Projectile drop point detection method and system based on L-shaped receiving antenna array

Abstract

The invention discloses a projectile drop point detection method based on an L-shaped receiving antenna array. The method comprises the following steps: receiving an echo signal by using the L-shaped receiving antenna array; the L-shaped receiving antenna array comprises a first uniform linear array arranged in the horizontal direction and a second uniform linear array arranged in the vertical direction; performing digital beam forming on the echo signal; distance dimension and Doppler dimension CFAR detection is carried out according to the sum beam, trace point condensation processing is carried out, and a target trace point is obtained; performing target distance estimation and Doppler velocity estimation according to the target trace point to obtain a parameter estimation result; performing target matching according to the target trace point and the parameter estimation result, performing sum-difference angle measurement according to the target matching result to realize target angle estimation, and obtaining a final target detection result; and obtaining ballistic trajectory estimation according to a final target detection result, and extrapolating an estimated impact point according to a ballistic trajectory estimation result to realize projectile drop point detection. According to the method, the real-time requirement can be met in a multi-target scene, and the cost is relatively low.

Description

Technical Field

[0001] The invention belongs to the field of radar, and in particular relates to a projectile landing point detection method and system based on an L-shaped receiving antenna array. Background Art

[0002] In the live-fire shooting test at the shooting range, for the task requirements of detection, characteristic measurement and landing point prediction of high-speed projectile targets, combined with the real-time measurement and reporting of the shooting range as well as personnel and environmental safety factors, it is of great significance to study detection equipment with the characteristics of wide coverage, all-weather, all-day, fully automatic detection, high-precision landing point positioning, remote control and automatic real-time reporting.

[0003] In order to solve the problem of using radar to measure the terminal trajectory of projectiles and estimate the landing point, Chen Jianwei from Nanjing University of Science and Technology proposed a system based on a search and track (TAS) phased array radar in the paper "Research on the Rapid Prediction Method of Gun Position and Landing Point Based on Radar Measurement". The system searches for airborne projectile targets in search mode, tracks the searched targets through the pitch tracking beam to obtain the target parameters of the air warhead, and estimates the landing point of the projectile through the method of correlation prediction and extrapolation estimation. However, this method requires mode switching between search mode and tracking mode, and resource scheduling of tracking beams. Scheduling in multi-target scenarios is difficult to meet real-time requirements and is costly.

[0004] Yin Xiaohu et al. proposed a "staring radar method for measuring descent trajectory", which proposed a staring radar system with a transmitting antenna emitting a wide beam, a receiving antenna using a 2*2 array, and manually adjustable antenna elevation and azimuth. The radar system detects and estimates parameters of targets, accurately measures the trajectory of the descent phase (terminal phase) of the warhead based on the parameter estimation results, and estimates the impact point through a particle trajectory model. However, in this method, the receiving antenna array adopts a planar array design, and the number of receiving components and the system scale are relatively complex, which cannot be used for detection in high-speed multi-target scenarios.

[0005] Li Bin and others proposed the "L-shaped transceiver array antenna front end and its signal processing method", and proposed the front-end design and corresponding signal processing method for short-range high-speed target detection using an obliquely polarized L-shaped array receiving antenna. However, this method uses the transmitting antenna beamforming in the design of the transmitting part, and the system design is complex. The time resource consumption for search and multi-target tracking is large, and it is also difficult to meet the needs of short-range high-speed multi-target detection and landing point detection.

[0006] In summary, there is an urgent need for a projectile landing point detection solution that can meet real-time requirements and has low cost in multi-target scenarios. Summary of the invention

[0007] In order to solve the above problems existing in the prior art, the present invention provides a projectile landing point detection method and system based on an L-shaped receiving antenna array.

[0008] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0009] A projectile landing point detection method based on an L-shaped receiving antenna array, comprising:

[0010] An L-shaped receiving antenna array configured on a staring radar is used to receive an echo signal; the L-shaped receiving antenna array includes a first uniform linear array arranged in a horizontal direction and a second uniform linear array arranged in a vertical direction; the echo signal is an echo of a wide beam emitted by a transmitting antenna of the staring radar; the width of the wide beam is sufficient to cover the azimuth and elevation dimensions of a detection area;

[0011] Simultaneously performing digital beamforming of multiple groups of receiving beams on the echo signals received by the first uniform linear array and the echo signals received by the second uniform linear array, each group of receiving beams including a sum beam and a difference beam;

[0012] For the sum beams of the first uniform linear array and the second uniform linear array, CFAR detection in the range dimension and the Doppler dimension is performed respectively, and point trace condensation processing is performed on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction;

[0013] Perform target distance estimation and Doppler velocity estimation according to the first target point trace and the second target point trace respectively, to obtain a first parameter estimation result in the horizontal direction and a second parameter estimation result in the vertical direction;

[0014] Performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result, and the second parameter estimation result, and performing sum and difference angle measurement according to the target matching result to achieve target angle estimation, so as to obtain a final target detection result;

[0015] The ballistic trajectory estimation is obtained according to the final target detection result, and the impact point is estimated by extrapolation according to the ballistic trajectory estimation result to realize the projectile landing point detection.

[0016] Optionally, the transmitting antenna is a left-hand circularly polarized antenna, and the transmitting antenna uses a Ku-band continuous wave to transmit the wide beam; and the antennas in the L-shaped receiving antenna array are all right-hand circularly polarized antennas.

[0017] Optionally, for the sum beams of the first uniform linear array and the second uniform linear array, CFAR detection in the range dimension and the Doppler dimension is performed respectively thereon, and point trace condensation processing is performed on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction, including:

[0018] Performing range-dimensional FFT and moving target detection processing on each group of receiving beams of the first uniform linear array and the second uniform linear array to obtain a range Doppler spectrum of each group of receiving beams; wherein the range Doppler spectrum of each group of receiving beams includes a range Doppler spectrum of a sum beam and a range Doppler spectrum of a difference beam;

[0019] Performing range-dimension unit average CFAR detection and Doppler-dimension unit average CFAR detection on the range-Doppler spectrum of the sum beam of the first uniform linear array to obtain a range-dimension CFAR result matrix and a Doppler-dimension CFAR result matrix in the horizontal direction, and performing range-dimension unit average CFAR detection and Doppler-dimension unit average CFAR detection on the range-Doppler spectrum of the sum beam of the second uniform linear array to obtain a range-dimension CFAR result matrix and a Doppler-dimension CFAR result matrix in the vertical direction;

[0020] Performing an AND operation on the distance dimension CFAR result matrix and the Doppler dimension CFAR result matrix in the horizontal direction to obtain the CFAR post-processing result matrix in the horizontal direction, and performing an AND operation on the distance dimension CFAR result matrix and the Doppler dimension CFAR result matrix in the vertical direction to obtain the CFAR post-processing result matrix in the vertical direction;

[0021] The CFAR post-processing result matrix in the horizontal direction is subjected to point condensation processing to obtain the first target point trace in the horizontal direction, and the CFAR post-processing result matrix in the vertical direction is subjected to point condensation processing to obtain the second target point trace in the vertical direction.

