A method and system for angle measurement of phased array radar in sinusoidal space

Abstract

The present application relates to radar target detection and tracking technical field, especially in a kind of phased array radar angle measurement method and system in sinusoidal space.The method includes: receiving multichannel echo signal and carrying out digitization and preprocessing, form baseband echo data;Pulse compression and coherent accumulation are carried out to baseband data, and distance-Doppler diagram is generated;The distance and speed information of target are obtained by target detection;The multichannel complex data corresponding to the distance gate and Doppler channel of target is extracted, the complex ratio of difference channel and sum channel is calculated, and the sinusoidal offset is obtained by combining pre-stored angle discrimination curve slope, and then the target angle is solved.The present application converts angle measurement process to sinusoidal space, realizes angle discrimination relationship linearization, only needs to store slope according to frequency point to complete high-precision angle measurement, simplifies processing procedure, and is suitable for multi-frequency point wide-angle scanning scene.

Description

Technical Field

[0001] This invention relates to the field of radar target detection and tracking technology, and in particular to a phased array radar angle measurement method and system in sinusoidal space. Background Technology

[0002] High-precision and high-efficiency measurement of target angles is a core component of radar target detection and tracking. Phased array radars, due to their beam agility and flexible signal processing capabilities, occupy an important position in modern radar systems. Monopulse angle measurement technology, as one of the main techniques for achieving high-precision angle measurement, is widely used because it can complete angle measurement within a single pulse.

[0003] Traditional single-pulse angle measurement methods (such as amplitude sum-difference and phase sum-difference methods) are significantly affected by the radar operating frequency and beam scanning angle in radar measurement coordinate systems (such as antenna coordinate systems). When the antenna beam scanning or operating frequency changes, the beam shape will be distorted and broadened, resulting in complex nonlinear changes in the azimuth and elevation angle discrimination curves. To ensure angle measurement accuracy, an independent set of angle discrimination curves needs to be calculated and stored for each frequency and each scanning position of the phased array radar. When there are many radar operating frequencies and scanning positions, the complexity and time of angle measurement calculations will increase significantly, and the system efficiency will decrease accordingly.

[0004] To address the aforementioned issues, existing technologies propose an angle measurement method for phased array radar based on sinusoidal space. Through coordinate system transformation and variable substitution, the nonlinear angle-sensitive function, which originally varies with frequency and scan angle in the radar measurement coordinate system, is transformed into a function with translational characteristics in sinusoidal space. This ensures that the angle-sensitive curve undergoes only a linear translation with beam scanning, thus allowing a set of angle-sensitive function curves measured in the normal direction to be applicable to different scan positions. This method reduces the complexity of testing and correcting the angle-sensitive function table to a certain extent.

[0005] However, the existing technology mainly focuses on the construction, fitting, and lookup correction of angle-sensitive functions in sinusoidal space, primarily revolving around the analysis of the radiation patterns of sum beams, azimuth difference beams, and elevation difference beams, the generation of angle-sensitive functions, and angle measurement based on lookup tables using sum-difference beam ratios and phase information. No complete processing solution has been provided for the subsequent signal processing after receiving the echo signal, especially how to combine pulse compression, coherent accumulation, range-Doppler processing, and target detection to improve the quality of the angle measurement input data.

[0006] Specifically, existing technologies still have shortcomings in the following aspects: Firstly, in existing technologies, there is a lack of a unified pulse compression and coherent accumulation processing flow for baseband echo data of the sum, azimuth, and pitch channels, making it difficult to generate corresponding range-Doppler maps. Secondly, existing technologies lack a processing flow for target detection based on channel distance-Doppler images and for obtaining the target's distance cell index and Doppler cell index. Third, in the existing technology, there is no technical solution to extract the corresponding target cell complex data from the sum channel, azimuth difference channel and pitch difference channel based on the detected range cell index and Doppler cell index, and to use the target cell complex data for ratio angle measurement.

