Radar signal processing method and system, terminal, medium and program product

Abstract

The invention discloses a radar signal processing method and system, a terminal, a medium and a program product, and relates to the field of radar signal processing. When detecting that the intermediate-frequency echo signal contains a clutter signal, performing MTD processing on the intermediate-frequency echo signal to obtain an MTD result; according to the MTD result, determining a clutter type needing to be suppressed, and according to the clutter type needing to be suppressed, performing mean value type constant false alarm detection processing on the intermediate frequency echo signal to obtain a processing result of the intermediate frequency echo signal; wherein the mean value class constant false alarm detection processing is any one of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection. According to the method, the signal processing process is dynamically adjusted according to different environment conditions, the detection threshold can be changed along with the change of the clutter type, the optimal clutter filtering effect is achieved, and therefore the false alarm probability and the missing report probability of a radar system are reduced.

Description

Technical Field

[0001] The present invention relates to the field of signal processing, and more specifically, to a radar signal processing method, system, terminal, medium and program product. Background Art

[0002] In radar signal processing, it is necessary to complete target detection, positioning, tracking, etc. in complex clutter conditions, which requires filtering and screening out the clutter.

[0003] Pulse compression, moving target detection (MTD), constant false alarm rate detection (CFAR) and other algorithms are important processing steps in radar signal processing. However, the processing effects of conventional processing processes may vary greatly under different clutter conditions, resulting in large differences in clutter filtering results under different weather and lighting conditions, thereby increasing the probability of false alarms and missed reports of the radar system. Summary of the invention

[0004] The purpose of the present invention is to provide a radar signal processing method, system, terminal, medium and program product. The present invention dynamically adjusts the signal processing process according to different environmental conditions, can change the detection threshold as the clutter type changes, and achieves the optimal clutter filtering effect, thereby reducing the probability of false alarms and missed reports of the radar system.

[0005] A first aspect of the present invention provides a radar signal processing method, the method comprising:

[0006] Receive intermediate frequency echo signal;

[0007] When it is detected that the intermediate frequency echo signal contains a clutter signal, MTD processing is performed on the intermediate frequency echo signal to obtain an MTD result;

[0008] The type of clutter that needs to be suppressed is determined according to the MTD result, and the mean-type constant false alarm detection processing is performed on the intermediate frequency echo signal according to the type of clutter that needs to be suppressed to obtain the processing result of the intermediate frequency echo signal; wherein the mean-type constant false alarm detection processing is any one of the three types of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection.

[0009] In one implementation, MTD processing is performed on the intermediate frequency echo signal, specifically:

[0010] Processing the beat signal in the intermediate frequency echo signal to obtain range gate data; wherein the range gate data is composed of M range units, where M is a positive integer;

[0011] Input one frame of range gate data in each accumulation cycle, and complete the storage of N frames of range gate data according to the number of pre-configured accumulation cycles N, to obtain N frames of data; wherein the N frames of data are a two-dimensional array with a row length of M and a column width of N, where N is a positive integer;

[0012] The distance units of the same distance unit in N frames of data are taken out for coherent accumulation to obtain the MTD result of N frames of data.

[0013] In one implementation, the distance units of the same distance unit in N frames of data are taken out for coherent accumulation, specifically:

[0014] For each frame of N frames, the data of the same distance unit are taken out in turn for coherent accumulation to obtain N*M data, the maximum value of the N*M data is selected to obtain M data, and the M data is used as the MTD result of one frame of data.

[0015] In one implementation, the coherent integration is performed as a fast Fourier transform.

[0016] In one implementation, a mean-type constant false alarm detection process is performed on the intermediate frequency echo signal according to the type of clutter to be suppressed, and a processing result of the intermediate frequency echo signal is obtained, including:

[0017] When the MTD result indicates that meteorological clutter needs to be suppressed, the maximum selection constant false alarm detection processing is performed on the intermediate frequency echo signal;

[0018] When the MTD result indicates that electromagnetic interference clutter in the same frequency band needs to be suppressed, the unit average constant false alarm detection processing is performed on the intermediate frequency echo signal;

[0019] When the MTD result indicates that no clutter needs to be suppressed, minimum selection constant false alarm detection processing is performed on the intermediate frequency echo signal.

[0020] In one implementation, the processing process of the mean-value constant false alarm detection is specifically as follows:

[0021] According to the intermediate frequency echo signal, a detection unit, a plurality of left reference units and a plurality of right reference units are obtained;

[0022] Summing a plurality of left reference cells to obtain a first sum value, and summing a plurality of right reference cells to obtain a second sum value;

[0023] Calculate the first local clutter level values ​​corresponding to the plurality of left reference units according to the sliding direction of the detection unit on the plurality of left reference units and the first sum value; wherein the detection unit steps one left reference unit and one right reference unit each time it slides;

[0024] According to the sliding direction of the detection unit on the plurality of right reference units and the second sum value, second local clutter level values ​​corresponding to the plurality of right reference units are calculated.