[0022] Optionally, the point trace condensation processing is implemented by using a mass center condensation method.

[0023] Optionally, performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result, and the second parameter estimation result includes:

[0024] Obtaining the target distance and Doppler velocity corresponding to each point in the one target point trace from the first parameter estimation result, and obtaining the target distance and Doppler velocity corresponding to each point in the two target point traces from the second parameter estimation result;

[0025] A point in the first target point trace and the second target point trace where the target distance and the Doppler velocity are the same is determined as a target.

[0026] Optionally, obtaining a ballistic trajectory estimate according to the final target detection result includes:

[0027] According to the final target detection result, a logic method is used to extract potential target tracks;

[0028] According to the extracted potential target tracks, the nearest neighbor NN algorithm or graph nearest neighbor GNN algorithm is used for track association, and the Kalman filter algorithm is used for track filtering;

[0029] According to the track filtering results, the scoring method is used to manage the track and realize the ballistic trajectory estimation.

[0030] The present invention also provides a projectile landing point detection system based on an L-shaped receiving antenna array, comprising: a staring radar and a projectile landing point detection module;

[0031] The staring radar transmits a wide beam through its transmitting antenna; the width of the wide beam is sufficient to cover the azimuth and elevation dimensions of the detection area;

[0032] The staring radar receives the wide beam echo signal through its L-shaped receiving antenna array; the L-shaped receiving antenna array includes a first uniform linear array arranged in a horizontal direction and a second uniform linear array arranged in a vertical direction;

[0033] The projectile landing point detection module is used to implement the following method steps:

[0034] Simultaneously performing digital beamforming of multiple groups of receiving beams on the echo signals received by the first uniform linear array and the echo signals received by the second uniform linear array, each group of receiving beams including a sum beam and a difference beam;

[0035] For the sum beams of the first uniform linear array and the second uniform linear array, CFAR detection in the range dimension and the Doppler dimension is performed respectively, and point trace condensation processing is performed on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction;

[0036] Perform target distance estimation and Doppler velocity estimation according to the first target point trace and the second target point trace respectively, to obtain a first parameter estimation result in the horizontal direction and a second parameter estimation result in the vertical direction;

[0037] Performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result, and the second parameter estimation result, and performing sum and difference angle measurement according to the target matching result to achieve target angle estimation, so as to obtain a final target detection result;

[0038] The ballistic trajectory estimation is obtained according to the final target detection result, and the impact point is estimated by extrapolation according to the ballistic trajectory estimation result to realize the projectile landing point detection.

[0039] Optionally, the system further comprises: a two-dimensional servo turntable and a tripod;

[0040] The two-dimensional servo turntable is used to realize a rotation of 0 to 360° in the horizontal direction and an adjustment of the pitch angle of -30° to 30°; the radar is installed on the two-dimensional servo turntable, and the azimuth and pitch direction of the radar array are changed along with the two-dimensional servo turntable; the radar array includes the transmitting antenna and the L-shaped receiving antenna array; the two-dimensional servo turntable is fixed on the tripod.

[0041] Optionally, the radar array comprises: a panel, the transmitting antenna, the L-shaped receiving antenna array and a transceiver isolation baffle; the transceiver isolation baffle comprises a horizontal isolation baffle and a vertical isolation baffle;

[0042] The horizontal isolation baffle is located between the transmitting antenna and the first uniform linear array of the L-shaped receiving antenna array, and is arranged close to the transmitting antenna; the vertical isolation baffle is located between the transmitting antenna and the second uniform linear array of the L-shaped receiving antenna array, and is arranged close to the transmitting antenna.

[0043] Optionally, the hardware components of the staring radar include: R frequency conversion components, lightning control board, frequency synthesis board, inclinometer board, Beidou board and antenna, wireless network board and antenna, and processing board;

[0044] The R frequency conversion component is connected to the receiving antenna in the L-shaped receiving antenna array by blind plugging, so as to perform down-conversion processing of the signal;

[0045] The radar control board is used to control the operation of the radar;

[0046] The frequency synthesizer board is responsible for the generation of the clock signal, the generation of the signal waveform of the wide beam and the up-conversion work, and provides the local oscillator signal for the down-conversion of the R frequency conversion component;

[0047] The inclinometer board is used to provide the array roll angle and pitch angle information;

[0048] The Beidou board and its antenna are used to receive and analyze the data received by the Beidou antenna, and provide latitude, longitude, altitude and azimuth information;

[0049] The wireless network card and antenna are used to realize wireless communication between the system and external devices;

[0050] The processing board is used to implement AD sampling and signal processing; the signal processing includes the method steps for implementing the projectile landing point detection module.

[0051] The projectile landing point detection method based on the L-shaped receiving antenna array provided by the present invention adopts a staring radar, and both the transmitting beam and the receiving beam are fixed beams irradiating a fixed area, and no complicated search and tracking beam scheduling is required, which reduces the complexity of the radar system, can meet the real-time requirements in a multi-target scenario, and has lower system development and manufacturing costs. The present invention uses an L-shaped receiving antenna array. Compared with a phased array, the present invention can reduce the number of receiving components and the system scale, while still achieving the same azimuth and elevation angular measurement accuracy, and simultaneously forms a digital multi-beam receiving target echo signal, and the receiving beam has a wide coverage range and excellent high-speed target detection performance.