[0007] In practical applications, especially under low signal-to-noise ratio echo conditions or multi-target detection scenarios, the data used in angle measurement calculations lacks good target pointing and anti-interference capabilities, thus affecting the stability and engineering applicability of the angle measurement results. Therefore, how to base angle measurement calculations on the complex data of the detected target units while retaining the advantages of sinusoidal space angle measurement has become an urgent technical problem to be solved. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a phased array radar angle measurement method and system in sinusoidal space.

[0009] To solve the above-mentioned technical problems, the present invention provides a phased array radar angle measurement method in sinusoidal space, comprising: Step S101: The phased array antenna receives the echo signal and acquires multi-channel analog echo signals; Step S102: Digitize and preprocess the multi-channel analog echo signal to form multi-channel baseband echo data; the multi-channel includes: a sum channel, an azimuth difference channel, and an elevation difference channel; Step S103: Perform pulse compression and coherent accumulation processing on the multi-channel baseband echo data respectively to generate a range-Doppler map; Step S104: Perform target detection on the range-Doppler image and obtain the range gate index and Doppler channel index of the target. Calculate the target's range and velocity based on the phased array radar system parameters. Step S105: For the detected target, extract the complex data of the multi-channel range gate and Doppler channel index, calculate the complex ratio of the azimuth difference channel to the sum channel, and the complex ratio of the pitch difference channel to the sum channel, calculate the sinusoidal offset based on the slope of the corresponding angle discrimination curve, and calculate the target angle.

[0010] According to the phased array radar angle measurement method of the present invention, step S102 specifically includes: The echo signals of the sum, azimuth, and pitch difference channels are sampled and quantized by an analog-to-digital converter to obtain the digital signals of the corresponding channels. Then, digital down-conversion processing is performed to obtain the baseband echo data of each channel.

[0011] According to the phased array radar angle measurement method of the present invention, step S103 specifically includes: Matched filtering is performed on the echo data of each channel to achieve range pulse compression; Fourier transform is performed along the pulse dimension on the pulse-compressed data of each channel to achieve coherent accumulation and obtain the range-Doppler map.

[0012] According to the phased array radar angle measurement method of the present invention, step S104 specifically includes: A preset algorithm is used to perform target detection with the range-Doppler map. The power of each point in the range-Doppler map is compared with a threshold. Points that exceed the threshold are identified as targets. The corresponding range gate index and Doppler channel index are recorded. The range and velocity information of the target are calculated based on the phased array radar system parameters.

[0013] According to the phased array radar angle measurement method of the present invention, the preset algorithm is a constant false alarm rate (CFAR) detection algorithm.

[0014] According to the phased array radar angle measurement method of the present invention, step S105 specifically includes: Based on the target's range gate index and Doppler channel index, extract the target's corresponding complex values ​​from the range-Doppler maps of the sum channel, azimuth channel, and pitch difference channel, respectively. , and ; Calculate the target azimuth difference, pitch difference, and the complex ratio of the channel. and And take the imaginary part; Based on the slope of the angle curve and The sinusoidal offset of the target relative to the beam center direction is calculated. and The true sinusoidal quantity of the target and It can be obtained from the following formula: ; Calculate the target angle, and the formula for calculating the target angle is: ; .

[0015] According to the phased array radar angle measurement method of the present invention, the calculation of target azimuth difference, elevation difference, and complex ratio of the channel is described. and The calculation formula is: ; ; in, Let X be the number of array elements in the X direction. Let Y be the number of array elements in the Y direction. For imaginary units, For wavelength, The spacing between array elements is in the X direction. The spacing between array elements in the Y direction. and yes The offset of the direction relative to the beam center in sinusoidal space.

[0016] According to the phased array radar angle measurement method of the present invention, the sinusoidal offset of the target relative to the beam center direction is... and The calculation formula is: ; ; in, for The slope of the direction angle curve, for The slope of the direction identification curve.