[0025] In one implementation, first local clutter level values ​​corresponding to a plurality of left reference units are calculated, specifically:

[0026] Determine the first element and the second element corresponding to the left reference unit according to the sliding direction; wherein the first element refers to a reference unit that the detection unit slides out from the left reference unit, and the second element refers to a reference unit that the detection unit slides into from the left reference unit;

[0027] Subtract the first sum from the first element and add the second element to obtain a first local clutter level value;

[0028] Calculate the second local clutter level values ​​corresponding to multiple right reference units, specifically:

[0029] Determine the third element and the fourth element corresponding to the right reference unit according to the sliding direction; wherein the third element refers to a reference unit that the detection unit slides out from the right reference unit, and the fourth element refers to a reference unit that the detection unit slides into from the right reference unit;

[0030] Subtract the third element from the second sum and add the fourth element to obtain a second local clutter level value.

[0031] In one implementation, when the MTD result indicates that meteorological clutter needs to be suppressed, a maximum selection constant false alarm detection process is performed on the intermediate frequency echo signal, specifically: taking the maximum value of the first local clutter level value and the second local clutter level value, and multiplying the maximum value by a pre-configured coefficient factor, calculating a detection threshold, and comparing the detection threshold with the value of the unit to be detected. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal;

[0032] When the MTD result indicates that electromagnetic interference clutter in the same frequency band needs to be suppressed, the unit average constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: the average value of the first local clutter level value and the second local clutter level value is calculated, and the average value is multiplied by a pre-configured coefficient factor to calculate the detection threshold, and the value between the detection threshold and the value of the unit to be detected is compared. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal;

[0033] When the MTD result shows that no clutter needs to be suppressed, the minimum selection constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: the minimum value of the first local clutter level value and the second local clutter level value is taken, and the minimum value is multiplied by a pre-configured coefficient factor to calculate the detection threshold, and the detection threshold is compared with the value of the unit to be detected. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal.

[0034] A second aspect of the present invention provides a radar signal processing system, the system comprising:

[0035] A signal receiving module, used for receiving an intermediate frequency echo signal;

[0036] The first signal processing module is used to perform MTD processing on the intermediate frequency echo signal to obtain an MTD result when a clutter signal is detected in the intermediate frequency echo signal;

[0037] The second signal processing module is used to determine the type of clutter that needs to be suppressed according to the MTD result, and perform mean-type constant false alarm detection processing on the intermediate frequency echo signal according to the type of clutter that needs to be suppressed to obtain a processing result of the intermediate frequency echo signal; wherein the mean-type constant false alarm detection processing is any one of the three types of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection.

[0038] According to a third aspect of the present invention, a radar signal receiving terminal is provided, comprising a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of a radar signal processing method provided in the first aspect of the present invention are implemented.

[0039] According to a fourth aspect of the present invention, a readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of a radar signal processing method provided in the first aspect of the present invention are implemented.

[0040] According to a fifth aspect of the present invention, a computer program product is provided, comprising a computer program, wherein when the computer program is executed by a processor, the radar signal processing method provided in the first aspect of the present invention is implemented.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] In a radar signal processing method provided by an embodiment of the present invention, the parameter configuration for performing MTD processing is different in different clutter environments. The current conventional design is to generate MTD processing modules with multiple configurations. By reconfiguring or switching to select one of them, the moving target detection capability can be improved. However, the MTD processing modules in different environments have the defects of long switching time and high resource usage. In the MTD processing process provided by the present invention, by configuring the number of accumulation cycles and the number of distance units, a MTD resource utilization rate is repeatedly used to achieve the effect of saving time and saving processing resources. Secondly, in the clutter filtering process under different weather and illumination conditions, the current constant false alarm detection (CFAR) has better performance only under specific conditions. Once out of the applicable conditions, its performance will deteriorate rapidly, thereby seriously affecting the overall performance of radar signal processing. In addition, the current constant false alarm detection algorithm needs to calculate the mean of the reference units at the left and right ends of the detection unit and then multiply the coefficient factor to obtain the detection threshold, and the detection threshold is used to determine whether the object to be detected is a target or clutter. However, as the detection unit moves, the current constant false alarm detection algorithm needs to recalculate the mean of the reference units at the left and right ends, and repeatedly performs summing and averaging operations on the reference units at the left and right ends, which increases the calculation time. The constant false alarm detection algorithm provided by the present invention only calculates the sum of the reference units at the left and right sides once, and the rest is calculated according to the sliding direction of the detection unit. The sum calculated before only needs to be subtracted from the first element that slid out last time and then added to an element that slid in this time, thereby greatly reducing the calculation time generated by repeatedly addressing the reference units. It can be seen that the present invention dynamically adjusts the signal processing process according to different environmental conditions, and can change the detection threshold as the clutter changes, thereby achieving the optimal clutter filtering effect, thereby reducing the probability of false alarms and missed reports of the radar system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the drawings:

