An airborne fire control radar scanning system identification method and system

Abstract

The application relates to the technical field of radar scanning system identification, and discloses an airborne fire control radar scanning system identification method and system. The method adopts a quadratic polynomial to fit a search envelope of a target radar, calculates a fitting error by using a model obtained through fitting, and finally compares the fitting error with a set threshold value to determine the scanning system type. The application solves the following problems existing in the prior art: under a complex environment, signal measurement error is increased or there are more pulse losses.

Description

Technical Field

[0001] This invention relates to the field of radar scanning mode identification technology, specifically a method and system for identifying airborne fire control radar scanning modes. Background Technology

[0002] Airborne fire control radar plays a crucial role in locking onto and engaging targets in air combat. Currently, there are two main types of airborne fire control radar: mechanical scanning and phased array. Phased array radar poses a significantly higher threat level than mechanical scanning radar. Furthermore, fighter jets equipped with mechanical scanning radar, both domestically and internationally, are all third-generation or earlier models, whose performance and weapon systems are significantly weaker than fourth- and fifth-generation fighter jets equipped with phased array radar. Therefore, identifying the scanning mode of a target's airborne fire control radar is extremely important for understanding the target and selecting appropriate tactics and strategies.

[0003] The main difference between mechanically scanned radar and phased array radar signals presented by the interceptor lies in the variation of pulse amplitude over time. The paper "A Phased Array Radar Recognition Method Based on Wavelet Packet Transform" performs a Fast Fourier Transform on the scanning envelope of the detected signal to extract spectral sideband wavelet packet features and uses SVM for classification. However, it struggles to handle complex scenarios with increased signal measurement errors or significant pulse loss, and its generalization performance is generally poor. The paper "Phased Array Radar Recognition Technology Based on Signal Clustering Degree" distinguishes scanning systems by calculating a defined signal clustering degree. However, the signal clustering degree varies significantly across different radars, and fluctuates greatly when there are many pulse losses, making it difficult to determine the judgment threshold. The paper "A Radar Scanning System Recognition Method Based on SVM and DNN" proposes using statistical histograms as features and training with SVM and deep learning methods. The SVM-based method performs poorly when signal measurement errors increase or there are many pulse losses, while the deep learning-based method requires a high degree of data diversity.

[0004] The patent "A Method for Identifying Phased Array Radar Systems" (patent application number 201911097552.8) obtains a theoretical model of pulse amplitude through a receiver model and a theoretical radiation pattern of the radar antenna. It then cross-correlates the theoretical model with actual received data and uses the similarity coefficient to determine the scanning system. However, this method requires some parameter assumptions about the target radar, and the similarity coefficient fluctuates significantly when signal measurement errors increase or when there are many pulse losses. The patent "A Method for Identifying Electronically Scanned Radar Signals Using Intercepted Signal Amplitude Values" (patent application number 202210183193.3) first extracts the maximum main lobe of the received signal, performs autocorrelation on the maximum main lobe signal, determines the first minimum point on the left and right of the autocorrelation function value with zero shift in the autocorrelation function value sequence, and calculates the first and second time lengths to determine the first and second main beam signals. It then selects the maximum main beam signal and calculates its flatness for scanning system discrimination. This algorithm is complex, involves many judgments, is sensitive to signal values, and is difficult to adapt to situations where signal measurement errors increase or there are many pulse losses. Summary of the Invention

[0005] To overcome the shortcomings of existing technologies, this invention provides an airborne fire control radar scanning system identification method and system, which solves the following problems in existing technologies: increased signal measurement errors or significant pulse loss in complex environments.

[0006] The technical solution adopted by the present invention to solve the above problems is:

[0007] A method for identifying the scanning regime of an airborne fire control radar is proposed. The method uses a quadratic polynomial to fit the search envelope of the target radar, then uses the fitted model to calculate the fitting error, and finally compares the fitting error with a set threshold to determine the scanning regime type.