[0052] The present invention will be further described in detail below with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 It is a flow chart of a projectile landing point detection method based on an L-shaped receiving antenna array provided by an embodiment of the present invention;

[0054] Figure 2 The signal processing flow for obtaining the final target detection result in an embodiment of the present invention is exemplarily shown;

[0055] Figure 3 The signal processing flow of estimating the ballistic trajectory and extrapolating the estimated impact point to realize the projectile landing point detection in the embodiment of the present invention is exemplarily shown;

[0056] Figure 4 A schematic diagram of the appearance structure of a projectile landing point detection system based on an L-shaped receiving antenna array provided in an embodiment of the present invention;

[0057] Figure 5 A schematic diagram of a transceiver antenna of a projectile landing point detection system based on an L-shaped receiving antenna array provided in an embodiment of the present invention;

[0058] Figure 6 A schematic diagram of the hardware structure of a projectile landing point detection system based on an L-shaped receiving antenna array provided in an embodiment of the present invention;

[0059] Figure 7 The experimental results of verifying the projectile landing point detection system provided by the embodiment of the present invention are shown. DETAILED DESCRIPTION

[0060] The present invention is further described in detail below with reference to specific embodiments, but the embodiments of the present invention are not limited thereto.

[0061] In view of the problems that the resource scheduling of the existing phased array radar system used for descent trajectory measurement is too complicated, the scheduling in multi-target scenarios is difficult to meet the real-time requirements and the cost is high, and the detection capability of fast and large-scale projectile targets is insufficient, the embodiment of the present invention provides a projectile drop point detection method based on an L-shaped receiving antenna array, which adopts a new staring continuous wave radar system, transmits a wide beam, and arranges a one-dimensional receiving linear array with multiple array elements in the horizontal and vertical directions to form an L-shaped receiving antenna array. The digital beam forming (DBF) technology is used to simultaneously form multiple receiving narrow beams in the azimuth and elevation dimensions, respectively detect and process the two-dimensional receiving echoes, match the targets detected by the two-dimensional array antenna, and perform correlation filtering on the matched target parameters to obtain the projectile target trajectory, and then extrapolate to realize the drop point detection system of the impact point estimation, so as to achieve high-precision projectile target trajectory measurement and impact point estimation at a low system cost. The following is a detailed description of the projectile drop point detection method based on an L-shaped receiving antenna array provided by the embodiment of the present invention.

[0062] See also Figure 1 to Figure 3 The projectile landing point detection method based on the L-shaped receiving antenna array provided in the embodiment of the present invention comprises the following steps:

[0063] S10. Receive the echo signal using an L-shaped receiving antenna array configured on the staring radar; the L-shaped receiving antenna array includes a first uniform linear array arranged in the horizontal direction and a second uniform linear array arranged in the vertical direction; the echo signal is an echo of a wide beam emitted by the transmitting antenna of the staring radar; the width of the wide beam is sufficient to cover the azimuth and elevation dimensions of the detection area.

[0064] The first uniform linear array and the second uniform linear array both include a plurality of receiving array elements, each of which is connected to a digital signal processing channel, for sequentially performing down-conversion, analog-to-digital conversion (sampling), and digital mixing processing on the echo signal received by the receiving antenna, thereby obtaining a baseband signal with echo information, and subsequent processing processes are all performed using the baseband signal as the echo signal. The sampling frequency should be high enough to ensure that the high-frequency components of the target are captured.

[0065] Specifically, the transmitting antenna uses Ku-band continuous wave to transmit a wide beam. For a linear frequency modulated continuous wave radar, its transmitting signal is expressed as:

[0066] s(t)=cos(2πf c t+πμt 2 );

[0067] Among them, f c is the transmitting frequency, μ is the frequency modulation slope, and t represents the time.

[0068] Correspondingly, the echo signal received by the radar is expressed as:

[0069] s r (t) = cos(2πf c (t-t0)+πμ(t-t0) 2 ;

[0070] Among them, t0 is the echo delay.

[0071] Then, the linear frequency modulated continuous wave is de-sloped to obtain the intermediate frequency signal:

[0072] s IF (t) = LPF{s(t)s r (t)};

[0073] Wherein, LPF{·} represents the de-skew operation.

[0074] Then, the intermediate frequency signal is Hilbert transformed into a complex exponential signal, that is, the baseband signal is obtained.

[0075] Preferably, in one implementation, the transmitting antenna may be a left-hand circularly polarized antenna, and the antenna in the L-shaped receiving antenna array may be a right-hand circularly polarized antenna. Thus, compared with the design of co-polarized transmitting and receiving antennas, the present invention can effectively avoid the problem of insufficient transmitting and receiving isolation, and reduce the complexity and related overhead of the design of the transmitting and receiving isolation part.

[0076] S20, performing digital beamforming of multiple groups of receiving beams on the echo signals received by the first uniform linear array and the echo signals received by the second uniform linear array simultaneously, each group of receiving beams including a sum beam and a difference beam.

[0077] Specifically, a fixed beamforming method is used to simultaneously perform digital beamforming of multiple groups of receiving beams on the echo signals received by the first uniform linear array and the echo signals received by the second uniform linear array. For a one-dimensional linear array, the signal received by each array element can be expressed as x n (t), where n represents the nth array element. The received signal vector of a one-dimensional linear array with N array elements can be expressed as:

[0078] X(t)=[x1(t),x2(t),...,x N (t)] T ;

[0079] The superscript T indicates the matrix transpose.

[0080] In fixed beamforming, assuming that the beam pointing direction is θ, the steering vector in this direction for the N-element linear array is:

[0081] W(n)=[w1,w2,...,wN ]=[1,e j2πdsinθ / λ ,...,e (N-1)j2πdsinθ / λ ];

[0082] Where d represents the array element spacing, θ represents the beam pointing direction, λ represents the radar emission wavelength, and e represents the natural base.

[0083] The DBF output obtained by weighting the received signal vector and the steering vector is:

[0084]

[0085] By changing different beam pointing directions θ, multiple groups of DBF outputs y(t) at different beam pointing directions θ can be obtained.

[0086] Then, a Taylor window is added to each group of steering vectors to generate a sum beam DBF weight coefficient, and a Bayliss window is added to each group of steering vectors to generate a difference beam DBF weight coefficient. Based on the sum beam DBF weight coefficient and the difference beam DBF weight coefficient, the beamforming steering vectors are weighted to obtain multiple groups of receiving beams when different beams are pointed at θ.

