Radar signal processing method and system based on dual-mode adaptive clutter map

Abstract

The invention relates to the technical field of radar signal processing, and particularly provides a radar signal processing method and system based on a dual-mode adaptive clutter map. An iteration strategy emphasizing historical data and an iteration strategy emphasizing current data are respectively designed for the static clutter map and the dynamic clutter map, so that the static clutter background is kept stable, and meanwhile, the dynamic clutter can be quickly tracked; and further combining a static clutter weighting curve fitted based on an MTD improvement factor and a moving clutter weighting curve fitted according to environmental noise to generate adaptive detection thresholds, thereby effectively avoiding over-suppression of a real target while remarkably suppressing various clutters. The method can greatly reduce the false alarm rate in a complex environment, guarantees the stable detection of a real target, and has good system real-time performance.

Description

Technical Field

[0001] This invention relates to the field of radar signal processing technology, and in particular to a radar signal processing method and system based on dual-mode adaptive clutter maps. Background Technology

[0002] Clutter mapping is a technique used in radar to suppress clutter and detect real targets. It establishes a spatiotemporal distribution model of background clutter by recording historical detection data, thereby enabling adaptive threshold adjustment of the clutter region during detection.

[0003] However, existing clutter mapping techniques typically suffer from several shortcomings: First, they employ a single iterative strategy: traditional clutter maps use fixed iterative weights to fuse historical and current data. The spatiotemporal characteristics of static clutter (such as mountains and buildings) and dynamic clutter (such as clouds, rain, and flocks of birds) differ significantly. A single iterative strategy cannot simultaneously optimize the suppression of both. If the weights are biased towards historical data, static clutter suppression is good, but tracking rapidly changing dynamic clutter is difficult; if the weights are biased towards current data, dynamic clutter tracking is good, but the static clutter background is unstable. Second, threshold settings are imprecise: existing technologies use simple threshold settings that fail to fully consider the variations in the radar system's own improvement factors across different Doppler channels, resulting in inaccurate suppression effects, either with numerous false alarms or the easy deletion of real targets. Third, real-time challenges: a complete clutter map requires enormous storage and computational resources; how to efficiently implement it in a real-time radar signal processing system is a major challenge.

[0004] Therefore, there is an urgent need in this field for an efficient clutter map processing scheme that can adaptively distinguish and effectively suppress static clutter and dynamic clutter, and significantly reduce the false alarm rate of the entire system. Summary of the Invention

[0005] This invention provides a radar signal processing method and system based on dual-mode adaptive clutter maps to address the shortcomings of existing technologies.

[0006] On one hand, the present invention provides a radar signal processing method based on dual-mode adaptive clutter maps, comprising: The radar echo signal generated by the radar system is acquired, and the radar echo signal is processed by pulse compression and moving target detection to obtain signal data of multiple Doppler channels corresponding to each range gate. Based on the signal data, static clutter diagrams and dynamic clutter diagrams are established; The standard static clutter map is obtained by updating the static clutter map using the data from the first preset channel in the Doppler channel and the first iterative weight; The standard dynamic clutter map is obtained by using data from the second preset channel in the Doppler channel and updating the dynamic clutter map with the second iterative weight; the first iterative weight is greater than the second iterative weight. The static clutter suppression threshold is calculated based on the standard static clutter diagram and the static clutter weighted curve fitted with the MTD improvement factor curve. Based on the standard dynamic clutter diagram and the preset dynamic clutter weighted curve, the dynamic clutter suppression threshold is calculated. Based on the static clutter suppression threshold and the dynamic clutter suppression threshold, the signal data of each distance gate and each Doppler channel are detected and judged, and the target point is output.

[0007] Optionally, using data from the first preset channel in the Doppler channel and updating the static clutter map with a first iterative weight, a standard static clutter map is obtained, including: Extract the first velocity channel and the second velocity channel of the distance gate. First signal data of the speed channel; The first signal data is input into the first iterative formula for iterative calculation to obtain a standard static clutter diagram; Among them, the The number of distance gate speed channels; The first iterative formula is: ; in, For standard static clutter diagrams, For historical static clutter data, For the first signal data, The weights of the first iteration and .

[0008] Optionally, the dynamic clutter map is updated using data from the second preset channel in the Doppler channel and a second iterative weight to obtain a standard dynamic clutter map, including: Extracting the distance gate located at the first The first channel to the first Second signal data for one or more intermediate speed channels within a channel range; The second signal data is input into the second iterative formula for iterative calculation to obtain the standard dynamic clutter diagram; The second iterative formula is: ; in, For standard dynamic clutter diagrams, 2 represents the historical dynamic clutter data. 2 represents the second signal data. The weights for the second iteration and .

[0009] Optionally, the static clutter suppression threshold is calculated based on the standard static clutter plot and the static clutter weighted curve fitted based on the MTD improvement factor curve, including: The data in the standard static clutter diagram are multiplied by the corresponding data points of the static clutter weighted curve fitted based on the MTD improvement factor curve to obtain the first intermediate data. The first intermediate data is added to the preset static clutter threshold factor to obtain the static clutter suppression threshold.