[0044] Figure 1 A schematic diagram of a flow chart of a radar signal processing method provided by an embodiment of the present invention;

[0045] Figure 2 A radar signal processing flow chart provided by an embodiment of the present invention;

[0046] Figure 3 A block diagram of an MTD implementation provided in an embodiment of the present invention;

[0047] Figure 4 A timing diagram of the MTD processing flow provided by an embodiment of the present invention;

[0048] Figure 5 A schematic diagram of the structure of N frames of data provided by an embodiment of the present invention;

[0049] Figure 6 Schematic diagram of mean CFAR provided for related technologies;

[0050] Figure 7 A schematic diagram of a mean-class CFAR provided by an embodiment of the present invention;

[0051] Figure 8 A principle block diagram of a radar signal processing system provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0052] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The exemplary embodiments of the present invention and their description are only used to explain the present invention and are not intended to limit the present invention.

[0053] It should be noted that the terms "include" or "may include" used in various embodiments of the present application indicate the presence of the function, operation or element applied for, and do not limit the addition of one or more functions, operations or elements. In addition, as used in various embodiments of the present application, the terms "include", "have" and their cognates are only intended to indicate specific features, numbers, steps, operations, elements, components or a combination of the foregoing items, and should not be understood as first excluding the presence of one or more other features, numbers, steps, operations, elements, components or a combination of the foregoing items or the possibility of adding one or more features, numbers, steps, operations, elements, components or a combination of the foregoing items.

[0054] In various embodiments of the present application, the expression "or" or "at least one of B or / and C" includes any combination or all combinations of the words listed at the same time. For example, the expression "B or C" or "at least one of B or / and C" may include B, may include C, or may include both B and C.

[0055] It should be understood that terms such as "first" and "second" are only used for descriptive purposes and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0056] In radar signal processing, it is necessary to complete target detection, positioning, tracking, etc. in complex clutter conditions, which requires filtering and screening out the clutter.

[0057] Pulse compression, moving target detection (MTD), constant false alarm rate detection (CFAR) and other algorithms are important processing steps in radar signal processing. However, the processing effects of conventional processing processes may vary greatly under different clutter conditions, resulting in large differences in clutter filtering results under different weather and lighting conditions, thereby increasing the probability of false alarms and missed reports of the radar system.

[0058] Therefore, in order to solve the above problems, an embodiment of the present invention provides a radar signal processing method. In this method, the parameter configuration for executing MTD processing is different under different clutter environments. The current conventional design is to generate MTD processing modules with multiple configurations. By reconfiguring or switching to select one of them, the moving target detection capability can be improved. However, the MTD processing modules in different environments have the defects of long switching time and high resource usage. In the MTD processing process provided by the present invention, by configuring the number of accumulation cycles and the number of distance units, a MTD resource utilization rate is repeatedly used to achieve the effect of saving time and saving processing resources. Secondly, in the clutter filtering process under different weather and illumination conditions, the current constant false alarm detection (CFAR) has better performance only under specific conditions. Once out of the applicable conditions, its performance will deteriorate rapidly, thereby seriously affecting the overall performance of radar signal processing. In addition, the current constant false alarm detection algorithm needs to calculate the mean of the reference units at the left and right ends of the detection unit and then multiply the coefficient factor to obtain the detection threshold, and the detection threshold is used to determine whether the object to be detected is a target or clutter. However, as the detection unit moves, the current constant false alarm detection algorithm needs to recalculate the mean of the reference units at the left and right ends, and repeatedly performs summing and averaging operations on the reference units at the left and right ends, which increases the calculation time. The constant false alarm detection algorithm provided by the present invention only calculates the sum of the reference units at the left and right sides once, and the rest is calculated according to the sliding direction of the detection unit. The sum calculated before only needs to be subtracted from the first element that slid out last time and then added to an element that slid in this time, thereby greatly reducing the calculation time generated by repeatedly addressing the reference units. It can be seen that the present invention dynamically adjusts the signal processing process according to different environmental conditions, and can change the detection threshold as the clutter changes, thereby achieving the optimal clutter filtering effect, thereby reducing the probability of false alarms and missed reports of the radar system.

[0059] Please refer to Figure 1 , Figure 1 A schematic diagram of a radar signal processing method provided by an embodiment of the present invention is shown in FIG. Figure 1 As shown, the method includes:

[0060] S101, receiving an intermediate frequency echo signal.

[0061] In this embodiment, as is common knowledge to those skilled in the art, an intermediate frequency echo signal reflected by a target can be received by the receiving antenna of the radar. The intermediate frequency echo signal is a signal received in the radar system. It is a process in which the transmitting signal is captured and converted to an intermediate frequency by the receiving antenna after being reflected by the target. Specifically, the intermediate frequency echo signal is an echo signal formed after the radar transmitting signal is reflected by the target. This echo signal contains information about the target, such as distance, speed, etc. The intermediate frequency echo signal is a signal formed after the transmitting signal is reflected by the flying target. Optionally, the number of flying targets is one, or the number of flying targets is at least two. The radar transmits the transmitting signal outward through the antenna, and the transmitting signal forms an echo signal after being reflected by the flying target, and the intermediate frequency echo signal is received through the antenna.