[0087] In step S20, a fixed beam forming method is adopted to form a receiving beam in a predetermined direction, and dynamic adjustment is performed independently of the received signal. A fixed steering vector weight is adopted. For the horizontal subarray, the half-power beam width of each receiving beam formed by DBF is narrower in the azimuth dimension and wider in the elevation dimension. For the vertical subarray, the half-power beam width of each receiving beam formed by DBF is wider in the azimuth dimension and narrower in the elevation dimension. That is, each receiving beam of the horizontal subarray is a wide beam in the elevation dimension and a narrow beam in the azimuth dimension, and each receiving beam of the vertical subarray is a wide beam in the azimuth dimension and a narrow beam in the elevation dimension.

[0088] The digital beamforming process in the present invention is essentially to perform multi-beamforming processing on two one-dimensional linear arrays at the same time. Compared with the two-dimensional array digital beamforming, the processing operation of the present invention is small, has good real-time performance, has low hardware performance requirements, and is easy to implement in engineering. Compared with the two-dimensional phased array radar that uses azimuth and elevation beam scanning to detect and track projectile targets, its transmission and reception are both narrow beams, and multiple beams need to be emitted in different azimuths and elevations to achieve effective coverage of the detection area. Then, according to the direction of target movement, a search screen is set, and a confirmation beam is emitted after the target is intercepted, and tracking is performed at a certain data rate. For high-speed projectile targets in large airspace, the target has less than 1 second from discovery to landing in the effective coverage area, making it impossible for systems of this type to detect and track targets, and it is even more difficult to meet the detection needs of multiple targets.

[0089] S30, performing CFAR detection in the range dimension and the Doppler dimension on the sum beams of the first uniform linear array and the second uniform linear array, and performing point condensation processing on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction.

[0090] Specifically, step S30 includes the following sub-steps:

[0091] (3-1) performing range-dimensional FFT and moving target detection processing on each group of receiving beams of the first uniform linear array and the second uniform linear array to obtain a range Doppler spectrum of each group of receiving beams; wherein the range Doppler spectrum of each group of receiving beams includes a range Doppler spectrum of a sum beam and a range Doppler spectrum of a difference beam;

[0092] (3-2) performing distance dimension unit average CFAR detection and Doppler dimension unit average CFAR detection on the range Doppler spectrum of the sum beam of the first uniform linear array to obtain a distance dimension CFAR result matrix and a Doppler dimension CFAR result matrix in the horizontal direction, and performing distance dimension unit average CFAR detection and Doppler dimension unit average CFAR detection on the range Doppler spectrum of the sum beam of the second uniform linear array to obtain a distance dimension CFAR result matrix and a Doppler dimension CFAR result matrix in the vertical direction;

[0093] (3-3) Performing an AND operation on the distance dimension CFAR result matrix and the Doppler dimension CFAR result matrix in the horizontal direction to obtain the CFAR post-processing result matrix in the horizontal direction, and performing an AND operation on the distance dimension CFAR result matrix and the Doppler dimension CFAR result matrix in the vertical direction to obtain the CFAR post-processing result matrix in the vertical direction;

[0094] (3-4) Performing point condensation processing on the CFAR post-processing result matrix in the horizontal direction to obtain the first target point trace in the horizontal direction, and performing point condensation processing on the CFAR post-processing result matrix in the vertical direction to obtain the second target point trace in the vertical direction.

[0095] It is understandable that after completing the CFAR post-processing (AND operation), a series of detected target points or clutter points are usually obtained, and the points can be aggregated together by performing point trace aggregation processing. Preferably, the point trace aggregation processing can be implemented by using the mass center aggregation method, and the result of the point trace aggregation is the target point trace.

[0096] S40, performing target distance estimation and Doppler velocity estimation according to the first target point trace and the second target point trace respectively, to obtain a first parameter estimation result in the horizontal direction and a second parameter estimation result in the vertical direction.

[0097] Specifically, assume that in the target point trace, the frequency f caused by the target distance target The corresponding kthtarget With the frequency of the spectrum line, then:

[0098]

[0099] Among them, F s is the sampling frequency, and L is the number of sampling points in the fast time dimension. Therefore, if the spectral line position k of the target is known target , the target distance can be derived from this:

[0100]

[0101] Where K is the frequency modulation slope of the FMCW and c is the speed of light.

[0102] The Doppler velocity estimation of the target is achieved by:

[0103] Assume that in the target trace, the frequency caused by the target's velocity v is Corresponding to p target The frequency of the root line is:

[0104]

[0105] Where M is the number of sampling points in the slow time dimension, T c is the period of the linear frequency modulated continuous wave, and λ is the radar emission wavelength. Therefore, if the position p of the target in the Doppler dimension is known (taking the target far away from the radar as an example), target , the Doppler velocity of the target can be derived:

[0106]

[0107] S50, performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result and the second parameter estimation result, and performing sum and difference angle measurement according to the target matching result to achieve target angle estimation, and obtain a final target detection result.

[0108] Wherein, performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result and the second parameter estimation result includes:

[0109] (5-1) obtaining a target distance and a Doppler velocity corresponding to each point in a target point trace from the first parameter estimation result, and obtaining a target distance and a Doppler velocity corresponding to each point in a second target point trace from the second parameter estimation result;

[0110] (5-2) The point in the first target point trace and the second target point trace where the target distance and Doppler velocity are the same is determined as the target.

[0111] Therefore, which points in the first target point trace and the second target point trace correspond to the target has been determined. Then, the azimuth angle and pitch angle of the target detected by the first uniform linear array and the second uniform linear array are estimated by sum and difference angle measurement, respectively, so as to obtain the azimuth angle and pitch angle of the target. Specifically, the receiving beam of the first uniform linear array contains the target azimuth parameter information, and the receiving beam of the first uniform linear array contains the target pitch angle parameter information. Therefore, based on the receiving beam of the first uniform linear array, by comparing the ratio of the difference beam with the angle discrimination curve, the target azimuth angle estimation of the first uniform linear array can be obtained; based on the receiving beam of the second uniform linear array, by comparing the ratio of the difference beam with the angle discrimination curve, the target pitch angle estimation of the second uniform linear array can be obtained. Therefore, the final target detection result includes the distance, speed, azimuth angle and pitch angle of the target.

[0112] S60, obtaining a ballistic trajectory estimation according to the final target detection result, and extrapolating and estimating the impact point according to the ballistic trajectory estimation result to achieve projectile landing point detection.