[0010] Optionally, based on the standard dynamic clutter diagram and a preset dynamic clutter weighted curve, a dynamic clutter suppression threshold is calculated, including: The data in the standard dynamic clutter diagram are multiplied by the corresponding data points of the preset dynamic clutter weighted curve to obtain the second intermediate data; The second intermediate data is added to the preset dynamic clutter threshold factor to obtain the dynamic clutter suppression threshold.

[0011] Optionally, based on the static clutter suppression threshold and the dynamic clutter suppression threshold, the signal data of each range gate and each Doppler channel are detected and decided, and the target point is output, including: Amplitude extraction processing is performed on the signal data of each distance gate and each Doppler channel to obtain the amplitude value of the corresponding signal data; The amplitude value is compared with the static clutter suppression threshold and the dynamic clutter suppression threshold corresponding to the distance gate and the Doppler channel, respectively, to obtain the comparison result; Based on the comparison results, the signal data that meets the preset conditions is analyzed to obtain the target point.

[0012] Optionally, based on the comparison results, the signal data that meets the preset conditions is analyzed to obtain the target point trace, including: If the comparison result shows that the amplitude value is lower than both the static clutter suppression threshold and the dynamic clutter suppression threshold, then the signal data is determined to be a clutter signal. If the comparison result shows that the amplitude value is higher than the static clutter suppression threshold or the dynamic clutter suppression threshold, then the signal data is determined to be a suspected target signal; The suspected target signals are subjected to range dimension aggregation processing. By merging the similar suspected target signals within adjacent range gates, the denoised candidate target signals are obtained. The candidate target signals are subjected to characteristic verification and amplitude stability verification processing. The candidate target signals that meet the preset continuous frame number requirements and amplitude fluctuation threshold range are retained to obtain the real target signals. The real target signal is processed by information parsing to extract the distance and velocity parameters of the real target signal and generate target traces.

[0013] Optionally, it also includes: Allocate storage space for the static clutter map and the dynamic clutter map; When updating the static clutter map and the dynamic clutter map, historical static clutter map data and / or historical dynamic clutter map data of the corresponding azimuth angle are read from the storage space for iterative calculation; The updated data of the standard static clutter map and the data of the standard dynamic clutter map are written back to the storage space as the data of the historical static clutter map and the data of the historical dynamic clutter map.

[0014] Optionally, it also includes: Acquire background noise data of the radar system in a targetless environment; Based on the background noise data, calculate the average noise level within the Doppler channel range; Based on the ratio of radar signal to the average noise level, a dynamic clutter weighted curve is generated by fitting.

[0015] On the other hand, the present invention also provides a radar signal processing system based on a dual-mode adaptive clutter map, comprising: The signal acquisition module is configured to acquire radar echo signals generated by the radar system, and to perform pulse compression and moving target detection processing on the radar echo signals to obtain signal data of multiple Doppler channels corresponding to each range gate. The clutter map creation and update module is configured to create static clutter maps and dynamic clutter maps based on the signal data; The standard static clutter map is obtained by updating the static clutter map using the data from the first preset channel in the Doppler channel and the first iterative weight; The standard dynamic clutter map is obtained by using data from the second preset channel in the Doppler channel and updating the dynamic clutter map with the second iterative weight; the first iterative weight is greater than the second iterative weight. The threshold calculation module is configured to calculate the static clutter suppression threshold based on the standard static clutter diagram and the static clutter weighted curve fitted with the MTD improvement factor curve. Based on the standard dynamic clutter diagram and the preset dynamic clutter weighted curve, the dynamic clutter suppression threshold is calculated. The detection and decision module is configured to detect and decide on the signal data of each distance gate and each Doppler channel according to the static clutter suppression threshold and the dynamic clutter suppression threshold, and output the target point trace.

[0016] On the other hand, the present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the radar signal processing method based on dual-mode adaptive clutter map as described above.

[0017] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the radar signal processing method based on dual-mode adaptive clutter map as described above.

[0018] On the other hand, the present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the radar signal processing method based on dual-mode adaptive clutter map as described above.

[0019] This invention provides a radar signal processing method and system based on dual-mode adaptive clutter maps. The method establishes static and dynamic clutter maps in parallel, and designs iterative strategies that emphasize historical data and current data for the static and dynamic clutter maps respectively. This stabilizes the static clutter background while enabling rapid tracking of dynamic clutter. Furthermore, it combines a static clutter weighted curve fitted based on the MTD improvement factor and a dynamic clutter weighted curve fitted based on environmental noise to generate adaptive detection thresholds. This significantly suppresses various types of clutter while effectively avoiding over-suppression of real targets. The method can significantly reduce the false alarm rate in complex environments, ensure stable detection of real targets, and possesses good system real-time performance. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating the radar signal processing method based on dual-mode adaptive clutter map provided in an embodiment of the present invention. Figure 2 This is a schematic diagram of the standard static clutter map creation method provided in the embodiments of the present invention; Figure 3 This is a schematic diagram of the standard dynamic clutter diagram establishment method provided in the embodiments of the present invention; Figure 4 This is a schematic diagram of the static clutter suppression threshold calculation provided in an embodiment of the present invention; Figure 5This is a schematic diagram of dynamic clutter suppression threshold calculation provided in an embodiment of the present invention; Figure 6 This is a normal detection effect diagram provided by an embodiment of the present invention; Figure 7 This is a detection effect diagram of the radar signal processing method based on dual-mode adaptive clutter map provided in the embodiments of the present invention; Figure 8 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] The following is combined Figures 1-7 This invention describes a radar signal processing method based on a dual-mode adaptive clutter map.

