation source radar signal acquisition and processing positioning method is time difference positioning. If the number of direct wave receiving channels is equal to 1 and the number of echo signal receiving channels is greater than or equal to 3, then the corresponding external radiation source radar signal acquisition and processing positioning method is the direction finding-time difference joint positioning method. The aforementioned positioning method is used to collect radar signals from external radiation sources, thereby obtaining multi-channel signal data corresponding to the positioning method. The multi-channel signal data is then processed to obtain the detection and positioning results of the radar signals from external radiation sources.

2. The method for acquiring and processing radar signals from external radiation sources according to claim 1, characterized in that, The method of acquiring radar signals from external radiation sources using the aforementioned positioning method to obtain multi-channel signal data corresponding to the positioning method includes: The multi-channel signal data corresponding to the time difference positioning method obtained are two direct wave signal data and two echo signal data; The multi-channel signal data corresponding to the direction finding-time difference joint positioning method obtained are one direct wave signal data and three echo signal data.

3. The method for acquiring and processing radar signals from external radiation sources according to claim 1, characterized in that, The process of processing the multi-channel signal data to obtain the detection and location results of the external radiation source radar signal includes: A target positioning algorithm corresponding to the positioning method is determined, and the multi-channel signal data is processed according to the target positioning algorithm to obtain the detection and positioning result of the external radiation source radar signal.

4. The method for acquiring and processing radar signals from external radiation sources according to claim 3, characterized in that, The algorithm for determining the target positioning method includes: The target localization algorithm corresponding to the time difference positioning method is determined to be the time difference estimation algorithm using two stations; The target localization algorithm corresponding to the direction finding-time difference joint positioning method is determined to be a combined algorithm; the combined algorithm is an algorithm that combines the target azimuth estimation algorithm obtained by array direction finding with the time difference estimation algorithm using dual stations.

5. The method for acquiring and processing radar signals from external radiation sources according to claim 1, characterized in that, The process of processing the multi-channel signal data to obtain the detection and location results of the external radiation source radar signal includes: The data required for detection and positioning is extracted from the multi-channel signal data by solving the echo signal. Segmented pulse compression is performed on the data required for detection and positioning; Migration correction is performed on the segmented pulse compressed signal; The migration-corrected signal is subjected to range-Doppler processing to obtain the detection and positioning results.

6. The method for acquiring and processing radar signals from external radiation sources according to claim 5, characterized in that, Before the step of solving the problem from the multi-channel signal data using echo signals and extracting the data required for detection and positioning, the external radiation source radar signal acquisition and processing method further includes: The signal acquisition and processing parameters of the multi-channel signal data are initialized. Free up storage space; The initialization of signal acquisition and processing parameters includes: Allocate memory and video memory, and distribute cache.

7. The method for acquiring and processing radar signals from external radiation sources according to claim 5, characterized in that, The migration-corrected signal is subjected to range-Doppler processing to obtain the detection and localization results, including: The processing result obtained from the distance-Doppler processing in the GPU is sent to the CPU. The CPU detects and locates the processing result to obtain the detection and location result.

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