[0113] Specifically, according to the target point track included in the target matching result, coordinate transformation is performed, and the spherical coordinate parameters of the target parameter estimation are converted into rectangular coordinate parameters. According to the coordinate transformation result, the spatial velocity of the projectile target is obtained by distance differential calculation, and the track start confirmation, track association, track filtering and track management of the point track are completed according to the target parameters to obtain the ballistic trajectory filtering value of the projectile flying target, which is reported to the host computer software for displaying the projectile trajectory. Then, the terminal ballistic trajectory filtering value is coordinate transformed from the radar array rectangular coordinate system to the Northeast Sky (ENU) rectangular coordinate system. According to the coordinate transformation result, the extrapolation estimation is performed based on the particle uniform acceleration model to obtain the impact point estimation result.

[0114] In the embodiment of the present invention, the radar beam can effectively cover the near-ground range. When the trajectory of the end of the descent section outside the beam is extrapolated and estimated, the atmospheric environment and the force characteristics of the projectile are relatively stable. The projectile target can be regarded as a particle. The trajectory outside the radar beam is extrapolated and estimated through the uniform acceleration motion model of the particle, and its intersection with the ground plane is calculated to obtain the impact point estimation result.

[0115] Optionally, in one implementation, obtaining a ballistic trajectory estimate according to the final target detection result includes:

[0116] (6-1) Based on the final target detection results, the logical method is used to extract potential target tracks.

[0117] Specifically, a logic method is used to extract potential target tracks by processing the final target detection results obtained by multiple radar detections.

[0118] (6-2) Based on the extracted potential target tracks, the NN (nearest neighbor) algorithm or the GNN (graph nearest neighbor) algorithm is used for track association, and the Kalman filter algorithm is used for track filtering.

[0119] Here, track association is to associate confirmed tracks and unconfirmed tracks with observation points.

[0120] The core idea of ​​the NN algorithm is to use the measurement points that fall into the correlation gate established with the prediction point as the center as candidate echoes, and select the measurement points with the closest statistical distance to the prediction point as the echo of the target, and use them to update the prediction point. The GNN algorithm is an extension of the NN algorithm. It is suitable for track association in dense environments. The basic idea is to select the track-measurement association pair with the smallest comprehensive statistical distance as the correct association pair between the target and the target echo. In GNN, a given track is updated by at most one measurement, and one measurement updates at most one track. The process is as follows:

[0121] (a) Calculate the track correlation gate (same as NN algorithm);

[0122] (b) Calculate the statistical distance between the measured and estimated values ​​(same as NN algorithm);

[0123] (c) Eliminate measurement points outside the wave gate;

[0124] (d) calculating the statistical distance matrix among the candidate echoes;

[0125] (e) Optimal allocation of the statistical distance matrix.

[0126] Specifically, let n k Tracks, there are m in this scan k valid observation points. The larger the dimension of the statistical distance matrix established between the track and the observation point, the more time-consuming the allocation algorithm is. Therefore, it is not the best choice to consider allocating all tracks to all observation point tracks. To this end, the idea of ​​clustering can be adopted to form a cluster of multiple tracks with overlapping gates, and finally form one or more clusters. For tracks that do not overlap with the gates of any other track, the NN algorithm is directly used for data association. For multiple tracks belonging to a cluster, the statistical distance d between each track and all measurement points in the partition to which the track belongs is calculated separately. ij (i=1,2,...,n k ; j = 1, 2, ... m k ), construct a statistical distance matrix, and finally perform optimal allocation on the statistical distance matrix (for example, using the Hungarian algorithm to achieve optimal allocation) to obtain each track (i=1,2,...,n k ) is associated with the measurement point i j (i=1,2,...,nk ).

[0127] (6-3) According to the track filtering results, the scoring method is used for track management to achieve ballistic trajectory estimation.

[0128] For example, for free point tracks, each time the gate is connected, 1 point is added, and the minimum score is 1 point (after a free point track is recorded as the track head, 1 point is given), and 3 points are subtracted when a point track is lost. When the free point track scores 2 points, it is moved to the unconfirmed track. For unconfirmed tracks, the gate adds 1 point each time it is connected. If the score of an unconfirmed track is greater than 3 points, it is moved to the confirmed track. After the track is called a confirmed track (the minimum score for a confirmed track is 3 points), the small gate adds 3 points; the large gate adds 2 points, and the system has a maximum score of 8 points. Tracks with less than 1 point will be deleted. If a confirmed track is less than 3 points and not less than 1 point, it will be moved to the unconfirmed track. When the number of tracks is greater than the memory given by the system, the first track is automatically overwritten.

[0129] It is worth mentioning that compared with the ballistic detection system based on the search and tracking phased array radar, the present invention does not require mode switching between the search mode and the tracking mode, and does not require resource scheduling of the tracking beam. Compared with the staring radar descent phase ballistic measurement system with a planar array receiving array, the present invention simultaneously forms multiple receiving beams in azimuth and elevation through digital beamforming technology, has a stronger ability to detect high-speed projectile targets, and has higher azimuth and elevation angle estimation accuracy. Compared with the existing front-end design and signal processing method based on the L-type transceiver array antenna, the present invention uses a left-handed circularly polarized antenna to transmit signals and a right-handed circularly polarized L-type receiving antenna array to receive signals, which effectively improves the transceiver isolation; and, multiple groups of receiving beams are formed in the elevation and azimuth dimensions at the same time, without the need for complex search and tracking beam scheduling, reducing the complexity of the radar system.

[0130] In summary, the projectile landing point detection method based on the L-shaped receiving antenna array provided by the present invention adopts a staring system, and both the transmitting beam and the receiving beam are fixed beams irradiating a fixed area, and no complicated search and tracking beam scheduling is required, which reduces the complexity of the radar system, can meet the real-time requirements in a multi-target scenario, and has lower system development and manufacturing costs. The present invention uses an L-shaped receiving antenna array. Compared with the phased array, the present invention can reduce the number of receiving components and the system scale, while still achieving the same azimuth and elevation angle measurement accuracy, and at the same time forming a digital multi-beam receiving target echo signal, the receiving beam has a wide coverage range, and excellent high-speed target detection performance.