[0008] As a preferred technical solution, the steps include:

[0009] S1, Quadratic polynomial fitting: Obtain a search envelope of a single radar target after sorting, and extract data in two dimensions: pulse arrival time and pulse amplitude. Use pulse arrival time as the independent variable and pulse amplitude as the dependent variable to perform quadratic polynomial fitting.

[0010] S2, Calculation of envelope average fitting error: Using the pulse arrival time as the independent variable, the fitting pulse amplitude is calculated using the quadratic polynomial obtained by fitting, and then the fitting error is obtained by comparing the fitting pulse amplitude with the actual pulse amplitude.

[0011] S3, Error Judgment: Set the corresponding threshold according to the fitting error calculation method, compare the fitting error with the threshold, and obtain the target scanning system type.

[0012] As a preferred technical solution, step S1 includes the following steps:

[0013] S11, Obtain a search envelope S for a single radar target after sorting, and extract the pulse arrival time TOA from the envelope S. S =[t1,t2,...,t i ,...,t n Extract the pulse amplitude PA from the envelope S. S =[A1,A2,...,A i ,...,A n ]; where i represents the pulse number in the envelope S, n represents the number of pulses in the envelope S, and t i A represents the arrival time of the i-th pulse. i This represents the pulse amplitude of the i-th pulse;

[0014] S12, for the quadratic polynomial f(t) = w0 + w1t + w2t 2 Using TOA in step S11 S The value of input t is determined by PA in step S11. S The values ​​of f(t) are used to perform polynomial fitting to obtain the fitted model f; where t represents the independent variable, w0 represents the constant term, w1 represents the coefficient of the first term, and w2 represents the coefficient of the second term.

[0015] As a preferred technical solution, in step S12, the fitting method includes, but is not limited to: minimizing the sum of absolute values ​​of deviations, minimizing the maximum absolute value of deviations, and minimizing the sum of squared deviations.

[0016] As a preferred technical solution, step S2 includes the following steps:

[0017] S21, using the fitting model f from step S12, the pulse arrival time TOA extracted in step S11 is... S =[t1,t2,...,t i ,...,t n The value of t is used as the input value to calculate the fitted pulse amplitude PA. f =[A'1,A'2,...,A' i ,...A' n ]; where A' i This represents the fitted pulse amplitude of the i-th pulse;

[0018] S22, the fitted pulse amplitude PA obtained through the total calculation in step S21. f =[A'1,A'2,...,A' i ,...A' n The pulse amplitude PA extracted in step S11S =[A1,A2,...,A i ,...,A n ] Calculate the fitting error E ave .

[0019] As a preferred technical solution, in step S22, the methods for calculating the fitting error include, but are not limited to: root mean square error, mean absolute error, and mean relative error.

[0020] As a preferred technical solution, step S3 includes the following steps:

[0021] S31, Determine the judgment threshold E. If the average fitting error E ave If the value is less than or equal to E, proceed to step S32; otherwise, proceed to step S33.

[0022] S32, determine that the radar target scanning mode type corresponding to the current scanning envelope is mechanical scanning;

[0023] S33, determine that the radar target scanning system type corresponding to the current scanning envelope is phased array.

[0024] As a preferred technical solution, in step S31, the method for determining the judgment threshold includes, but is not limited to: root mean square error, mean absolute error, and mean relative error.

[0025] An airborne fire control radar scanning pattern identification system, used to implement the aforementioned airborne fire control radar scanning pattern identification method, includes the following modules connected in sequence:

[0026] The quadratic polynomial fitting module is used to obtain a search envelope of a single radar target after sorting, and extract data in two dimensions: pulse arrival time and pulse amplitude. The pulse arrival time is used as the independent variable and the pulse amplitude is used as the dependent variable to perform quadratic polynomial fitting.