[0024] Figure 1 This is a schematic flowchart of the radar signal processing method based on dual-mode adaptive clutter map provided in an embodiment of the present invention.

[0025] like Figure 1 As shown in the embodiment of the present invention, the radar signal processing method based on dual-mode adaptive clutter map mainly includes the following steps: 101. Acquire radar echo signals generated by the radar system, and perform pulse compression and moving target detection processing on the radar echo signals to obtain signal data of multiple Doppler channels corresponding to each range gate.

[0026] Specifically, the radar system acquires radar echo signals formed by the reflection of high-frequency electromagnetic waves emitted by the radar system into the detection airspace through the transmitting antenna. The radar echo signals include the reflected signals of the real target, the static clutter signals generated by ground objects, and the dynamic clutter signals generated by clouds, rain, and flocks of birds, while also being superimposed with the radar system's own noise and environmental noise.

[0027] Therefore, pulse compression and target detection processing are required for the radar echo signal. First, pulse compression processing is performed on the acquired radar echo signal. This is done by convolving the received echo pulse with the transmitted pulse using a matched filter function, compressing the signal pulse width, improving the radar's range resolution, and thus distinguishing signal components at different range positions to obtain a discretely distributed range-gated signal in the range dimension.

[0028] Subsequently, moving target detection processing is performed on the signal of each range gate. The time domain signal is converted to the frequency domain by Fourier transform to achieve Doppler frequency shift separation of the signal, thereby obtaining the signal data of multiple Doppler channels corresponding to each range gate. The signal data includes signal information of different velocity components, providing a basic data source for the subsequent establishment and updating of static clutter maps and dynamic clutter maps.

[0029] 102. Based on signal data, establish static clutter diagrams and dynamic clutter diagrams.

[0030] Specifically, based on the signal data from multiple Doppler channels corresponding to each range gate, static clutter maps and dynamic clutter maps are constructed respectively. The static clutter map mainly reflects clutter information generated by relatively stationary ground features, while the dynamic clutter map is used to describe dynamic clutter information such as clouds, rain, and flocks of birds.

[0031] 103. Use the data from the first preset channel in the Doppler channel and update the static clutter map using the first iterative weight to obtain the standard static clutter map.

[0032] Specifically, the static clutter map is updated using data from the first preset channel in the Doppler channel and the first iterative weighting to obtain a standard static clutter map, including: Extracting the first velocity channel and the second velocity channel of the distance gate First signal data of the speed channel; The first signal data is input into the first iterative formula for iterative calculation to obtain the standard static clutter diagram; in, The number of distance gate speed channels; The formula for the first iteration is: ; in, For standard static clutter diagrams, For historical static clutter data, For the first signal data, The weights of the first iteration and .

[0033] Among them, such as Figure 2 As shown, the first preset channel is the first speed channel and the acc channel of each distance gate. The first preset channel is selected based on the unreliability of zero-velocity channel information when the radar is in DC-free mode, enabling accurate capture of the characteristic information of static clutter such as ground objects and buildings; based on the first preset channel, the first velocity channel and the first acceleration channel are extracted from the signal data of each range gate. The signal data from the first velocity channel is used as the first signal data for updating the static clutter diagram. During the extraction process, the distance gate identifier corresponding to the data is recorded simultaneously to ensure that the correspondence between the data and the distance gate is accurate.

[0034] Subsequently, the historical static clutter map data corresponding to the current azimuth angle is retrieved from the storage module. The historical static clutter map data is the static clutter map data updated during the signal processing of the previous frame. Its data structure is consistent with the static clutter map to be updated now, that is, the row dimension corresponds to the distance gate and the column dimension corresponds to the static clutter feature parameters.

[0035] Next, the extracted first signal data and the historical static clutter map data retrieved Substituting the preset first iteration formula into the equation, iterative calculations are performed to obtain the standard static clutter map output after iterative updates. The weights of the first iteration and This weighting setting is biased towards historical data, which can ensure the stability of the background of static clutter maps and thus accurately characterize the spatiotemporal distribution characteristics of static ground clutter.

[0036] In the specific calculation process, for each distance gate, the historical data and the current first signal data are weighted and fused point by point according to the above formula to ensure that the static clutter characteristics of each distance gate can be accurately updated.

[0037] After iterative calculations are completed, the generated standard static clutter map fully preserves the stable characteristics of historical static clutter while incorporating the latest information on current static clutter. This provides accurate and stable basic data support for subsequent static clutter suppression threshold calculations. Furthermore, the standard static clutter map is written back to the storage module in real time as historical static clutter map data for the next frame of signal processing. .

[0038] 104. Using the data from the second preset channel in the Doppler channel and updating the dynamic clutter map with the second iterative weight, a standard dynamic clutter map is obtained.