[0131] Based on the same inventive concept, the embodiment of the present invention also provides a projectile landing point detection system based on an L-shaped receiving antenna array. The system uses a linear frequency modulated continuous wave to transmit a fixed wide beam to illuminate a specified airspace, receives the echo signal of the projectile flying target through the L-shaped receiving antenna array, processes the received signal, performs target detection, estimates the distance, speed, azimuth angle, pitch angle and other parameters of the projectile target, obtains the terminal ballistic trajectory of the projectile target through correlation filtering, and further estimates the impact point through extrapolation. See Figure 4 As shown, the projectile landing point detection system based on the L-shaped receiving antenna array provided by the embodiment of the present invention includes: a staring radar and a projectile landing point detection module.

[0132] Among them, the staring radar transmits a wide beam through its transmitting antenna; the width of the wide beam is sufficient to cover the azimuth and elevation dimensions of the detection area; the staring radar receives the echo signal of the wide beam through its L-shaped receiving antenna array; the L-shaped receiving antenna array includes a first uniform linear array arranged in the horizontal direction and a second uniform linear array arranged in the vertical direction.

[0133] Specifically, the transmitting antenna and the L-shaped receiving antenna array are both installed in front of the radar main frame 2. The transmitting antenna beam width is a beam with equal width in the azimuth dimension and the elevation dimension, and the transmitting beam coverage is as large as possible. The L-shaped receiving antenna array is composed of a uniform linear array arranged in the horizontal direction, namely a first uniform linear array (azimuth dimension) and a second uniform linear array arranged in the vertical direction (elevation dimension), which are respectively placed below and on the right side of the radar main frame 2, and the uniform linear array element spacing is half the radar transmission signal wavelength.

[0134] Preferably, the transmitting antenna adopts left-hand circular polarization and the L-shaped receiving antenna array adopts right-hand circular polarization, which can effectively prevent the problem of insufficient isolation when the continuous wave radar receives and transmits co-polarization.

[0135] The projectile landing point detection module is used to implement steps S20 to S60 of the projectile landing point detection method based on the L-shaped receiving antenna array, which will not be repeated here.

[0136] In the embodiment of the present invention, the projectile landing point detection module is a software program module, which can be configured in the staring radar or on a background computer, which is possible.

[0137] In one embodiment, Figure 4The system provided by the embodiment of the present invention also includes: a two-dimensional servo turntable 3 and a tripod 4; wherein the two-dimensional servo turntable 3 is used to realize a rotation of 0 to 360 degrees in the horizontal direction and an adjustment of the pitch angle of -30 degrees to 30 degrees; the radar is installed on the two-dimensional servo turntable 3, and the azimuth and pitch direction of the radar array are changed along with the two-dimensional servo turntable 3; the radar array includes a transmitting antenna and an L-shaped receiving antenna array; the two-dimensional servo turntable 3 is fixed on the tripod 4, for example, it can be fixed on the tripod 4 by hand screws, which is convenient for installation and deployment.

[0138] In one embodiment, the radar array may include: a panel, a transmitting antenna, an L-shaped receiving antenna array, and a transceiver isolation baffle; the transceiver isolation baffle includes a horizontal isolation baffle and a vertical isolation baffle. Here, the transceiver isolation baffle is preferably made of a metal plate, but is not limited thereto.

[0139] The horizontal isolation baffle is located between the transmitting antenna and the first uniform linear array of the L-shaped receiving antenna array, and is arranged close to the transmitting antenna; the vertical isolation baffle is located between the transmitting antenna and the second uniform linear array of the L-shaped receiving antenna array, and is arranged close to the transmitting antenna.

[0140] For example, see Figure 5 ,To ensure the isolation of transmission and reception, the transmitting antenna is placed in the upper left corner away from the receiving antenna, and a metal baffle is installed between the transmitting antenna and the receiving antenna to further improve the ,isolation of transmission and reception.

[0141] In one embodiment, see Figure 6 The hardware components of the staring radar may include: R frequency conversion components, radar control board, frequency synthesis board, inclinometer board, Beidou board and its antenna, wireless network board and its antenna, and processing board.

[0142] Here, the R frequency conversion components include multiple groups (for example, 6), and the R frequency conversion components are connected to the receiving antennas in the L-shaped receiving antenna array by blind plugging for down-conversion processing of the signal. The local oscillator signal required for down-conversion of the R frequency conversion component is provided by the frequency synthesis board. The transmission signal is a Ku-band frequency modulated continuous wave, and a total of two down-conversions are required in this embodiment.

[0143] The radar control board is used to control the staring radar; for example, it is responsible for the control and dispatching of the staring radar, receiving the host computer control instructions and radar working parameters, etc. All peripheral devices are controlled and tested by the radar control board. Peripheral devices include: 2D servo turntable, Beidou board and its antenna, inclinometer board, wireless network board (such as 2.4G wireless network board) and its antenna.

[0144] The frequency synthesizer board is responsible for the generation of clock signals, the generation of wide-beam signal waveforms and up-conversion, and provides the local oscillator signal for the down-conversion of the R frequency conversion component.

[0145] The inclinometer board is used to provide the roll angle and pitch angle information of the array. The inclinometer board can be placed on the back of the radar main frame.

[0146] The Beidou board and its antenna are used to receive and analyze the data received by the Beidou antenna, and provide latitude, longitude, altitude and azimuth information.

[0147] For example, a set of Beidou antennas can include two active antennas, which are respectively installed on the left and right ends of the radar main frame with extended brackets. For easy transportation, the Beidou board is placed on the back of the radar main frame. Here, the Beidou antenna adopts a quick-disassembly design to facilitate the transportation and installation of the radar.

[0148] Wireless network board and antenna are used to realize wireless communication between this system and external devices.

[0149] The processing board is used to implement AD sampling and signal processing; the signal processing mentioned here includes the method steps for implementing the projectile landing point detection module, but is not limited to this.

[0150] Specifically, the processing board is responsible for AD sampling, related processing of digital signals and point trace data processing in this system. It is composed of ADC, FPGA and DSP. The ADC is responsible for sampling the analog signal after down-conversion into a digital signal. There are multiple ADCs in the processing board, and the number of external channels is sufficient to receive the multi-channel analog signal after down-conversion by the R frequency conversion component. The FPGA is used to realize the real-time signal processing and target detection of each multi-beam receiving channel in this system. The DSP realizes the processing of point trace data, such as target point trace correlation filtering and track management. It is also used to realize the ballistic trajectory measurement and landing point detection of the projectile target terminal, and finally reports the results to the display and control host computer.