[0027] Envelope average fitting error calculation module: It is used to calculate the fitted pulse amplitude using the pulse arrival time as the independent variable and the quadratic polynomial obtained by fitting, and then obtain the fitting error by comparing the fitted pulse amplitude with the actual pulse amplitude.

[0028] Error determination module: Used to set the corresponding threshold according to the fitting error calculation method, compare the fitting error with the threshold, and obtain the target scanning system type.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] This invention only requires fitting the current envelope and calculating the fitting error. The algorithm is simple, and the fitting model is a quadratic polynomial model that has good distinguishability between the inherent characteristics of mechanically scanned radar and phased array radar. At the same time, only one threshold needs to be set, which can adapt to situations where signal measurement errors increase or there are many pulse losses in complex environments. Attached Figure Description

[0031] Figure 1 This is a flowchart of an airborne fire control radar scanning system identification method according to the present invention;

[0032] Figure 2 This is a schematic diagram comparing the fitting errors of mechanical scanning and phased array airborne fire control radars. Detailed Implementation

[0033] The present invention will be further described in detail below with reference to the embodiments and accompanying drawings, but the embodiments of the present invention are not limited thereto.

[0034] Example 1

[0035] like Figures 1 to 2 As shown, the purpose of this invention is to solve the problem of adaptability in complex environments where signal measurement errors increase or there are many lost pulses, and to propose an airborne fire control radar scanning system identification method.

[0036] To achieve the above objectives, the present invention adopts the following technical solution: an airborne fire control radar scanning system identification method, which first obtains a search envelope of the target radar, fits the search envelope using a quadratic polynomial, calculates the fitting error using the fitted model, and finally determines the scanning system type by comparing the fitting error with a set threshold.

[0037] Furthermore, the specific implementation method is as follows:

[0038] Step 1: Perform quadratic polynomial fitting on the envelope: Obtain a search envelope for a single radar target after sorting, and extract data from two dimensions: pulse arrival time and pulse amplitude. Use pulse arrival time as the independent variable and pulse amplitude as the dependent variable to perform quadratic polynomial fitting.

[0039] Step 2: Calculate the envelope average fitting error: Using the pulse arrival time as the independent variable, calculate the fitted pulse amplitude using the quadratic polynomial obtained from the fitting, and then obtain the fitting error by comparing the fitted pulse amplitude with the actual pulse amplitude.

[0040] Step 3, Error Determination: Set the corresponding threshold according to the fitting error calculation method, compare the fitting error with the threshold, and obtain the target scanning system type.

[0041] Furthermore, the specific method for step 1 is as follows:

[0042] Step 1.1: Obtain a search envelope S for a single sorted radar target, and extract the pulse arrival time (TOA) from the envelope S. S =[t1,t2,...,t n Extract the pulse amplitude PA from the envelope S. S =[A1,A2,...,A n ], where n is the number of pulses in the envelope S.

[0043] Step 1.2: For the quadratic polynomial f(t) = w0 + w1t + w2t 2 Using the TOA in step 1.1 S The value of input t is determined using PA from step 1.1. S As the value of f(t), a polynomial fitting is performed to obtain the fitted model f. The fitting method can be, but is not limited to, minimizing the sum of the absolute values ​​of the deviations, minimizing the maximum absolute value of the deviations, minimizing the sum of the squares of the deviations, etc.

[0044] Furthermore, the specific method for step 2 is as follows:

[0045] Step 2.1: Using the fitting model f from Step 1.2, the pulse arrival time TOA extracted in Step 1.1 is... S =[t1,t2,...,t n The value of t is used as the input value to calculate the fitted pulse amplitude PA. f =[A'1,A'2,...,A' n ].

[0046] Step 2.2: The fitted pulse amplitude PA obtained from the total calculation in Step 2.1 f =[A'1,A'2,...,A' n The pulse amplitude PA extracted in step 1.1 S =[A1,A2,...,A n ] Calculate the fitting error E ave Error calculation can be performed using, but is not limited to, root mean square error, mean absolute error, and mean relative error.