[0062] The received intermediate frequency echo signal is sequentially subjected to AD sampling, digital down-conversion and frequency discrimination processing until a linear frequency modulation signal is obtained.

[0063] S102: When it is detected that the intermediate frequency echo signal contains a clutter signal, MTD processing is performed on the intermediate frequency echo signal to obtain an MTD result.

[0064] In this embodiment, it is determined whether there is a clutter signal in the intermediate frequency echo signal. If there is, the moving target detection capability is improved by using the MTD method to improve the signal-to-noise ratio under a complex clutter background. Conventional filter group design in FPGA will use a large amount of DSP resources. In this embodiment, the FFT calculation method is used to complete the MTD design. The number of DSP resources used by the FFT design method is reduced by 80% compared with the filter group design method. In addition, the parameter configuration of MTD is different under different clutter environments. The conventional design is to generate MTD modules with multiple configurations, and select one of them through reconfiguration or switch selection. This method can solve the problem, but the MTD switching time is long and the resource usage is high in different clutter environments. Dynamic MTD can just solve this kind of problem. Dynamic MTD sends switching instructions through software. FPGA does not need to stop working. It can directly reconfigure the same MTD module dynamically and quickly, so that one MTD module can meet the time-sharing use of multiple configurations, which is fast and saves resources. The function of MTD is to optimize the algorithm of range gate data, improve the signal-to-noise ratio, and achieve the effect of strengthening the signal amplitude and reducing the noise floor amplitude. The input signal of MTD is the range gate data, and the output is the optimized range gate data. Figure 3 As shown, the dynamic MTD design provided in this embodiment mainly includes three parts: frame data storage, frame data address management, and coherent accumulation, among which frame data address management is the basis for completing dynamic operations. Specifically, the MTD processing process provided in this embodiment is as follows:

[0065] S1021, processing the beat signal in the intermediate frequency echo signal to obtain range gate data; wherein the range gate data is composed of M range units, where M is a positive integer.

[0066] In this embodiment, if Figure 4 As shown, after completing the beat signal preprocessing of the input intermediate frequency echo signal, the range gate data is obtained and input into the MTD module; the length M of the distance can be preconfigured.

[0067] S1022, input 1 frame of range gate data in each accumulation cycle, and complete the storage of N frames of range gate data according to the pre-configured number of accumulation cycles N, to obtain N frames of data; wherein the N frames of data are a two-dimensional array with a row length of M and a column width of N, where N is a positive integer.

[0068] In this embodiment, one frame of range gate data is input in each PRF cycle, and according to the number of accumulation cycles N configured by the software, N frames of range gate signals are stored; the stored N frames of data are a two-dimensional array with a row length of M and a column width of N, such as Figure 5 shown.

[0069] S1023, taking out the distance units of the same distance unit in N frames of data for coherent accumulation, and obtaining the MTD result of the N frames of data.

[0070] In this embodiment, each frame of data is composed of range gate data of length M. Therefore, the coherent accumulation process is: for each frame of data in N frames of data, the data of the same distance unit are taken out in turn for coherent accumulation to obtain N*M data, the maximum value of the N*M data is selected to obtain M data, and the M data is used as the MTD result of one frame of data.

[0071] Specifically, the coherent accumulation process can be completed by fast Fourier transform FFT, taking out N data in the first column and inputting them into FFT for calculation, and obtaining N data as a result, and selecting the maximum value of the N data (as the MTD result of distance 1);

[0072] Similarly, using the processing method of the first column of data provided in the above steps, the second column of data is taken out to calculate the MTD result of distance 2. After M cycles, M distance data are obtained, which constitute the MTD result of 1 frame of data and are output. It can be seen that the MTD algorithm provided in this embodiment can configure and change the number of accumulation cycles (N) and the number of distance units (M), so that a MTD resource utilization rate can be repeatedly used, saving a large amount of operating resources.

[0073] like Figure 4As shown, sliding window extraction is performed on the stored N frames of data, and the MTD processing of the next frame of data is completed in the same processing manner as the above steps. Since N frames of data are stored, N MTD results will eventually be obtained after all frame data are processed.

[0074] S103, determining the type of clutter that needs to be suppressed according to the MTD result, performing mean-type constant false alarm detection processing on the intermediate frequency echo signal according to the type of clutter that needs to be suppressed, and obtaining a processing result of the intermediate frequency echo signal; wherein the mean-type constant false alarm detection processing is any one of the three types of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection.