[0017] The present invention also proposes a phased array radar angle measurement system in sinusoidal space for performing any of the methods described above, comprising: The signal receiving and acquisition module is used to receive the echo signal from the phased array antenna and acquire multi-channel analog echo signals. The signal processing module is used to digitize and preprocess the multi-channel analog echo signal to form multi-channel baseband echo data; The range-Doppler image generation module is used to perform pulse compression and coherent accumulation processing on the multi-channel baseband echo data to generate range-Doppler images. The target range and velocity calculation module is used to perform target detection on the range-Doppler map and obtain the range gate index and Doppler channel index of the target, and calculate the target's range and velocity based on the phased array radar system parameters; The complex ratio extraction and calculation module is used to extract the complex data of the multi-channel range gate and Doppler channel index of the detected target, and calculate the complex ratio values ​​of the azimuth difference channel and the sum channel, and the complex ratio values ​​of the pitch difference channel and the sum channel, respectively. The target angle calculation module is used to calculate the sine offset based on the slope of the corresponding angle detection curve, and then calculate the target angle.

[0018] The beneficial effects of this invention are as follows: This invention transforms the angle measurement process from the antenna coordinate system to a sinusoidal space, simplifying the complex angle discrimination curve into a linear translation relationship. The slope of the angle discrimination curve at the same frequency point does not change with the scanning direction; high-precision angle measurement can be achieved simply by storing the slope of the angle discrimination curve corresponding to each frequency point. For radar echoes, initial target separation is first completed through range-Doppler processing and constant false alarm rate detection. Then, the three-channel signals are extracted, and the sinusoidal offset is calculated based on the pre-stored slope of the angle discrimination curve at the current frequency point. The target angle is then directly solved using an explicit expression.

[0019] This method eliminates the need to configure multiple sets of angle discrimination curves as the scanning angle changes at the same frequency point. It only requires pre-storing the slope of the angle discrimination curves according to the frequency point, and high-precision calculation is achieved through explicit expressions during angle measurement. Compared with traditional methods, it eliminates complex processing procedures such as multi-angle segmented calibration, nonlinear fitting, or iterative inversion, and has good engineering practicality, especially suitable for phased array radar systems with multi-frequency points and wide-angle scanning. Attached Figure Description

[0020] Figure 1 This is a flowchart illustrating a phased array radar angle measurement method in sinusoidal space, provided as an embodiment of the present invention.

[0021] Figure 2 This is a schematic diagram of the antenna coordinate system provided in an embodiment of the present invention.

[0022] Figure 3 This is a schematic diagram of the antenna array element arrangement provided in an embodiment of the present invention.

[0023] Figure 4 The transformation relationship between the antenna coordinate system and the sinusoidal coordinate system is provided in the embodiments of the present invention.

[0024] Figure 5 Different beam orientations provided in embodiments of the present invention Direction angle curve.

[0025] Figure 6 Different beam orientations provided in embodiments of the present invention Direction Angle Curve Figure 7 The target detection results for the channel provided in the embodiments of the present invention. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Therefore, the following detailed description of the embodiments of the present invention provided with reference to the accompanying drawings is not intended to limit the scope of protection of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention. The technical solutions of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0027] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning that would be understood by one of ordinary skill in the art to which this invention pertains.

[0028] Example 1 The principle of the angle measurement algorithm in sinusoidal space provided by this invention is as follows: First, define the antenna coordinate system as follows: Figure 2 As shown. The antenna array is located in the XOY plane, and the radio wave propagation direction during transmission is +Z axis. The XYZ coordinate system satisfies the right-hand rule. Antenna coordinate system Defined as: The angle between the beam direction and the +Z axis (pitch angle). The azimuth angle is the angle between the projection of the beam direction onto the XOY plane and the +X axis.

[0029] Antenna array element arrangement diagram as shown Figure 3 As shown. The total number of array elements is The number of elements in the X-direction matrix is The number of elements in the Y-direction matrix is , and These represent the element spacing in the X and Y directions, respectively. The center of the array surface is the origin of the coordinate system. Figure 3 Midpoint P0. For example... Figure 3 As shown, the first The coordinates of each array element can be represented as: (1) in, .