[0047] Furthermore, the specific method for step 3 is as follows:

[0048] Step 3.1: Determine the judgment threshold E according to the error calculation method used in Step 2.2. If the average fitting error E ave If the result is ≤E, proceed to step 3.2; otherwise, proceed to step 3.3.

[0049] Step 3.2: Determine that the radar target scanning mode type corresponding to the current scanning envelope is mechanical scanning.

[0050] Step 3.3: Determine that the radar target scanning system type corresponding to the current scanning envelope is phased array.

[0051] This invention provides a method for identifying the scanning system of an airborne fire control radar. The method only requires fitting the current envelope and calculating the fitting error. The algorithm is simple, and the fitting model is a quadratic polynomial model that has good distinguishability between the inherent characteristics of mechanically scanned radar and phased array radar. At the same time, only one threshold needs to be set, which can adapt to situations where signal measurement errors increase or there are many pulse losses in complex environments.

[0052] Example 2

[0053] like Figures 1 to 2 As shown, as a further optimization of Embodiment 1, this embodiment also includes the following technical features based on Embodiment 1:

[0054] The implementation process of an airborne fire control radar scanning system identification method is as follows: Figure 1 As shown. This implementation example addresses the challenges of measurement errors and pulse loss in complex environments. It selects the search envelopes of 30 mechanically scanned radars and 30 phased array radars for scanning system identification. The following explanation uses the search envelope S0 of one of the mechanically scanned radars as an example. The specific implementation steps are as follows:

[0055] Step 1.1: Obtain the scanning envelope S0 and extract the pulse arrival time TOA from the envelope S0. S =[250050620.05,250058020.255,...,250160432.11], extract the pulse amplitude PA from the envelope S. S = [41.75, 46.5, ..., 41.5], number of pulses n = 46.

[0056] Step 1.2: For the quadratic polynomial f(t) = w0 + w1t + w2t 2 Using the TOA in step 1.1 S The value of input t is determined using PA from step 1.1. S Using the values ​​of f(t), a polynomial fitting is performed to obtain the fitted model f, employing the method that minimizes the sum of squared deviations. The fitted model is f(t) = -306635542.15 + 2.45t + -4.9e -9 t 2 .

[0057] Step 2.1: Use the fitting model from Step 1.2: f(t) = -306635542.15 + 2.45t + -4.9e -9 t2 The pulse arrival time (TOA) extracted in step 1.1 is used. S =[250050620.05,250058020.255,...,250160432.11] is used as the input value t to calculate the fitted pulse amplitude PA. f =[42.57,46.30,...,42.76].

[0058] Step 2.2: The fitted pulse amplitude PA calculated in Step 2.1 is used. f =[42.57,46.30,...,42.76] and the pulse amplitude PA extracted in step 1.1 S =[41.75,46.5,...,41.5], calculate the fitting error using the root mean square error, and obtain the fitting error E. ave =0.95.

[0059] Step 3.1: Since the root mean square error calculation method is used, the judgment threshold E = 6 is set, and the average fitting error E ave =0.95≤6=E, proceed to step 3.2.

[0060] Step 3.2: Determine that the radar target scanning mode type corresponding to the current scanning envelope is mechanical scanning.

[0061] The method constructed in this invention uses steps 1 and 2 to calculate the average fitting error of the search envelopes of 30 mechanically scanned radars and 30 phased array radars, as shown in the figure. Figure 2 As shown, it can be seen that a threshold of E=6 can accurately distinguish the search envelope of mechanically scanned radar and the search envelope of phased array radar.

[0062] As described above, the present invention can be implemented well.

[0063] All features disclosed in all embodiments of this specification, or steps in all methods or processes implied in the disclosure, may be combined and / or extended or replaced in any way, except for mutually exclusive features and / or steps.