[0075] In the present embodiment, constant false alarm detection (CFAR) is a key link in radar signal processing, and also provides data source for subsequent target positioning and tracking. Its processing result directly affects the performance of the radar system. With the increasing complexity of the electromagnetic environment, radar needs to process more complex echo data, which puts higher requirements on constant false alarm detection. The existing constant false alarm detection method only has better performance under specific conditions. Once it is out of the applicable conditions, its performance will deteriorate rapidly, which will seriously affect the overall performance of radar signal processing.

[0076] like Figure 6 As shown in the figure, the mean-type CFAR provided by the current related technology mainly uses the mean of the echo data of the adjacent sliding window (also called the reference window) of the single-frame unit to be detected for processing, and calculates the detection threshold through the processed mean data. Select several reference units from the preprocessed data, calculate the local clutter level based on the data of the reference units on the left and right sides, and then multiply the coefficient factor to obtain the detection threshold, and compare the detection threshold with the unit to be detected; if the value of the unit to be detected is larger, the current point to be detected is considered to be the target, otherwise it is considered to be clutter and filtered out.

[0077] At present, constant false alarm detection is performed on the pre-processed data, and each echo data is a unit to be detected. Starting from the left, a constant false alarm calculation is performed on each unit to be detected to determine whether it is target data. Protection units and reference units need to be set on the left and right sides of each reference unit. When the target signal is large, it may occupy multiple distance units due to sampling, and the detection threshold value will increase. Therefore, protection units are set to prevent missed detection. The local clutter level is calculated through the reference unit to make target judgments. The number of protection units and reference units can be set through the host computer control to achieve the optimal clutter filtering effect.

[0078] like Figure 2 As shown, when the MTD result indicates that meteorological clutter needs to be suppressed, maximum selection constant false alarm detection (GO-CFAR) processing is performed on the intermediate frequency echo signal.

[0079] When the MTD result indicates that electromagnetic interference clutter in the same frequency band needs to be suppressed, a unit average constant false alarm detection (CA-CFAR) process is performed on the intermediate frequency echo signal.

[0080] When the MTD result indicates that no clutter needs to be suppressed, a minimum selection constant false alarm detection (SO-CFAR) process is performed on the intermediate frequency echo signal.

[0081] Specifically, meteorological clutter refers to meteorological clutter such as rain and snow, and electromagnetic interference clutter in the same frequency band refers to signals with the same frequency band as the intermediate frequency echo signal.

[0082] like Figure 7 As shown, in some embodiments, the processing process of the mean-type constant false alarm detection is specifically as follows: according to the intermediate frequency echo signal, a detection unit, multiple left reference units and multiple right reference units are obtained; the multiple left reference units are summed to obtain a first sum value, and the multiple right reference units are summed to obtain a second sum value; according to the sliding direction of the detection unit in the multiple left reference units and the first sum value, the first local clutter level values ​​corresponding to the multiple left reference units are calculated; wherein, the detection unit steps one left reference unit and one right reference unit each time it slides; according to the sliding direction of the detection unit in the multiple right reference units and the second sum value, the second local clutter level values ​​corresponding to the multiple right reference units are calculated.

[0083] In this embodiment, the comparison Figure 6 and Figure 7 It can be seen that the constant false alarm detection algorithm provided by the relevant technology calculates the mean value (A and B) of the reference units on the left and right ends of the detection unit, takes the average, maximum and minimum, and finally multiplies it by the coefficient factor to determine the detection threshold. The detection threshold is compared with the value of the protection unit in the comparator to determine whether it is the target object. As the detection unit moves, the reference units on the left and right sides (x N and N), the detection algorithm will repeatedly sum and average the data, which consumes computing time. The optimization method provided by this embodiment is: determine the first element and the second element corresponding to the left reference unit according to the sliding direction; wherein the first element refers to a reference unit that the detection unit slides out from the left reference unit, and the second element refers to a reference unit that the detection unit slides into from the left reference unit; subtract the first sum from the first element, and add the second element to obtain the first local clutter level value. And, calculate the second local clutter level values ​​corresponding to multiple right reference units, specifically: determine the third element and the fourth element corresponding to the right reference unit according to the sliding direction; wherein the third element refers to a reference unit that the detection unit slides out from the right reference unit, and the fourth element refers to a reference unit that the detection unit slides into from the right reference unit; subtract the second sum from the third element, and add the fourth element to obtain the second local clutter level value.

[0084] It should be noted that, taking the left reference unit as an example, the sliding direction can be from left to right or from right to left. For example, taking the left reference unit as an example, when the sliding direction is from left to right, then first calculate SUM1=x1+x2+......+x N , then calculate SUM1'=SUM1-x1+x N+1 , that is, the new summation value is calculated by the left-out and right-in method according to the right shift of the detection unit for the first summation value. It is only necessary to subtract the first element on the left of the previous summation value and then add the first element that appears most recently, thereby greatly reducing the time for addressing and calculating repeated data. In other words, it reduces the overall process time of the constant false alarm detection algorithm. Secondly, the number of reference units and protection units can be dynamically adjusted to achieve the most effective clutter suppression. For example, when it is necessary to suppress meteorological clutter such as rain and snow, the reference unit is set to 64 and the protection unit is 4. GO-CFAR suppresses meteorological clutter; when it is necessary to suppress electromagnetic interference signals in the same frequency band, the reference unit is set to 128 and the protection unit is 2. CA-CFAR suppresses electromagnetic interference signals in the same frequency band. Finally, this embodiment can also increase the number of reference units to make several consecutive points in the same direction clear, and can also make continuous targets in the same direction clear by adjusting the detection threshold value.