[0030] The antenna array is divided into , , and There are 4 subarrays in total, and the number of array elements in each subarray is... Assume the antenna beam center points in the direction of... If the radiation patterns of all array elements are considered to be consistent, then the radiation pattern of each subarray in sinusoidal space can be represented as: (2) (3) (4) (5) in, , , , , , , λ is the wavelength. and The variable in sinusoidal space represents the spatial direction vector in the antenna coordinate system. The normalized projection components on the array plane correspond to the direction cosines in the X and Y axes, respectively. The mapping relationship from the antenna coordinate system to the sinusoidal space is as follows: Figure 4 As shown. The coordinates of the beam center in sinusoidal space. and yes The offset of the direction relative to the beam center in sinusoidal space.

[0031] The sum and difference beams are generated using the symmetric inversion method. The sum beam pattern is as follows: The azimuth difference beam pattern is The pitch difference beam pattern is .

[0032] The ratio of the azimuth difference beam to the sum beam is: (6) in, Let X be the number of array elements in the X direction. Let Y be the number of array elements in the Y direction. For imaginary units, For wavelength, The spacing between array elements is in the X direction. Let Y be the element spacing in the Y direction. From equation (6), it can be seen that the ratio is only related to... Related. Moreover, within a certain range (usually the main lobe of the antenna beam), the ratio is related to... This can be approximated as a linear relationship. By measuring the sum and azimuth patterns of the phased array antenna, the ratio of the elevation difference pattern to the sum pattern is obtained, thus yielding the angle discrimination curve. A straight line is fitted to an approximately linear segment within the main lobe, and the results are recorded. Slope of the direction angle curve .

[0033] The ratio of the pitch difference beam to the sum beam is: (7) As can be seen from equation (7), the ratio is only related to Related. Moreover, within a certain range (usually the main lobe of the antenna beam), the ratio is related to... This can be approximated as a linear relationship. Measure the sum beam pattern and elevation difference pattern of the phased array antenna, and obtain the ratio of the elevation difference pattern to the sum beam pattern, thus obtaining the angle discrimination curve. Perform straight-line fitting on an approximately linear segment within the main lobe and record the results. Slope of the direction angle curve .so, and It can be represented as: (8) (9) To determine the imaginary part, we can see that in the sinusoidal space... and The directional angle-determining curves are independent and uncoupled. Furthermore, their shape does not change due to antenna beam scanning; they only shift position with the beam scan. Based on these characteristics, only [the following information is recorded]. and This can then be used for angle measurement calculations in subsequent signal processing.

[0034] like Figure 1 The diagram shown is a flowchart illustrating a phased array radar angle measurement method in sinusoidal space according to an embodiment of the present invention. Specific steps include: S101: The phased array antenna receives echo signals and acquires multi-channel analog echo signals.

[0035] S102: Multi-channel signal digitization and preprocessing to generate baseband echo data in three channels: sum, azimuth difference, and elevation difference. Specifically, this includes: The echo signals of the sum, azimuth, and pitch difference channels are sampled and quantized by an analog-to-digital converter to obtain the digital signals of the corresponding channels. Then, digital down-conversion processing is performed to obtain the baseband echo data of each channel.

[0036] S103: Pulse compression and coherent accumulation processing are performed on the baseband echo data of the sum, azimuth difference, and elevation difference channels to obtain three range-Doppler images. Specifically, this includes: A frequency domain correlation method is used to perform matched filtering on the echo data of each channel to achieve range pulse compression. Then, a Fourier transform is performed along the pulse dimension on the pulse-compressed data of each channel to achieve coherent accumulation. Finally, three range-Doppler images are obtained.

[0037] S104: Perform target detection on the range-Doppler image and obtain the target's range gate and Doppler channel index. Calculate the target's range and velocity based on the phased array radar system parameters. Specifically, this includes: In this embodiment, a constant false alarm rate (CFAR) detection algorithm is used for target detection. The power of each point in the range-Doppler image is compared with a threshold. Points that exceed the threshold are identified as targets, and their corresponding range gate index and Doppler channel index are recorded.