[0064] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Based on the technical essence of the present invention, any simple modifications, equivalent substitutions, and improvements made to the above embodiments within the spirit and principles of the present invention shall still fall within the protection scope of the present invention.

Claims

1. An airborne fire control radar scan mode identification method, characterized in that, The quadratic polynomial is used to fit the search envelope of the target radar, the fitting error is calculated by using the fitted model, and the scanning system type is determined by comparing the fitting error with the set threshold value; comprising the following steps: S1, quadratic polynomial fitting: obtaining a search envelope of a single radar target after sorting, and extracting data of two dimensions of pulse arrival time and pulse amplitude, taking the pulse arrival time as the independent variable and the pulse amplitude as the dependent variable, and performing quadratic polynomial fitting; S2, envelope average fitting error calculation: taking the pulse arrival time as the independent variable, calculating the fitted pulse amplitude by using the fitted quadratic polynomial, and then calculating the fitting error by comparing the fitted pulse amplitude with the real pulse amplitude; S3, error determination: setting a corresponding threshold value according to the fitting error calculation method, comparing the fitting error with the threshold value, and obtaining the target scanning system type.

2. The method of claim 1, wherein the method further comprises: Step S1 includes the following steps: S11, Obtain a search envelope of a single radar target after sorting. Extracting the envelope Pulse arrival time in Extracting the envelope Pulse amplitude ;in, Indicates envelope The pulse number in Indicates envelope The number of pulses in Indicates the first The arrival time of each pulse, Indicates the first The amplitude of each pulse; S12, a quadratic polynomial is fitted using the values of in step S11 as input and the values of in step S11 as values of to obtain a fitted model ; wherein denotes the independent variable, denotes the constant term, denotes the coefficient of the linear term, and denotes the coefficient of the quadratic term.

3. The method of claim 2, wherein the method further comprises: In step S12, the fitting method includes but is not limited to: minimizing the sum of absolute values of deviations, maximizing the minimum of absolute values of deviations, and minimizing the sum of squares of deviations.

4. The method of claim 3, wherein the method further comprises: Step S2 includes the following steps: S21, adopt the fitting model from step S12. The pulse arrival time extracted in step S11 As input The value of is used to calculate the fitted pulse amplitude. ;in, Indicates the first Fitted pulse amplitude for each pulse; S22, the fitting pulse amplitude calculated by step S21 with the pulse amplitude extracted in step Sll , the fitting error is calculated .

5. The method of claim 4, wherein, In step S22, the fitting error calculation method includes but is not limited to: root mean square error, mean absolute error, and mean relative error.

6. The method according to any one of claims 1 to 5, characterized in that, Step S3 includes the following steps: S31, determine a decision threshold if the average fitting error go to step S32, otherwise go to step S33; S32, determining that the scanning system type of the radar target corresponding to the current scanning envelope is mechanical scanning; S33, determining that the scanning system type of the radar target corresponding to the current scanning envelope is phased array.

7. The method of claim 6, wherein the method further comprises: In step S31, the determination threshold value method includes but is not limited to: root mean square error, mean absolute error, and mean relative error.

8. An airborne fire control radar scan mode identification system characterized by, An airborne fire control radar scanning system identification method according to any one of claims 1 to 7, comprising the following modules connected in sequence: A quadratic polynomial fitting module: used to obtain a search envelope of a single radar target after sorting, and extract data of two dimensions of pulse arrival time and pulse amplitude, taking the pulse arrival time as the independent variable and the pulse amplitude as the dependent variable, and performing quadratic polynomial fitting; An envelope average fitting error calculation module: used to take the pulse arrival time as the independent variable, calculate the fitted pulse amplitude by using the fitted quadratic polynomial, and then calculate the fitting error by comparing the fitted pulse amplitude with the real pulse amplitude; An error determination module: used to set a corresponding threshold value according to the fitting error calculation method, compare the fitting error with the threshold value, and obtain the target scanning system type.

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