CN-121997555-A - High-mobility low-speed target take-off and landing process parameterization detection method based on passsense signal

CN121997555ACN 121997555 ACN121997555 ACN 121997555ACN-121997555-A

Abstract

The invention discloses a high-mobility low-speed target taking-off and landing process parameterization detection method based on a general sense signal, which comprises the steps of constructing a motion model of an aircraft in a take-off and landing stage to obtain a formula modeling result; the method comprises the steps of obtaining distances and speeds of a plurality of suspicious targets, calculating Doppler frequency modulation information of the targets through a Doppler domain band-pass filter to obtain LVD results to obtain accelerations of the plurality of suspicious targets, calculating backward reflection coefficients of the plurality of suspicious targets based on a radar antenna design principle, obtaining space angles of the plurality of suspicious targets based on array antenna setting of a ventilation system, combining the distances of the plurality of suspicious targets to determine the space positions of the suspicious targets, and screening out the aircraft targets according to the speed, the acceleration, the backward reflection coefficients and the threshold ranges of the space positions of the targets by using a detection module based on physical characteristics of the moving targets. The invention improves the detection capability of low-speed and high-maneuvering moving targets in the environment of low signal-to-noise ratio.

Inventors

XIANG JIXIANG
ZHANG WANRAN
XU JINPENG
CUI YONGJING
LIU XIN
XIA ZHENGHUAN
SUN GUANGCAI

Assignees

西安电子科技大学

Dates

Publication Date: 20260508
Application Date: 20251225

Claims (10)