[0038] Based on the phased array radar system parameters, establish the correspondence between the range gate index and the target range, as well as the correspondence between the Doppler channel index and the target velocity, and obtain the target's range and radial velocity information accordingly.

[0039] S105: For the detected target, extract the complex data of the sum of the range gate and Doppler channel indices, as well as the azimuth and pitch difference channels. Calculate the complex ratios of the azimuth difference channel and the sum channel, and the complex ratios of the pitch difference channel and the sum channel, respectively. Calculate the sinusoidal offset based on the slope of the corresponding angle discrimination curve, and then calculate the angle corresponding to the target. Specifically, this includes the following steps: First, based on the target distance gate index and Doppler channel index obtained in S104, the complex values ​​corresponding to the target are extracted from the range-Doppler images generated in S103 for the channel, azimuth difference, and elevation difference. , ,and .

[0040] Then, calculate the ratio of the target's azimuth difference, pitch difference, and channel distance. and And take the imaginary part.

[0041] Next, based on the slope of the angle curve and Based on equations (8) and (9), the sinusoidal offset of the target relative to the beam center direction is calculated. and The true sinusoidal quantity of the target and It can be obtained using the following formula.

[0042] (10) Finally, the target angle can be obtained as follows: (11) (12) The following section verifies the phased array radar angle measurement method in sinusoidal space provided by the present invention through simulation experiments.

[0043] The specific operating parameters of the radar are shown in Table 1.

[0044] Table 1

[0045] Different beam directions Direction angle curves such as Figure 5 As shown, different beam directions Direction angle curves such as Figure 6 As shown, the angle curve in the sinusoidal space is linearly shifted only as the scanning angle changes.

[0046] Next, a simulation of target detection is performed, and the target parameters are shown in Table 2.

[0047] Table 2

[0048] The radar phased array antenna beam center points at [10, 10]°. The simulation sets the signal-to-noise ratio to 15dB after coherent accumulation, and the channel target detection results are as follows: Figure 7 As shown, the target distances were measured to be 50km and 53km, and the speeds were 14.73m / s and 17.41m / s, respectively.

[0049] Table 3 shows the angle measurement results for the two targets. It can be seen that the method described in this invention can achieve high-precision angle measurement of the targets.

[0050] Table 3

[0051] Example 2 A phased array radar angle measurement method in sinusoidal space includes: Step S101: The phased array antenna receives the echo signal and acquires multi-channel analog echo signals; Step S102: Digitize and preprocess the multi-channel analog echo signal to form multi-channel baseband echo data; Step S103: Perform pulse compression and coherent accumulation processing on the multi-channel baseband echo data respectively to generate a range-Doppler map; Step S104: Perform target detection on the range-Doppler image and obtain the range gate index and Doppler channel index of the target. Calculate the target's range and velocity based on the phased array radar system parameters. Step S105: For the detected target, extract the complex data of the multi-channels of the range gate and Doppler channel index, calculate the complex ratio of the azimuth difference channel and the sum channel, and the complex ratio of the pitch difference channel and the sum channel, respectively, calculate the sinusoidal offset according to the slope of the corresponding angle discrimination curve, and calculate the target angle.

[0052] According to the phased array radar angle measurement method of the present invention, the multi-channel includes: an azimuth channel, an azimuth difference channel, and an elevation difference channel.

[0053] According to the phased array radar angle measurement method of the present invention, step S102 specifically includes: The echo signals of the sum, azimuth, and pitch difference channels are sampled and quantized by an analog-to-digital converter to obtain the digital signals of the corresponding channels. Then, digital down-conversion processing is performed to obtain the baseband echo data of each channel.

[0054] According to the phased array radar angle measurement method of the present invention, step S103 specifically includes: Matched filtering is performed on the echo data of each channel to achieve range pulse compression; Fourier transform is performed along the pulse dimension on the pulse-compressed data of each channel to achieve coherent accumulation and obtain the range-Doppler map.