[0085] In some embodiments, when the MTD result indicates that meteorological clutter needs to be suppressed, a maximum selection constant false alarm detection process is performed on the intermediate frequency echo signal, specifically: taking the maximum value of the first local clutter level value and the second local clutter level value, and multiplying the maximum value by a pre-configured coefficient factor, calculating a detection threshold, and comparing the detection threshold with the value of the unit to be detected. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal;

[0086] When the MTD result indicates that electromagnetic interference clutter in the same frequency band needs to be suppressed, the unit average constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: the average value of the first local clutter level value and the second local clutter level value is calculated, and the average value is multiplied by a pre-configured coefficient factor to calculate the detection threshold, and the value between the detection threshold and the value of the unit to be detected is compared. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal;

[0087] When the MTD result shows that no clutter needs to be suppressed, the minimum selection constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: the minimum value of the first local clutter level value and the second local clutter level value is taken, and the minimum value is multiplied by a pre-configured coefficient factor to calculate the detection threshold, and the detection threshold is compared with the value of the unit to be detected. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal.

[0088] Specifically, the process of determining whether it is a target object or clutter provided in this embodiment is a conventional technical means of constant false alarm detection processing, and this embodiment will not be redundantly described.

[0089] Please refer to Figure 8 , Figure 8 A schematic block diagram of a radar signal processing system provided by an embodiment of the present invention is shown in FIG. Figure 8 As shown, the system includes:

[0090] A signal receiving module 810 is used to receive an intermediate frequency echo signal;

[0091] The first signal processing module 820 is used to perform MTD processing on the intermediate frequency echo signal to obtain an MTD result when a clutter signal is detected in the intermediate frequency echo signal;

[0092] The second signal processing module 830 is used to determine the type of clutter that needs to be suppressed according to the MTD result, and perform mean-type constant false alarm detection processing on the intermediate frequency echo signal according to the type of clutter that needs to be suppressed to obtain a processing result of the intermediate frequency echo signal; wherein the mean-type constant false alarm detection processing is any one of the three types of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection.

[0093] A radar signal processing system in an embodiment of the present application is Figure 1The radar signal processing method shown is a technical solution based on the same inventive concept. Through the detailed description of the radar signal processing method provided in the above embodiment, those skilled in the art can clearly understand the implementation process of a radar signal processing system in this embodiment, so for the sake of brevity of the specification, it will not be repeated here.

[0094] In a radar signal processing system provided by an embodiment of the present invention, the parameter configuration for performing MTD processing is different in different clutter environments. The current conventional design is to generate MTD processing modules with multiple configurations. By reconfiguring or switching to use one of them, the moving target detection capability can be improved. However, the MTD processing modules in different environments have the defects of long switching time and high resource usage. In the MTD processing process provided by the present invention, by configuring the number of accumulation cycles and the number of distance units, a MTD resource utilization rate is repeatedly used to achieve the effect of saving time and saving processing resources. Secondly, in the clutter filtering process under different weather and illumination conditions, the current constant false alarm detection (CFAR) has better performance only under specific conditions. Once out of the applicable conditions, its performance will deteriorate rapidly, thereby seriously affecting the overall performance of radar signal processing. In addition, the current constant false alarm detection algorithm needs to calculate the mean of the reference units at the left and right ends of the detection unit and then multiply the coefficient factor to obtain the detection threshold, and the detection threshold is used to determine whether the object to be detected is a target or clutter. However, as the detection unit moves, the current constant false alarm detection algorithm needs to recalculate the mean of the reference units at the left and right ends, and repeatedly performs summing and averaging operations on the reference units at the left and right ends, which increases the calculation time. The constant false alarm detection algorithm provided by the present invention only calculates the sum of the reference units at the left and right sides once, and the rest is calculated according to the sliding direction of the detection unit. The sum calculated before only needs to be subtracted from the first element that slid out last time and then added to an element that slid in this time, thereby greatly reducing the calculation time generated by repeatedly addressing the reference units. It can be seen that the present invention dynamically adjusts the signal processing process according to different environmental conditions, and can change the detection threshold as the clutter changes, thereby achieving the optimal clutter filtering effect, thereby reducing the probability of false alarms and missed reports of the radar system.

[0095] An embodiment of the present invention further provides a radar signal receiving terminal, which includes a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of a radar signal processing method described in the above embodiment are implemented.