[0151] In practice, the R frequency conversion component, radar control board, frequency synthesis board and processing board can be installed on the back of the radar main frame.

[0152] The projectile landing point detection system based on the L-shaped receiving antenna array provided by the embodiment of the present invention integrates multiple modules on one board, and uses blind plug-in connection between the receiving antenna and the R frequency conversion component, which reduces the assembly complexity and volume, can meet the needs of high integration and miniaturization, and effectively reduces the R&D cost, making it more suitable for mass production. In this system, AD acquisition, signal processing and data processing are all completed on the processing board, which has a high degree of integration, and no redundant processing is required after the data is sent to the radar host computer, and the performance requirements of the host computer are small. The amount of data sent to the radar display and control host computer after the final data processing is small, which is more suitable for the application scenario where the radar is unattended and the host computer performs remote control.

[0153] It is worth mentioning that compared with traditional landing detection radars, the radar in this system adopts a staring system with simultaneous multiple receiving beams, and the polarization modes of the transmitting and receiving antennas are different. It uses highly integrated hardware boards and all processing work is performed locally. There is no need for resource scheduling in the search and tracking phase, and no need for complex transmit and receive isolation structure design. It has high integration and low manufacturing cost.

[0154] In a specific example, the first uniform linear array is a 24-element uniform linear array arranged horizontally, and the second uniform linear array is a 24-element uniform linear array arranged vertically. The spacing between the receiving antenna uniform linear array elements is half the wavelength of the radar transmission signal, and right-hand circular polarization is used. The radar is set up in the target range at a distance of 200 meters from the expected impact point. The projectile target incident angle is 33°. During the verification experiment, the projectile target is captured at a distance of about 400 meters from the radar. When the radar captures the target, the initial space velocity of the projectile target is about 800m / s. The radar beam is almost parallel to the axis of the projectile movement, that is, the projectile target gradually approaches the radar. The radar data rate is 5ms, and the radar tracks the projectile target for 0.26s. After data processing, the trajectory of the projectile descent is obtained, and the trajectory outside the radar beam is estimated by extrapolation, and the final impact point estimation result is obtained.

[0155] Figure 7 The experimental results for verifying the above-mentioned projectile landing point detection system are shown, in which the actual impact point is used as the coordinate origin, and the ENU coordinate system is used to describe the tracking and impact point estimation results of the projectile target detected by this system. Compared with the actual projectile landing point, the positioning accuracy deviation is 2.52m. The experimental results show that the present invention is effective and accurate in detecting the trajectory and impact point of the projectile target's descent.

[0156] In summary, the present invention adopts a linear frequency modulation continuous wave staring radar system, the transmitting beam and the receiving beam are both fixed beams, no search tracking beam scheduling is required, and the manufacturing cost is low; the L-shaped receiving antenna array is used, and the same azimuth and elevation angle measurement accuracy can be achieved while reducing the number of receiving components and the system scale. Multiple groups of receiving beams are formed simultaneously through DBF, and the receiving beam coverage is wide, and the detection performance of high-speed targets is excellent; the transmitting antenna adopts left-hand circular polarization, and the receiving antenna adopts right-hand circular polarization, which can effectively avoid the problem of insufficient transceiver isolation; the R frequency conversion component integrates the receiving component and the down-conversion function, and is connected to the antenna through a blind plug design, which reduces the wiring harness required for system assembly, and the processing board is highly integrated. Only one board is needed to realize all signal processing and data processing tasks, the system has a high degree of integration, and there is no additional performance requirement for the display and control host computer, and remote control and data reception can be achieved by mounting a wireless network card in the system peripherals. Support remote control, no personnel are required to be stationed, and it has the characteristics of easy installation and deployment, safe operation, and is suitable for projectile target landing point detection radars that are often deployed in shooting ranges and other location scenes.

[0157] It should be noted that the terms "first", "second", etc. are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention.

[0158] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification.

[0159] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other changes to the disclosed embodiments by viewing the drawings and the disclosed content. In the description of the present invention, the term "comprising" does not exclude other components or steps, "one" or "an" does not exclude multiple situations, and "multiple" means two or more, unless otherwise clearly and specifically limited. In addition, certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0160] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the protection scope of the present invention.

Claims

1. A projectile landing point detection method based on an L-shaped receiving antenna array, characterized in that: include: The echo signal is received by using an L-shaped receiving antenna array configured on the staring radar; The L-shaped receiving antenna array includes a first uniform linear array arranged in the horizontal direction and a second uniform linear array arranged in the vertical direction; the echo signal is an echo of a wide beam emitted by the transmitting antenna of the staring radar; the width of the wide beam is sufficient to cover the azimuth and elevation dimensions of the detection area; Simultaneously performing digital beamforming of multiple groups of receiving beams on the echo signals received by the first uniform linear array and the echo signals received by the second uniform linear array, each group of receiving beams including a sum beam and a difference beam; For the sum beams of the first uniform linear array and the second uniform linear array, CFAR detection in the range dimension and the Doppler dimension is performed respectively, and point trace condensation processing is performed on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction; Perform target distance estimation and Doppler velocity estimation according to the first target point trace and the second target point trace respectively, to obtain a first parameter estimation result in the horizontal direction and a second parameter estimation result in the vertical direction; Performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result, and the second parameter estimation result, and performing sum and difference angle measurement according to the target matching result to achieve target angle estimation, so as to obtain a final target detection result; The ballistic trajectory estimation is obtained according to the final target detection result, and the impact point is estimated by extrapolation according to the ballistic trajectory estimation result to realize the projectile landing point detection.

2. The projectile landing point detection method based on the L-shaped receiving antenna array according to claim 1 is characterized in that: The transmitting antenna is a left-hand circularly polarized antenna, and the transmitting antenna uses a Ku-band continuous wave to transmit the wide beam; the antennas in the L-shaped receiving antenna array are all right-hand circularly polarized antennas.