[0039] In this case, the weight of the first iteration is greater than the weight of the second iteration.

[0040] Specifically, the standard dynamic clutter map is obtained by using data from the second preset channel in the Doppler channel and updating the dynamic clutter map using the second iterative weight, including: Extraction distance gate is located at the first The first channel to the first Second signal data for one or more intermediate speed channels within a channel range; The second signal data is input into the second iterative formula for iterative calculation to obtain the standard dynamic clutter diagram; The second iteration formula is: ; in, For standard dynamic clutter diagrams, 2 represents the historical dynamic clutter data. 2 represents the second signal data. The weights for the second iteration and .

[0041] Among them, such as Figure 3 As shown, the selection range of the second preset channel is based on the total number of Doppler channels (acc), and the intermediate velocity channel interval of each distance gate is determined as the [missing information]. The first channel to the first The middle speed channel can avoid static clutter interference near zero speed and accurately capture the dynamic characteristics of moving clutter such as clouds, rain, flocks of birds, and environmental noise.

[0042] Based on the detection accuracy requirements of the radar system, signal data from one or more intermediate velocity channels can be selected from the intermediate velocity channel range. If multiple channels are selected, average processing is performed on multiple channels to smooth the random noise fluctuations of individual channels, ultimately obtaining the second signal data corresponding to each range gate. 2.

[0043] Subsequently, historical dynamic clutter map data corresponding to the current azimuth angle is retrieved from the storage module. 2. Historical dynamic clutter data 2 represents the dynamic clutter map data updated and stored after processing the previous frame's signal. Its matrix structure is similar to the dynamic clutter map data to be updated currently. Figure 1 This provides a historical feature reference for iterative updates.

[0044] Next, the processed second signal data 2. Historical dynamic clutter data 2. Substitute the values ​​into the preset second iteration formula and perform point-by-point weighted fusion calculation. The weights for the second iteration and This weight setting is biased towards the current data, enabling the dynamic clutter map to quickly respond to real-time changes in dynamic clutter and accurately track the dynamic distribution pattern of dynamic clutter.

[0045] During the calculation process, for each distance gate, the historical data and the current second signal data are processed element by element according to the formula to ensure that the dynamic clutter characteristics of each distance gate can be updated in real time.

[0046] After the iterative calculation is completed, the generated standard dynamic clutter map not only retains the historical trend of dynamic clutter changes, but also fully integrates the latest dynamic information of current dynamic clutter, providing reliable data support for the accurate calculation of subsequent dynamic clutter suppression thresholds. At the same time, the standard dynamic clutter map is written back to the storage module in real time as historical dynamic clutter map data for the next frame of signal processing. 2. Ensure the continuity of iterative updates.

[0047] 105. The static clutter suppression threshold is calculated based on the standard static clutter diagram and the static clutter weighted curve fitted by the MTD improvement factor curve.

[0048] Among them, such as Figure 4 As shown, based on the standard static clutter plot and the static clutter weighted curve fitted with the MTD improvement factor curve, the static clutter suppression threshold is calculated, including: The data in the standard static clutter plot are multiplied by the corresponding data points of the static clutter weighted curve fitted based on the MTD improvement factor curve to obtain the first intermediate data. The first intermediate data is added to the preset static clutter threshold factor to obtain the static clutter suppression threshold.

[0049] Specifically, the system retrieves standard static clutter data, which is stored in matrix form. The row dimension corresponds to each range gate detected by the radar, and the column dimension corresponds to the static clutter characteristic parameters. At the same time, it calls the preset static clutter weighted curve parameters. The static clutter weighted curve parameters are generated by fitting the MTD (moving target detection) improvement factor curve of the radar system. Its core feature is to assign high weights near zero velocity and gradually reduce the weights in the channel region far from zero velocity. This design can effectively prevent large static targets from raising the overall noise level of the corresponding range gate and avoid generating false targets carrying abnormal velocity components.

[0050] Subsequently, using the range gate and Doppler channel as indices, the value of each range gate-channel unit in the standard static clutter map is multiplied point-by-point with the weight value of the static clutter weighted curve at the corresponding Doppler channel position. For example, for the first velocity channel data of the nth range gate, the high weight value of the static clutter weighted curve at that channel position is matched to complete the multiplication operation, ensuring that the suppression weights of the static clutter concentration area are matched. Through point-by-point multiplication, the first intermediate data that can reflect the priority of static clutter suppression is obtained. The data dimension of the first intermediate data is consistent with the standard static clutter map, and the value of each unit integrates the inherent characteristics of static clutter and the channel suppression weight.

[0051] Finally, a preset static clutter threshold factor is introduced. The static clutter threshold factor is a fixed threshold obtained by calibration based on the radar system noise level, detection sensitivity requirements and actual application scenarios. It is used to compensate for possible suppression deviations after weighted calculation.

[0052] The value of each unit in the first intermediate data is added point by point to the static clutter threshold factor. That is, through the operation logic of the first intermediate data plus the static clutter threshold factor, the static clutter suppression threshold corresponding to each distance gate-channel unit is finally obtained. The static clutter suppression threshold can adaptively match the distribution characteristics of static clutter, forming a higher suppression threshold in areas with dense static clutter, and maintaining a reasonable threshold in areas with no static clutter or weak static clutter.