[0096] The embodiment of the present invention also provides a radar signal receiving terminal. The terminal in the present application may include one or more of the following components: a processor and a memory. The processor uses various interfaces and lines to connect the various parts of the entire terminal, and executes various functions of the terminal and processes data by running or executing instructions, programs, code sets or instruction sets stored in the memory, and calling data stored in the memory. Optionally, the processor can be implemented in at least one hardware form of digital signal processing (DSP), field programmable gate array (FPGA), and programmable logic array (PLA). The processor can integrate one or more combinations of a central processing unit (CPU), a graphics processing unit (GPU), a neural network processor (NPU), and a modem. Among them, the CPU mainly processes the operating system, user interface, and application programs; the GPU is responsible for rendering and drawing the content to be displayed on the touch display; the NPU is used to implement artificial intelligence (AI) functions; and the modem is used to process wireless communications. It is understandable that the above-mentioned modem may not be integrated into the processor, but may be implemented by a separate chip.

[0097] The memory may include a random access memory (RAM) or a read-only memory (ROM). Optionally, the memory includes a non-transitory computer-readable storage medium. The memory may be used to store instructions, programs, codes, code sets or instruction sets. The memory may include a program storage area and a data storage area, wherein the program storage area may store instructions for implementing an operating system, instructions for at least one function (such as a touch function, a sound playback function, an image playback function, etc.), instructions for implementing the following various method embodiments, etc.; the data storage area may store data created according to the use of the terminal (such as audio data, a phone book), etc. The terminal in the embodiment of the present application also includes a communication component and a display component. Among them, the communication component may be a Bluetooth component, a WiFi (WIreless-Fidelity) component, an NFC (Near Field Communication, near field communication) component, etc., for communicating with an external device (server or other terminal device) via a wired or wireless network; the display component is used to display a graphical user interface, and / or receive user interaction operations. In addition, those skilled in the art will appreciate that the structure of the terminal shown in the above drawings does not constitute a limitation on the terminal, and the terminal may include more or fewer components than shown, or combine certain components, or arrange the components differently. For example, the terminal also includes a radio frequency circuit, an input unit, a sensor, an audio circuit, a speaker, a microphone, a power supply, and other components, which will not be described in detail here.

[0098] The embodiment of the present invention also provides a readable storage medium, which is a memory device in a computer device for storing programs and data. It is understandable that the readable storage medium here can include both built-in storage media in the computer device and extended storage media supported by the computer device. The readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the readable storage medium here can be a high-speed RAM memory or a non-volatile memory (non-volatile memory), such as at least one disk memory. The processor can load and execute one or more instructions stored in the readable storage medium to implement the corresponding steps of a radar signal processing method in the above embodiment. Those skilled in the art should understand that the embodiment of the present invention can be provided as a method, a system, or a computer program product. Therefore, the present invention can take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program codes.

[0099] The embodiment of the present invention further provides a computer program product, the computer program product or computer program includes computer instructions, the computer instructions are stored in a computer-readable storage medium. The processor of the computer device reads the computer instructions from the computer-readable storage medium, and the processor executes the computer instructions, so that the computer device executes the radar signal processing method provided in the above embodiment.

[0100] Those skilled in the art should be aware that in one or more of the above examples, the functions described in the embodiments of the present application can be implemented with hardware, software, firmware, or any combination thereof. When implemented using software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or codes on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein the communication media include any media that facilitates the transmission of a computer program from one place to another. The storage medium can be any available medium that a general or special-purpose computer can access.

[0101] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A radar signal processing method, characterized in that the method include: Receive intermediate frequency echo signal; When it is detected that the intermediate frequency echo signal contains a clutter signal, MTD processing is performed on the intermediate frequency echo signal to obtain an MTD result; The type of clutter that needs to be suppressed is determined according to the MTD result, and the mean-type constant false alarm detection processing is performed on the intermediate frequency echo signal according to the type of clutter that needs to be suppressed to obtain the processing result of the intermediate frequency echo signal; wherein the mean-type constant false alarm detection processing is any one of the three types of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection.

2. A radar signal processing method according to claim 1, characterized in that: Perform MTD processing on the intermediate frequency echo signal, specifically: Processing the beat signal in the intermediate frequency echo signal to obtain range gate data; wherein the range gate data is composed of M range units, where M is a positive integer; Input one frame of range gate data in each accumulation cycle, and complete the storage of N frames of range gate data according to the number of pre-configured accumulation cycles N, to obtain N frames of data; wherein the N frames of data are a two-dimensional array with a row length of M and a column width of N, where N is a positive integer; The distance units of the same distance unit in N frames of data are taken out for coherent accumulation to obtain the MTD result of N frames of data.

3. A radar signal processing method according to claim 2, characterized in that: Take out the distance units of the same distance unit in N frames of data for coherent accumulation, specifically: For each frame of N frames, the data of the same distance unit are taken out in turn for coherent accumulation to obtain N*M data, the maximum value of the N*M data is selected to obtain M data, and the M data is used as the MTD result of one frame of data.