[0055] According to the phased array radar angle measurement method of the present invention, step S104 specifically includes: A preset algorithm is used to perform target detection with the range-Doppler map. The power of each point in the range-Doppler map is compared with a threshold. Points that exceed the threshold are identified as targets. The corresponding range gate index and Doppler channel index are recorded. The range and velocity information of the target are calculated based on the phased array radar system parameters.

[0056] According to the phased array radar angle measurement method of the present invention, the preset algorithm is a constant false alarm rate (CFAR) detection algorithm.

[0057] According to the phased array radar angle measurement method of the present invention, step S105 specifically includes: Based on the target's range gate index and Doppler channel index, extract the target's corresponding complex values ​​from the range-Doppler maps of the sum channel, azimuth channel, and pitch difference channel, respectively. , and ; Calculate the target azimuth difference, pitch difference, and the complex ratio of the channel. and And take the imaginary part; Based on the slope of the angle curve and The sinusoidal offset of the target relative to the beam center direction is calculated. and The true sinusoidal quantity of the target and It can be obtained from the following formula: ; Calculate the target angle, and the formula for calculating the target angle is: ; .

[0058] According to the phased array radar angle measurement method of the present invention, the calculation of target azimuth difference, elevation difference, and complex ratio of the channel is described. and The calculation formula is: ; ; in, The spacing between array elements is in the X direction. The spacing between array elements in the Y direction. and yes The offset of the direction relative to the beam center in sinusoidal space.

[0059] According to the phased array radar angle measurement method of the present invention, the sinusoidal offset of the target relative to the beam center direction is... and The calculation formula is: ; ; in, for The slope of the direction angle curve, for The slope of the direction identification curve.

[0060] Example 3 A phased array radar angle measurement system in sinusoidal space, used to perform any of the methods described above, comprising: The signal receiving and acquisition module is used to receive the echo signal from the phased array antenna and acquire multi-channel analog echo signals. The signal processing module is used to digitize and preprocess the multi-channel analog echo signal to form multi-channel baseband echo data; The range-Doppler image generation module is used to perform pulse compression and coherent accumulation processing on the multi-channel baseband echo data to generate range-Doppler images. The target range and velocity calculation module is used to perform target detection on the range-Doppler map and obtain the range gate index and Doppler channel index of the target, and calculate the target's range and velocity based on the phased array radar system parameters; The complex ratio extraction and calculation module is used to extract the complex data of the multi-channel range gate and Doppler channel index of the detected target, and calculate the complex ratio values ​​of the azimuth difference channel and the sum channel, and the complex ratio values ​​of the pitch difference channel and the sum channel, respectively. The target angle calculation module is used to calculate the sine offset based on the slope of the corresponding angle detection curve, and then calculate the target angle.

[0061] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention do not depart from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A phased array radar angle measurement method in sinusoidal space, comprising: Step S101: The phased array antenna receives the echo signal and acquires multi-channel analog echo signals; Step S102: Digitize and preprocess the multi-channel analog echo signal to form multi-channel baseband echo data; the multi-channel includes: a sum channel, an azimuth difference channel, and an elevation difference channel; Step S103: Perform pulse compression and coherent accumulation processing on the multi-channel baseband echo data respectively to generate a range-Doppler map; Step S104: Perform target detection on the range-Doppler image and obtain the range gate index and Doppler channel index of the target. Calculate the target's range and velocity based on the phased array radar system parameters. Step S105: For the detected target, extract the complex data of the multi-channel range gate and Doppler channel index, calculate the complex ratio of the azimuth difference channel and the sum channel, and the complex ratio of the pitch difference channel and the sum channel respectively. Calculate the sinusoidal offset based on the slope of the corresponding angle discrimination curve, and calculate the target angle. Step S105 specifically includes: Based on the target's range gate index and Doppler channel index, extract the target's complex values ​​from the range-Doppler images of the sum channel, azimuth channel, and elevation channel, respectively. , and ; Calculate the target azimuth difference, pitch difference, and the complex ratio of the channel. and And take the imaginary part; Based on the slope of the angle curve and The sinusoidal offset of the target relative to the beam center direction is calculated. and The true sinusoidal quantity of the target and The calculation formula is: ； ； ； in, The direction of the antenna beam center; The formula for calculating the target angle is: ； ； The calculation of the target azimuth difference, elevation difference, and the complex ratio of the channel are described. and The calculation formula is: ； ； in, Let X be the number of array elements in the X direction. Let Y be the number of array elements in the Y direction. For virtual part units, For wavelength, The spacing between array elements is in the X direction. The spacing between array elements in the Y direction. and yes The offset of the direction relative to the beam center in sinusoidal space; The sinusoidal offset of the target relative to the beam center direction and The calculation formula is: ； ； in, To perform imaginary part operations, for The slope of the direction angle curve, for The slope of the direction angle curve.