1. The parameterized detection method for the take-off and landing process of a high-mobility low-speed target based on a passsense signal is characterized by comprising the following steps of: S1, constructing a motion model of an aircraft in a take-off and landing stage to obtain a related formula modeling result; s2, estimating the distance of the moving target based on the formula modeling result to obtain the distances of a plurality of suspicious targets; s3, estimating the speed of the moving target based on the formula modeling result to obtain the speeds of a plurality of suspicious targets; S4, based on the formula modeling result, a band-pass filter is designed in a Doppler domain to obtain an LVD result, doppler frequency modulation information of the target is calculated, acceleration estimation of the moving target is carried out, and accelerations of a plurality of suspicious targets are obtained; S5, calculating the backward reflection coefficients of a plurality of suspicious targets based on a radar antenna design principle; S6, based on the array antenna setting of the general sense system, estimating the space positions of the moving targets to obtain a beam domain space angle measurement result spectrum, obtaining the space angles of a plurality of suspicious targets, and combining the distances of the suspicious targets to determine the space positions of the suspicious targets; S7, utilizing a detection module based on physical characteristics of the moving target, and screening the aircraft targets from the obtained multiple suspicious targets according to threshold ranges preset by the speed, the acceleration, the back reflection coefficient and the space position of the targets.
2. The method according to claim 1, wherein S1 comprises: s11, establishing an instantaneous expression of the distance between the aircraft target and the ventilation system, wherein the instantaneous expression is expressed as: ; wherein, the station height of the sense system is assumed to be , The horizontal distance between the aircraft and the ventilation system is that The aircraft being at speed Acceleration is Carrying out uniform acceleration take-off movement; for the azimuth slow time period, A pitch angle for an aircraft target relative to the motion sensing system; S12, according to the instantaneous expression of the distance between the aircraft target and the passsense system, obtaining an expression of the echo signal received by the passsense system after being reflected by the aircraft target, wherein the expression is expressed as follows: ; In the sense-through system, each pulse of the transmitted waveform is composed of a plurality of complete OFDM symbols, and returns to the sense-through system after being reflected by a target, and the sense-through system is always used ; For the target retroreflectivity coefficient, For the signal transmission bandwidth, Representing distance to fast time; Is to use distance to time To represent the transmission bandwidth of the signal, which is a reference to Is a function of (2); Is the wavelength of the electromagnetic wave of the signal; is an imaginary unit; s13, receiving an expression of the echo signal reflected by the aircraft target through the ventilation system, and obtaining an expression of Doppler frequency of the target, wherein the expression is expressed as follows: ; Wherein, the Representing the Doppler frequency of the target; Is an echo signal Is a phase of the whole; S14, further deriving an expression of the Doppler frequency of the target to obtain an expression of Doppler frequency modulation information of the target, wherein the expression is expressed as follows: ; Wherein, the Doppler frequency modulation information representing the target.
3. The method according to claim 2, wherein S2 comprises: According to the expression of the echo signal received by the passsense system after being reflected by the aircraft target, analyzing the focusing condition of the actual echo and determining the time delay Value according to each time delay determined Obtaining the distance between a focusing point and the passsense system and obtaining the distance between each suspicious object and the passsense system, wherein the calculation formula is as follows: ; Wherein, the After the echo signal is discretized and sampled, each sampling point corresponds to a distance value 。
4. A method according to claim 3, wherein S3 comprises: S31, determining that target speed information is contained in a Doppler domain corresponding to azimuth slow time according to an expression of Doppler frequency of the target, and determining a display form of echo signals in a frequency domain according to a target Doppler effect; wherein the display form of the echo signal in the frequency domain is that the Doppler frequency center is at Stretching to ; S32, according to the display form of the echo signals in the frequency domain and the expression of the Doppler frequency of the target, estimating the interval range of the speed of each suspicious target, and averaging to obtain the speed of the suspicious target, wherein the adopted calculation formula is as follows: ; Wherein, the A number of expanded bins for a suspicious object; to a certain suspicious target The number of the target stretching grids is determined according to the number of sampling points occupied by the suspicious target in particular when the echo signals are analyzed, and the number of the stretching grids of different suspicious targets is different.
5. The method of claim 4, wherein S4 comprises: s41, echo signals are processed And carrying out azimuth slow time dimension representation to obtain: ; Wherein, the Representing the result for the azimuth slow time dimension of the echo signal; On medium molecules In order to be a time-delay conversion factor, For pulse repetition interval time, on denominator The total time observed by the sense-of-general system; Is the number of signals in the echo; representing a suspicious object Target echo energy of the grid; to a certain suspicious target The Doppler frequency corresponding to the lattice broadening; Is a suspicious target Doppler frequency modulation corresponding to the lattice broadening; S42, filtering the echo signal azimuth slow time dimension representation result by using a middle-pass filter and performing inverse Fourier transform in the Doppler domain to obtain a transformed echo signal, wherein the transformed echo signal is expressed as: ; Wherein, the For slow time of orientation after scale transformation Doppler frequency after the scale transformation after FFT transformation; The center frequency point position of the middle-pass filter; is the bandwidth of the middle-pass filter; representing a fourier transform; Representing an inverse fourier transform; representing the total echo energy of the signal passing through the mid-pass filter; Representing the calculated Doppler frequency of the target; Doppler frequency modulation rate information representing a target; S43, performing LVD analysis on the transformed echo signals to obtain an autocorrelation function, wherein the autocorrelation function is expressed as: ; Wherein, the For the scale-conversion factor, use is made of Slow time of azimuth Scaled conversion factor Transforming into azimuth slow time after scale transformation And lag time Is a function of (2); s44, the autocorrelation function is followed And And carrying out Fourier transformation on the two dimensions to complete energy focusing and parameter estimation of the target, and obtaining a corresponding LVD result, wherein the LVD result is expressed as follows: ; Wherein, the Representing the corresponding LVD result, wherein, For slow time of orientation after scale transformation The FFT-transformed doppler frequency, The Doppler frequency is adjusted after the scale conversion; Is an impulse function; S45, according to the obtained LVD result, calculating And the expression of Doppler frequency modulation information of the target, calculating And utilize And calculating the acceleration corresponding to the suspicious object.