4. A radar signal processing method according to claim 3, characterized in that: The coherent integration is performed as a Fast Fourier Transform.

5. The radar signal processing method according to claim 1, characterized in that: Perform mean-value constant false alarm detection processing on the intermediate frequency echo signal according to the type of clutter to be suppressed, and obtain the processing result of the intermediate frequency echo signal, including: When the MTD result indicates that meteorological clutter needs to be suppressed, the maximum selection constant false alarm detection processing is performed on the intermediate frequency echo signal; When the MTD result indicates that electromagnetic interference clutter in the same frequency band needs to be suppressed, the unit average constant false alarm detection processing is performed on the intermediate frequency echo signal; When the MTD result indicates that no clutter needs to be suppressed, minimum selection constant false alarm detection processing is performed on the intermediate frequency echo signal.

6. A radar signal processing method according to claim 5, characterized in that: The processing process of the mean-value constant false alarm detection is specifically as follows: According to the intermediate frequency echo signal, a detection unit, a plurality of left reference units and a plurality of right reference units are obtained; Summing a plurality of left reference cells to obtain a first sum value, and summing a plurality of right reference cells to obtain a second sum value; Calculate the first local clutter level values ​​corresponding to the plurality of left reference units according to the sliding direction of the detection unit on the plurality of left reference units and the first sum value; wherein the detection unit steps one left reference unit and one right reference unit each time it slides; According to the sliding direction of the detection unit on the plurality of right reference units and the second sum value, second local clutter level values ​​corresponding to the plurality of right reference units are calculated.

7. A radar signal processing method according to claim 6, characterized in that: Calculate the first local clutter level values ​​corresponding to multiple left reference units, specifically: Determine the first element and the second element corresponding to the left reference unit according to the sliding direction; wherein the first element refers to a reference unit that the detection unit slides out from the left reference unit, and the second element refers to a reference unit that the detection unit slides into from the left reference unit; Subtract the first sum from the first element and add the second element to obtain a first local clutter level value; Calculate the second local clutter level values ​​corresponding to multiple right reference units, specifically: Determine the third element and the fourth element corresponding to the right reference unit according to the sliding direction; wherein the third element refers to a reference unit that the detection unit slides out from the right reference unit, and the fourth element refers to a reference unit that the detection unit slides into from the right reference unit; Subtract the third element from the second sum and add the fourth element to obtain a second local clutter level value.

8. A radar signal processing method according to claim 7, characterized in that: When the MTD result indicates that meteorological clutter needs to be suppressed, the maximum selection constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: taking the maximum value of the first local clutter level value and the second local clutter level value, and multiplying the maximum value by a pre-configured coefficient factor, calculating the detection threshold, and comparing the detection threshold with the value of the unit to be detected. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal; When the MTD result indicates that electromagnetic interference clutter in the same frequency band needs to be suppressed, the unit average constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: the average value of the first local clutter level value and the second local clutter level value is calculated, and the average value is multiplied by a pre-configured coefficient factor to calculate the detection threshold, and the value between the detection threshold and the value of the unit to be detected is compared. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal; When the MTD result shows that no clutter needs to be suppressed, the minimum selection constant false alarm detection processing is performed on the intermediate frequency echo signal, specifically: the minimum value of the first local clutter level value and the second local clutter level value is taken, and the minimum value is multiplied by a pre-configured coefficient factor to calculate the detection threshold, and the detection threshold is compared with the value of the unit to be detected. If the detection threshold is greater than the value of the unit to be detected, the unit to be detected is filtered out, otherwise, the unit to be detected is the processing result of the intermediate frequency echo signal.

9. A radar signal processing system, characterized in that: The system includes: A signal receiving module, used for receiving an intermediate frequency echo signal; The first signal processing module is used to perform MTD processing on the intermediate frequency echo signal to obtain an MTD result when a clutter signal is detected in the intermediate frequency echo signal; The second signal processing module is used to determine the type of clutter that needs to be suppressed according to the MTD result, and perform mean-type constant false alarm detection processing on the intermediate frequency echo signal according to the type of clutter that needs to be suppressed to obtain a processing result of the intermediate frequency echo signal; wherein the mean-type constant false alarm detection processing is any one of the three types of unit average constant false alarm detection, maximum selection constant false alarm detection and minimum selection constant false alarm detection.

10. A radar signal receiving terminal, characterized in that: The radar signal receiving terminal includes a processor, a memory, and a computer program stored in the memory and executable by the processor, wherein when the computer program is executed by the processor, the steps of a radar signal processing method according to any one of claims 1 to 8 are implemented.

11. A readable storage medium, characterized in that: The readable storage medium stores a computer program, wherein when the computer program is executed by a processor, the steps of a radar signal processing method according to any one of claims 1 to 8 are implemented.

12. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, a radar signal processing method according to any one of claims 1 to 8 is implemented.

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