2. The phased array radar angle measurement method according to claim 1, characterized in that, Step S102 specifically includes: The echo signals of the sum, azimuth, and pitch difference channels are sampled and quantized by an analog-to-digital converter to obtain the digital signals of the corresponding channels. Then, digital down-conversion processing is performed to obtain the baseband echo data of each channel.

3. The phased array radar angle measurement method according to claim 1, characterized in that, Step S103 specifically includes: Matched filtering is performed on the echo data of each channel to achieve range pulse compression; Fourier transform is performed along the pulse dimension on the pulse-compressed data of each channel to achieve coherent accumulation and obtain the range-Doppler map.

4. The phased array radar angle measurement method according to claim 1, characterized in that, Step S104 specifically includes: A preset algorithm is used to perform target detection on the range-Doppler map. The power of each point in the range-Doppler map is compared with a threshold. Points that exceed the threshold are identified as targets. The corresponding range gate index and Doppler channel index are recorded. The range and velocity information of the target are calculated based on the phased array radar system parameters.

5. The phased array radar angle measurement method according to claim 4, characterized in that, The preset algorithm is a constant false alarm rate (CFAR) detection algorithm.

6. A phased array radar angle measurement system in sinusoidal space, used to perform the method according to any one of claims 1-5, characterized in that, include: The signal receiving and acquisition module is used to receive the echo signal from the phased array antenna and acquire multi-channel analog echo signals. The signal processing module is used to digitize and preprocess the multi-channel analog echo signal to form multi-channel baseband echo data; The range-Doppler image generation module is used to perform pulse compression and coherent accumulation processing on the multi-channel baseband echo data to generate range-Doppler images. The target range and velocity calculation module is used to perform target detection on the range-Doppler map and obtain the range gate index and Doppler channel index of the target, and calculate the target's range and velocity based on the phased array radar system parameters; The complex ratio extraction and calculation module is used to extract the complex data of the multi-channel range gate and Doppler channel index of the detected target, and calculate the complex ratio values ​​of the azimuth difference channel and the sum channel, and the complex ratio values ​​of the pitch difference channel and the sum channel, respectively. and The target angle calculation module is used to calculate the sinusoidal offset based on the slope of the corresponding angle detection curve, and then calculate the target angle. Based on the target's range gate index and Doppler channel index, extract the target's complex values ​​from the range-Doppler images of the sum channel, azimuth channel, and elevation channel, respectively. , and ; Calculate the target azimuth difference, pitch difference, and the complex ratio of the channel. and And take the imaginary part; Based on the slope of the angle curve and The sinusoidal offset of the target relative to the beam center direction is calculated. and The true sinusoidal quantity of the target and The calculation formula is: ； ； ； in, The direction of the antenna beam center; The formula for calculating the target angle is: ； ； The calculation of the target azimuth difference, elevation difference, and the complex ratio of the channel are described. and The calculation formula is: ； ； in, Let X be the number of array elements in the X direction. Let Y be the number of array elements in the Y direction. For virtual part units, For wavelength, The spacing between array elements is in the X direction. The spacing between array elements in the Y direction. and yes The offset of the direction relative to the beam center in sinusoidal space; The sinusoidal offset of the target relative to the beam center direction and The calculation formula is: ； ； in, To perform imaginary part operations, for The slope of the direction angle curve, for The slope of the direction angle curve.

Images