6. The method of claim 5, wherein S5 comprises: s51, determining the sense-through system according to the radar principle The power density irradiated by the target is expressed as: ; Wherein, the To sense the power of the system transmitter, In order for the sense-all system to transmit gain, Transmitting the distance between the antenna and the target point for the ventilation system; S52, after being reflected by the target, the echo signal is diffused omnidirectionally, and the target backward reflection coefficient is assumed to be The distance between the target and the receiving antenna is Determining the power density of the target echo at the receiving position of the through sensing system is expressed as: ; s53, when the effective area of the receiving antenna is Determining the echo power received by the through sensing system, which is expressed as: ; s54, determining the gain of the receiving antenna according to the antenna theory Effective area of receiving antenna There is the following relationship between: ; Wherein, the Is the wavelength of the electromagnetic wave of the signal; S55, determining the expression of the echo power received by the through sensing system according to the deduction formulas of S51-S54 as follows: ; S55, analyzing by echo signals Then, according to the distance estimation of the moving object And And according to the parameters as fixed 、、、 Calculating the back reflection coefficient of each suspicious object by using the expression of the echo power received by the ventilation system 。
7. The method of claim 6, wherein S6 comprises: S61, determining a guiding vector caused by the target on each azimuth antenna according to the array antenna setting of the ventilation system, wherein the guiding vector is expressed as: ; Wherein, the azimuth angle of the point target and the through sensing system is Pitch angle of The pitch array interval of the ventilation system is as follows The horizontal array interval is The sense-of-general system is assumed to have in azimuth The antenna is arranged to be connected to a base station, Sharing in common Multiplying the individual columns; S62, assume that the sense-through system is in possession of in the pitch direction The steering vector that the target causes on each pitch antenna is represented by: ; Wherein it is assumed that the sense-through system is in possession of in the pitch direction The antenna is arranged to be connected to a base station, Sharing in common Multiplying the individual columns; S63, integrating the pitching and azimuth angle influences, and expressing each antenna echo as follows: ; Wherein, the Echo vectors formed by echo signals of each antenna in a single time; Subscript for echo data of each antenna Indicating the azimuth direction The antenna is arranged to be connected to a base station, Indicating the pitch direction A root antenna; a steering vector for the spatial area array, wherein: ; Wherein, the , ; S64, utilizing the phase difference of the target in the array antenna caused by the space position information, and calculating the space position of the target through a BS-MUSIC angle measurement algorithm of a beam domain space to obtain a beam domain space angle measurement result spectrum; S65, according to the beam domain space angle measurement result spectrum, space angles of a plurality of suspicious targets are obtained, and the space positions of the suspicious targets are determined by combining the distances of the suspicious targets.
8. The method of claim 7, wherein S64 comprises: S641, performing two-dimensional beam forming based on the beam forming method of the discrete fourier transform, which is a beam forming method with a low operation amount, wherein the formed two-dimensional beam is expressed as: ; Wherein, the Echo data representing each antenna; S642 to Main lobe pointing of each beam , Main lobe pointing of each beam Is defined by the beam former of (a) Is provided with a beam forming matrix of (a), Is that A dimension vector comprising Main lobe pointing of each beam Is provided with a beam formed by a beam former, Is that A dimension vector comprising Main lobe pointing of each beam One dimension corresponding to the generated beam direction and the other dimension corresponding to the beam weights of different antennas, wherein the beam forming matrix is expressed as: ; Wherein, the Is that Is the expression form of (a); ; s643, determining the beam space expression after the beam space transformation is: ; Wherein, the Is a beam domain space signal, and is a distance-to-fast time representation of a two-dimensional beam; S644, calculating a covariance matrix for the beam space expression after the beam space transformation, which is expressed as: ; Wherein, the Is an autocorrelation matrix of the beam space; Is the autocorrelation matrix after space transformation; Is that A corresponding feature vector matrix; a covariance matrix for the beam domain spatial signal; the sum of squares of the row vector means of the beam space information; the space transformation matrix after feature decomposition; s645, decomposing the beam space signal into noise subspaces The expression of the obtained beam domain space angle measurement result spectrum is: ; Wherein, the Is the space transformation vector after feature decomposition.
9. The method according to any one of claims 1-7, wherein S7 comprises: And judging whether the data sets obtained for any suspicious target, including the distance, the speed, the acceleration, the back reflection coefficient and the space position, fall within the corresponding threshold range, and if so, determining that the suspicious target is an aircraft target.
10. A high maneuver low speed target take off and land process parameterized detection device based on a passsense signal, wherein the device comprises, for an interactive scenario of a passsense system and an aircraft target: The motion model construction module is used for constructing a motion model of an aircraft in a take-off and landing stage to obtain a related formula modeling result; The target distance estimation module is used for estimating the distance of the moving target based on the modeling result of the formula to obtain the distances of a plurality of suspicious targets; the target speed estimation module is used for estimating the speed of the moving target based on the formula modeling result to obtain the speeds of a plurality of suspicious targets; The target acceleration estimation module is used for estimating the acceleration of the moving target by designing a band-pass filter in a Doppler domain to obtain an LVD result and calculating Doppler frequency modulation information of the target based on the formula modeling result to obtain the acceleration of a plurality of suspicious targets; the backward reflection coefficient calculation module is used for calculating backward reflection coefficients of a plurality of suspicious targets based on a radar antenna design principle; The space position estimation module is used for estimating the space position of the moving target based on the array antenna setting of the ventilation system, obtaining a beam domain space angle measurement result spectrum, obtaining the space angles of a plurality of suspicious targets, and combining the distances of the suspicious targets to determine the space positions of the suspicious targets; The target screening module is used for screening the aircraft targets from the obtained suspicious targets according to the threshold ranges preset by the detection module based on the physical characteristics of the moving targets according to the speed, the acceleration, the backward reflection coefficient and the spatial position of the targets.