3. The projectile landing point detection method based on the L-shaped receiving antenna array according to claim 1 is characterized in that: For the sum beams of the first uniform linear array and the second uniform linear array, CFAR detection in the range dimension and the Doppler dimension is performed respectively, and point trace condensation processing is performed on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction, including: Performing range-dimensional FFT and moving target detection processing on each group of receiving beams of the first uniform linear array and the second uniform linear array to obtain a range Doppler spectrum of each group of receiving beams; wherein the range Doppler spectrum of each group of receiving beams includes a range Doppler spectrum of a sum beam and a range Doppler spectrum of a difference beam; Performing range-dimension unit average CFAR detection and Doppler-dimension unit average CFAR detection on the range-Doppler spectrum of the sum beam of the first uniform linear array to obtain a range-dimension CFAR result matrix and a Doppler-dimension CFAR result matrix in the horizontal direction, and performing range-dimension unit average CFAR detection and Doppler-dimension unit average CFAR detection on the range-Doppler spectrum of the sum beam of the second uniform linear array to obtain a range-dimension CFAR result matrix and a Doppler-dimension CFAR result matrix in the vertical direction; Performing an AND operation on the distance dimension CFAR result matrix and the Doppler dimension CFAR result matrix in the horizontal direction to obtain the CFAR post-processing result matrix in the horizontal direction, and performing an AND operation on the distance dimension CFAR result matrix and the Doppler dimension CFAR result matrix in the vertical direction to obtain the CFAR post-processing result matrix in the vertical direction; The CFAR post-processing result matrix in the horizontal direction is subjected to point condensation processing to obtain the first target point trace in the horizontal direction, and the CFAR post-processing result matrix in the vertical direction is subjected to point condensation processing to obtain the second target point trace in the vertical direction.

4. The projectile landing point detection method based on the L-shaped receiving antenna array according to claim 3 is characterized in that: The point trace condensation processing is implemented by using the mass center condensation method.

5. The projectile landing point detection method based on the L-shaped receiving antenna array according to claim 1 is characterized in that: Performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result, and the second parameter estimation result includes: Obtaining the target distance and Doppler velocity corresponding to each point in the one target point trace from the first parameter estimation result, and obtaining the target distance and Doppler velocity corresponding to each point in the two target point traces from the second parameter estimation result; A point in the first target point trace and the second target point trace where the target distance and the Doppler velocity are the same is determined as a target.

6. The projectile landing point detection method based on the L-shaped receiving antenna array according to claim 1 is characterized in that: Obtaining a ballistic trajectory estimate according to the final target detection result includes: According to the final target detection result, a logic method is used to extract potential target tracks; According to the extracted potential target tracks, the nearest neighbor NN algorithm or graph nearest neighbor GNN algorithm is used for track association, and the Kalman filter algorithm is used for track filtering; According to the track filtering results, the scoring method is used to manage the track and realize the ballistic trajectory estimation.

7. A projectile landing point detection system based on an L-shaped receiving antenna array, characterized in that: include: Staring radar and projectile impact detection module; The staring radar transmits a wide beam through its transmitting antenna; the width of the wide beam is sufficient to cover the azimuth and elevation dimensions of the detection area; The staring radar receives the wide beam echo signal through its L-shaped receiving antenna array; the L-shaped receiving antenna array includes a first uniform linear array arranged in a horizontal direction and a second uniform linear array arranged in a vertical direction; The projectile landing point detection module is used to implement the following method steps: Simultaneously performing digital beamforming of multiple groups of receiving beams on the echo signals received by the first uniform linear array and the echo signals received by the second uniform linear array, each group of receiving beams including a sum beam and a difference beam; For the sum beams of the first uniform linear array and the second uniform linear array, CFAR detection in the range dimension and the Doppler dimension is performed respectively, and point trace condensation processing is performed on the two-dimensional CFAR detection results to obtain a first target point trace in the horizontal direction and a second target point trace in the vertical direction; Perform target distance estimation and Doppler velocity estimation according to the first target point trace and the second target point trace respectively, to obtain a first parameter estimation result in the horizontal direction and a second parameter estimation result in the vertical direction; Performing target matching according to the first target point trace, the second target point trace, the first parameter estimation result, and the second parameter estimation result, and performing sum and difference angle measurement according to the target matching result to achieve target angle estimation, so as to obtain a final target detection result; The ballistic trajectory estimation is obtained according to the final target detection result, and the impact point is estimated by extrapolation according to the ballistic trajectory estimation result to realize the projectile landing point detection.

8. The projectile landing point detection system based on the L-shaped receiving antenna array according to claim 7 is characterized in that: The system also includes: a two-dimensional servo turntable and a tripod; The two-dimensional servo turntable is used to realize a rotation of 0 to 360° in the horizontal direction and an adjustment of the pitch angle of -30° to 30°; the radar is installed on the two-dimensional servo turntable, and the azimuth and pitch direction of the radar array are changed along with the two-dimensional servo turntable; the radar array includes the transmitting antenna and the L-shaped receiving antenna array; the two-dimensional servo turntable is fixed on the tripod.

9. The projectile landing point detection system based on the L-shaped receiving antenna array according to claim 8 is characterized in that: The radar array includes: a panel, the transmitting antenna, the L-shaped receiving antenna array and a transceiver isolation baffle; the transceiver isolation baffle includes a horizontal isolation baffle and a vertical isolation baffle; The horizontal isolation baffle is located between the transmitting antenna and the first uniform linear array of the L-shaped receiving antenna array, and is arranged close to the transmitting antenna; the vertical isolation baffle is located between the transmitting antenna and the second uniform linear array of the L-shaped receiving antenna array, and is arranged close to the transmitting antenna.

10. The projectile landing point detection system based on the L-shaped receiving antenna array according to claim 7, characterized in that: The hardware components of the staring radar include: R frequency conversion components, lightning control board, frequency synthesis board, inclinometer board, Beidou board and antenna, wireless network board and antenna, and processing board; The R frequency conversion component is connected to the receiving antenna in the L-shaped receiving antenna array by blind plugging, so as to perform down-conversion processing of the signal; The radar control board is used to control the operation of the radar; The frequency synthesizer board is responsible for the generation of the clock signal, the generation of the signal waveform of the wide beam and the up-conversion work, and provides the local oscillator signal for the down-conversion of the R frequency conversion component; The inclinometer board is used to provide the array roll angle and pitch angle information; The Beidou board and its antenna are used to receive and analyze the data received by the Beidou antenna, and provide latitude, longitude, altitude and azimuth information; The wireless network board and antenna are used to realize wireless communication between the system and external devices; The processing board is used to implement AD sampling and signal processing; the signal processing includes the method steps for implementing the projectile landing point detection module.

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