[0053] 106. Based on the standard dynamic clutter diagram and the preset dynamic clutter weighted curve, the dynamic clutter suppression threshold is calculated.

[0054] Among them, such as Figure 5 As shown, based on the standard dynamic clutter diagram and the preset dynamic clutter weighted curve, the dynamic clutter suppression threshold is calculated, including: The data in the standard dynamic clutter diagram are multiplied by the corresponding data points of the preset dynamic clutter weighted curve to obtain the second intermediate data; The second intermediate data is added to the preset dynamic clutter threshold factor to obtain the dynamic clutter suppression threshold.

[0055] Specifically, the data of the standard dynamic clutter map is retrieved. This data is stored in matrix form, with the row dimension corresponding to each range gate detected by the radar and the column dimension corresponding to the dynamic clutter dynamic characteristic parameters. It can characterize the real-time distribution and changing characteristics of dynamic clutter such as clouds, rain, and flocks of birds.

[0056] At the same time, the preset dynamic clutter weighted curve parameters are called. The dynamic clutter weighted curve parameters are flat curves. The generation logic of the dynamic clutter weighted curve parameters is to first evaluate the average noise level of the middle Doppler channel, and then fit it by calculating the ratio of signal to noise.

[0057] Subsequently, using the range gate and Doppler channel as dual indices, multiplication operations are performed on the standard dynamic clutter map data and the dynamic clutter weighted curve for corresponding data points. Specifically, for the value of each range gate-channel unit in the standard dynamic clutter map, the weight value of the dynamic clutter weighted curve at the corresponding Doppler channel position is matched, and the multiplication process is completed point by point. For example, for the m-th range gate... to The intermediate velocity channel data within the interval is used to calculate the smooth weight value of the dynamic clutter weighted curve at that channel position, resulting in second intermediate data that integrates the inherent characteristics of dynamic clutter and uniform suppression weight.

[0058] Finally, a preset dynamic clutter threshold factor is introduced. The dynamic clutter threshold factor is a fixed threshold obtained by calibration based on the radar system environmental noise baseline, dynamic clutter intensity statistics, and target detection probability requirements. It is used to compensate for the possible insufficient or excessive suppression problems after weighted calculation. The value of each unit in the second intermediate data is added to the dynamic clutter threshold factor point by point. That is, through the calculation logic of the second intermediate data + dynamic clutter threshold factor, the dynamic clutter suppression threshold corresponding to each range gate-channel unit is finally obtained.

[0059] 107. Based on the static clutter suppression threshold and the dynamic clutter suppression threshold, detect and decide the signal data of each distance gate and each Doppler channel, and output the target point trace.

[0060] Specifically, based on the static clutter suppression threshold and the dynamic clutter suppression threshold, the signal data of each range gate and each Doppler channel are detected and judged, and the target point trace is output, including: Amplitude extraction processing is performed on the signal data of each distance gate and each Doppler channel to obtain the amplitude value of the corresponding signal data.

[0061] In this process, amplitude extraction processing is performed on the signal data of each range gate and each Doppler channel. This can be achieved by calculating the magnitude of the signal data of each range gate-Doppler channel, removing irrelevant information such as signal phase interference, and obtaining the amplitude value corresponding to each signal data. The amplitude value reflects the strength of the signal at the corresponding position.

[0062] The amplitude values ​​are compared with the static clutter suppression thresholds and dynamic clutter suppression thresholds corresponding to the distance gate and Doppler channel, respectively, to obtain the comparison results.

[0063] The method uses both the range gate and the Doppler channel as dual indices, comparing the amplitude values ​​one-to-one with the pre-calculated static clutter suppression thresholds and dynamic clutter suppression thresholds under each index. During the comparison, the positional correspondence of the data is maintained; that is, the amplitude value of the i-th range gate and the j-th Doppler channel is compared only with the static clutter suppression threshold and dynamic clutter suppression threshold corresponding to that position. By determining the relationship between the amplitude value and the two thresholds, a comparison result is generated, ensuring accurate feature determination for each signal unit.

[0064] Based on the comparison results, the signal data that meets the preset conditions is analyzed to obtain the target point.

[0065] Based on the comparison results, signal data that meets preset conditions is analyzed to obtain target points, including: If the comparison result shows that the amplitude value is lower than both the static clutter suppression threshold and the dynamic clutter suppression threshold, then the signal data is determined to be a clutter signal. If the comparison result shows that the amplitude value is higher than the static clutter suppression threshold or the dynamic clutter suppression threshold, then the signal data is determined to be a suspected target signal. Range-dimensional aggregation processing is performed on the suspected target signals. By merging the similar suspected target signals within adjacent range gates, the denoised candidate target signals are obtained. The candidate target signals are subjected to characteristic verification and amplitude stability verification. The candidate target signals that meet the preset duration frame requirements and amplitude fluctuation threshold range are retained to obtain the real target signals. The system performs information parsing and processing on the real target signal to extract the distance and velocity parameters of the real target signal and generate target traces.