Description

High-mobility low-speed target take-off and landing process parameterization detection method based on passsense signal Technical Field The invention belongs to the technical field of general sense signal processing and moving target detection, and particularly relates to a parameterized detection method for a high-mobility low-speed target lifting process based on a general sense signal. Background The all-weather integrated equipment has the same all-weather working capacity as radar equipment, has higher functional integration level and lower deployment cost compared with the radar equipment, the low-altitude motion target detection based on the ventilation integrated equipment has wide application value in the fields of urban low-altitude traffic supervision and public safety. The core idea of using electromagnetic wave signals to detect moving targets is to distinguish the moving targets by using the characteristic of the targets and the characteristic of clutter in a scene to realize the detection of the moving targets. The conventional Constant False alarm detection algorithm (Constant False-ALARM RATE, CFAR) in the range-Doppler domain only uses the target energy information to detect, and has the defects of low detection rate for low projection speed targets, weak classification recognition capability for high projection acceleration and strong targets and the like when high-mobility low-speed target detection is performed. Therefore, the method has important significance for researching the design of the accurate detection technology for realizing the high-mobility low-speed target. The existing moving target detection method is mostly based on a coherent accumulation and error correction scheme under low signal-to-noise ratio, and the basic thought is that firstly, conventional imaging is carried out on recorded echoes, error sources are presumed through analysis of imaging results, then parameters related to the error sources are estimated, errors are corrected through the estimated parameters, and finally, moving target detection is carried out according to focused images. The wedge-shaped transformation (Keystone Transform, KT) proposed by r.c. dipietr et al in document "R. P. Perry, R. C. Dipietro, R. L. Fante. SAR imaging of moving targets[J]. IEEE Transactions on Aerospace and Electronic Systems, 1999, 35(1): 188-200", achieves the elimination of the problem of linear increase of the relative distance of the target from the radar due to its own speed, i.e. the problem of distance walk. Lixiaolong et al in literature "Li X , Cui G , Yi W ,et al.Fast coherent integration for maneuvering target with high-order range migration via TRT-SKT-LVD[J].IEEE Transactions on Aerospace and Electronic Systems, 2016, 52(6):2803-2814." proposed a coherent accumulation method (TRT-SKT-LVD) based on time-frequency modulation (TRT), wedge-shaped transformation (SKT) and Lv Bianhuan (LVD), performing multi-dimensional search and extraction of parameter space on signals through time-frequency modulation, correcting distance bending caused by acceleration through wedge-shaped transformation, and finally realizing signal coherent accumulation under low signal-to-noise ratio by utilizing Lv transformation. In order to improve the computational complexity, lirion and the like also propose an improved method based on a loop iterative Adjacent Cross Correlation Function (ACCF) algorithm, namely a coherent accumulation algorithm based on the adjacent cross correlation function and LVD (Adjacent Cross Correlation Function and LVD, ACCF-LVD). The algorithm is realized through the fast Fourier transform and the fast inverse Fourier transform, any parameter searching step is not needed, and the calculation efficiency is remarkably improved. On one hand, in the stage of taking off and landing, the aircraft speed is lower, the Doppler frequency shift of echo signals is very small, and in the traditional distance-Doppler two-dimensional spectrum, the echo signals are easily submerged by strong static or slow clutters, so that the conventional detection algorithm is completely ineffective. On the other hand, even if the target signal is not completely submerged, the estimation accuracy (especially acceleration) of the parameter is seriously affected by the presence of strong clutter, the robustness of the existing algorithm in a low signal-to-noise ratio (SNR) environment is insufficient, and the detection performance is obviously deteriorated. These high complexity and low robustness issues together constitute a major obstacle for current advanced algorithms to move from theory to practical application. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a high-mobility low-speed target take-off and landing process parameterization detection method and device based on a passsense signal. The technical problems to be solved by the invention are realized by the following technical sch