[0066] Specifically, based on the comparison results of the amplitude value and the dual thresholds, the signal data of each range gate-Doppler channel are classified and judged. If the comparison result shows that the signal amplitude value is lower than both the static clutter suppression threshold and the dynamic clutter suppression threshold, the signal data is judged to be invalid clutter signals such as ground object static clutter or cloud and rain dynamic clutter, and is directly suppressed and removed to avoid interfering with target detection; if the comparison result shows that the signal amplitude value is higher than the static clutter suppression threshold or the dynamic clutter suppression threshold, the signal data is judged to be a suspected target signal, and the range, channel index and amplitude information corresponding to the suspected target signal are retained.

[0067] For all signals identified as suspected targets, range-dimensional aggregation processing is performed. Specifically, based on the radar's range resolution, an adjacent range gate threshold is set. Correlation analysis is conducted on spatially adjacent suspected target signals. If suspected signals within adjacent range gates originate from the same target, i.e., satisfying the criteria of amplitude continuity and channel consistency, they are merged into a single signal unit. Simultaneously, isolated suspected signals without any adjacent correlation are eliminated. Through range-dimensional aggregation processing, denoised candidate target signals are obtained, effectively reducing the proportion of false points.

[0068] The denoised candidate target signal undergoes dual verification. Dual verification involves two aspects: firstly, characteristic verification, which sets a preset duration frame requirement to retain only candidate target signals that persist across multiple frames, eliminating transient interference signals that occasionally appear within a single frame; secondly, amplitude stability verification, which sets a preset amplitude fluctuation threshold range, for example, the difference between the maximum and minimum amplitude values ​​should not exceed 30% of the mean. If the difference exceeds 30%, candidate signals with abrupt amplitude changes or irregular fluctuations are eliminated. Finally, the signal that simultaneously meets both the duration requirement and the amplitude stability requirement is retained to obtain the true target signal.

[0069] After obtaining the real target signal, information parsing processing is performed on the real target signal. Based on the range gate index corresponding to the real target signal and combined with the range calibration parameters of the radar system, the range information of the real target is calculated. Based on the Doppler channel index corresponding to the real target signal and combined with the mapping relationship between Doppler frequency shift and velocity, the velocity information of the real target is calculated. The range and velocity parameter information, signal amplitude, and frame identifier are integrated with the data according to a preset data format to generate a target trace that includes the real target detection information.

[0070] In some embodiments, the radar signal processing method based on dual-mode adaptive clutter maps provided in this invention further includes: Allocate storage space for static and dynamic clutter maps; When updating the static clutter map and the dynamic clutter map, the historical static clutter map data and / or historical dynamic clutter map data of the corresponding azimuth angle are read from the storage space for iterative calculation; The updated standard static clutter data and standard dynamic clutter data are written back to the storage space as historical static clutter data and historical dynamic clutter data.

[0071] Specifically, during the power-on initialization phase of the radar system, based on the radar's detection range, number of range gates, total number of Doppler channels (acc), and clutter map data accuracy requirements, independent storage spaces are allocated in the storage module for static clutter maps and dynamic clutter maps respectively. The matrix dimensions of the two storage spaces are matched with the radar detection parameter space to ensure that clutter map data under each azimuth angle can be stored completely.

[0072] In the clutter map update stage of each frame of signal processing, the historical static clutter map data corresponding to the current azimuth angle detected by the radar is first read from the preset storage space based on the azimuth angle information detected by the radar. and historical dynamic clutter data and historical static clutter image data and historical dynamic clutter data The corresponding iterative calculation units are input respectively, and together with the extracted first signal data and second signal data, the standard static clutter map and the standard dynamic clutter map are updated iteratively.

[0073] After the iterative calculation is completed, the radar system immediately writes the updated standard static clutter map data and standard dynamic clutter map data back to the corresponding dedicated storage space of the storage module in real time according to the original azimuth index, overwriting the original historical data. This makes the new clutter map data the historical reference data for the next frame of signal processing, forming a closed-loop storage mechanism of read-update-write-back. This ensures both the continuity of clutter map iterative updates and data consistency, and meets the real-time requirements of radar signal processing through the efficient read and write performance of the storage module.

[0074] In some embodiments, the radar signal processing method based on dual-mode adaptive clutter maps provided in this invention further includes: Acquire background noise data of the radar system in a targetless environment; Calculate the average noise level within the Doppler channel range based on background noise data; Based on the ratio of radar signal to average noise level, a dynamic clutter weighted curve is generated by fitting.

[0075] Specifically, before the radar system officially begins target detection, the radar is first controlled to be in a clean environment free from interference from real targets. The background noise signal is continuously collected within a preset time period through the radar receiving antenna. After pulse compression and moving target detection (MTD) processing, the background noise data of all Doppler channels corresponding to each range gate is obtained to ensure that the data can fully reflect the inherent noise of the radar system and the background noise characteristics of the environment.

[0076] Based on the collected background noise data, for the intermediate velocity channel interval of each distance gate, the average noise level within the Doppler channel range corresponding to each distance gate is obtained by calculating the arithmetic mean or root mean square value of the noise data of all channels within the intermediate velocity channel interval, thus eliminating the deviation caused by the noise fluctuation of a single channel. Subsequently, based on the signal detection strength standard preset by the radar system, the ratio of radar signal to corresponding average noise level at different Doppler channel positions is calculated. A data distribution model is established with the Doppler channel number as the abscissa and the signal-to-noise ratio as the ordinate. The data distribution model is then fitted with a curve using the least squares method, and finally a clutter weighted curve with an amplitude fluctuation range not exceeding ±10% is generated.

[0077] like Figure 6 and Figure 7 As shown, Figure 6 The image shows the detection effect of the radar signal processing method based on dual-mode adaptive clutter map provided in the embodiments of the present invention without using the method described in the embodiments of the present invention. Figure 7 The image shows the detection effect of the radar signal processing method based on dual-mode adaptive clutter map provided in the embodiments of the present invention.

[0078] Depend on Figure 6 and Figure 7 The comparison shows that, Figure 6 In the middle, a large number of dense blue dots (corresponding to static and dynamic clutter signals) exist in the range of distance 0 to 2000m and speed 0 to 120m / s. The clutter covers part of the area and easily interferes with the identification of real targets; while Figure 7In the process, the number of clutter points in the original dense clutter area is greatly reduced, especially in the static clutter concentration area at a distance of 0-2000m and a speed of 0-100m / s. Excess clutter points are effectively filtered out, and only a small number of discrete points corresponding to real targets are retained. The distinction between targets and clutter is significantly improved, and the accuracy of radar detection of real targets is effectively enhanced.

[0079] Based on the same inventive concept, this invention also protects a radar signal processing system based on a dual-mode adaptive clutter map. The radar signal processing system based on a dual-mode adaptive clutter map provided by this invention will be described below. The radar signal processing system based on a dual-mode adaptive clutter map described below can be referred to in correspondence with the radar signal processing method based on a dual-mode adaptive clutter map described above.

[0080] In some embodiments, the present invention also provides a radar signal processing system based on a dual-mode adaptive clutter map, comprising: The signal acquisition module is configured to acquire radar echo signals generated by the radar system, and to perform pulse compression and moving target detection processing on the radar echo signals to obtain signal data of multiple Doppler channels corresponding to each range gate. The clutter map creation and update module is configured to create static clutter maps and dynamic clutter maps based on signal data. The standard static clutter map is obtained by updating the static clutter map using the data from the first preset channel in the Doppler channel and the first iterative weight; The standard dynamic clutter map is obtained by using data from the second preset channel in the Doppler channel and updating the dynamic clutter map with the second iteration weight; the first iteration weight is greater than the second iteration weight. The threshold calculation module is configured to calculate the static clutter suppression threshold based on the standard static clutter diagram and the static clutter weighted curve fitted with the MTD improvement factor curve. Based on the standard dynamic clutter diagram and the preset dynamic clutter weighted curve, the dynamic clutter suppression threshold is calculated. The detection and decision module is configured to detect and decide on the signal data of each range gate and each Doppler channel based on the static clutter suppression threshold and the dynamic clutter suppression threshold, and output the target point trace.

[0081] Figure 8 This is a schematic diagram of the structure of the electronic device provided in an embodiment of the present invention.

[0082] like Figure 8As shown, the electronic device may include a processor 810, a communications interface 820, a memory 830, and a communication bus 840. The processor 810, communications interface 820, and memory 830 communicate with each other via the communication bus 840. The processor 810 can call logical instructions from the memory 830 to execute a radar signal processing method based on a dual-mode adaptive clutter map.

[0083] Furthermore, the logical instructions in the aforementioned memory 830 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0084] On the other hand, the present invention also provides a computer program product, which includes a computer program that can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer is able to execute the radar signal processing method based on dual-mode adaptive clutter map provided by the above methods.

[0085] In another aspect, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the radar signal processing method based on dual-mode adaptive clutter map provided by the above methods.

[0086] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0087] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of radar signal processing based on a dual-mode adaptive clutter map, characterized in that, The method comprises the following steps: acquiring radar echo signals generated by a radar system, and performing pulse compression and moving target detection processing on the radar echo signals to obtain signal data of multiple Doppler channels corresponding to each range gate; based on the signal data, establishing a static clutter map and a moving clutter map; updating the static clutter map using data of a first preset channel in the Doppler channels and adopting a first iteration weight to obtain a standard static clutter map; updating the moving clutter map using data of a second preset channel in the Doppler channels and adopting a second iteration weight to obtain a standard moving clutter map; the first iteration weight is greater than the second iteration weight; calculating a static clutter suppression threshold according to the standard static clutter map and a static clutter weighting curve fitted based on an MTD improvement factor curve; calculating a moving clutter suppression threshold according to the standard moving clutter map and a preset moving clutter weighting curve; performing detection judgment on the signal data of each range gate and each Doppler channel according to the static clutter suppression threshold and the moving clutter suppression threshold, and outputting a target track.

2. The dual-mode adaptive clutter map based radar signal processing method of claim 1, wherein, updating the static clutter map using data of a first preset channel in the Doppler channels and adopting a first iteration weight to obtain a standard static clutter map comprises: extracting first signal data of a first velocity channel of the range gate and a second velocity channel of the range gate inputting the first signal data into a first iteration formula for iteration calculation to obtain the standard static clutter map; wherein the is the number of distance gate velocity channels; the first iteration formula is: ； wherein, is a standard clutter map, is data of a historical clutter map, is first signal data, is a first iteration weight and .

3. The dual-mode adaptive clutter map based radar signal processing method of claim 2, wherein, updating the moving clutter map using data of a second preset channel in the Doppler channels and adopting a second iteration weight to obtain a standard moving clutter map comprises: extracting second signal data for one or more intermediate velocity channels in a range of the first channel to the second channel in which the distance gate is located ​​ inputting the second signal data into a second iteration formula for iteration calculation to obtain the standard moving clutter map; the second iteration formula is: ； wherein is a standard motion clutter map, 2 is data of a historical motion clutter map, 2 is second signal data, is a second iteration weight and .

4. The dual-mode adaptive clutter map based radar signal processing method of claim 1, wherein, calculating a static clutter suppression threshold according to the standard static clutter map and a static clutter weighting curve fitted based on an MTD improvement factor curve comprises: performing multiplication operation on corresponding data points of data in the standard static clutter map and the static clutter weighting curve fitted based on the MTD improvement factor curve to obtain first intermediate data; adding the first intermediate data and a preset static clutter threshold factor to obtain the static clutter suppression threshold.

5. The dual-mode adaptive clutter map based radar signal processing method of claim 1, wherein, calculating a moving clutter suppression threshold according to the standard moving clutter map and a preset moving clutter weighting curve comprises: performing multiplication operation on corresponding data points of data in the standard moving clutter map and the preset moving clutter weighting curve to obtain second intermediate data; adding the second intermediate data and a preset moving clutter threshold factor to obtain the moving clutter suppression threshold.

6. The dual-mode adaptive clutter map based radar signal processing method of claim 1, wherein, performing detection judgment on the signal data of each range gate and each Doppler channel according to the static clutter suppression threshold and the moving clutter suppression threshold, and outputting a target track comprises: performing amplitude extraction processing on the signal data of each range gate and each Doppler channel to obtain amplitude values of the corresponding signal data; performing comparison processing on the amplitude values and the static clutter suppression threshold and the moving clutter suppression threshold corresponding to the corresponding range gate and Doppler channel to obtain comparison results; analyzing signal data satisfying a preset condition according to the comparison results to obtain a target track.

7. The dual-mode adaptive clutter map based radar signal processing method of claim 6, wherein, analyzing signal data satisfying a preset condition according to the comparison results to obtain a target track comprises: If the comparison result is that the amplitude value is lower than both the static clutter suppression threshold and the moving clutter suppression threshold, it is determined that the signal data is a clutter signal; If the comparison result is that the amplitude value is higher than the static clutter suppression threshold or the moving clutter suppression threshold, it is determined that the signal data is a suspected target signal; Performing distance dimension condensation processing on the suspected target signal, and obtaining a denoised candidate target signal by merging homologous suspected target signals within adjacent distance gates; Performing characteristic verification and amplitude stability checking processing on the candidate target signal, and retaining the candidate target signal that meets the preset continuous frame number requirement and the amplitude fluctuation threshold range to obtain a real target signal; Performing information analysis processing on the real target signal, extracting the distance and speed parameter information of the real target signal, and generating a target track.

8. The dual-mode adaptive clutter map based radar signal processing method of claim 2, wherein, Further comprising: allocating storage space for the static clutter map and the moving clutter map; when updating the static clutter map and the moving clutter map, reading historical static clutter map data and / or historical moving clutter map data corresponding to the bearing angle from the storage space to perform iterative calculation; writing the data of the updated standard static clutter map and the data of the standard moving clutter map back to the storage space as the data of the historical static clutter map and the data of the historical moving clutter map.

9. The dual-mode adaptive clutter map based radar signal processing method of claim 1, wherein, Further comprising: obtaining background noise data of a radar system in a target-free environment; based on the background noise data, calculating the average noise level in the Doppler channel range; according to the ratio relationship between the radar signal and the average noise level, fitting to generate a moving clutter weighting curve.

10. A radar signal processing system based on a dual-mode adaptive clutter map, characterized by, Comprising: a signal acquisition module configured to acquire radar echo signals generated by a radar system, and perform pulse compression and moving target detection processing on the radar echo signals to obtain signal data of a plurality of Doppler channels corresponding to each distance gate; a clutter map establishing and updating module configured to establish a static clutter map and a moving clutter map based on the signal data; updating the static clutter map using the data of a first preset channel in the Doppler channels and adopting a first iterative weight to obtain a standard static clutter map; updating the moving clutter map using the data of a second preset channel in the Doppler channels and adopting a second iterative weight to obtain a standard moving clutter map; the first iterative weight is greater than the second iterative weight; a threshold calculation module configured to calculate a static clutter suppression threshold according to the standard static clutter map and a static clutter weighting curve fitted based on an MTD improvement factor curve; calculate a moving clutter suppression threshold according to the standard moving clutter map and a preset moving clutter weighting curve; a detection decision module configured to perform detection decision on the signal data of each distance gate and each Doppler channel according to the static clutter suppression threshold and the moving clutter suppression threshold, and output a target track.

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