A method and system for extremely high frequency echo processing by joint matching of time-frequency domain matrices

Abstract

The invention discloses an extremely high frequency echo processing method and system of time-frequency domain matrix joint matching, firstly, periodically transmitting extremely high frequency linear frequency modulation pulse signal, with a repetition period of T; receiving target echo, constructing multi-frequency domain parallel channel receiving echo data matrix; constructing three-dimensional time-frequency domain joint matching matrix according to target Doppler range and transmission signal bandwidth; performing target echo joint matching filtering based on echo data moment and three-dimensional time-frequency domain joint matching matrix to obtain three-dimensional matrix; performing target plane constant false alarm detection and primary target condensation on the three-dimensional matrix by page, until the primary target condensation of all pages of the data matrix; performing secondary target condensation processing based on time-frequency coupling correspondence on all targets, and estimating target parameters. It is ensured that extremely high frequency radar targets can be effectively detected, the false alarm probability is reduced, and the target parameter estimation accuracy is improved.

Description

Technical Field

[0001] The invention belongs to the field of radar, and relates to an extremely high frequency echo processing method and system for joint matching of time-frequency domain matrices. Background Art

[0002] Conventional radars generally operate at tens of megahertz to tens of gigahertz. With the development of chip and radar technology and the increase in the range and accuracy of target detection, the radar operating frequency has also expanded to the ultra-high frequency band of hundreds of terahertz. Due to the extremely high frequency and short wavelength of the target, conventional radar signal processing methods cannot be used. Therefore, the problem of estimating the distance, speed and other parameters of radar targets in the ultra-high frequency band is an important problem that radars need to solve urgently.

[0003] Conventional radar detection and tracking requires the detection of the three-dimensional coordinates and motion parameters of targets at a long distance. Therefore, the radar first needs to accurately estimate the distance and radial motion speed parameters of the target based on the echo through signal processing methods. In order to improve the detection distance of the target, the radar generally needs to adopt pulse compression technology to increase the transmission power while ensuring a high distance detection estimation accuracy. However, for ultra-high frequency radars, whether using phase-coded pulse compression or linear frequency modulation pulse compression, there will be serious mismatches or even no matching at all due to the extremely high frequency and extremely short wavelength, so pulse compression cannot be achieved, and the target cannot be detected at all, let alone the distance and speed of the target.

[0004] Due to the extremely high frequency band and extremely short wavelength, a very small target movement speed will produce a very large Doppler frequency. The existing moving target parameter estimation method in the extremely high frequency band cannot perform target matching filtering well, and cannot detect the target well, or even cannot detect the target at all, and the target parameter estimation accuracy is not high. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the above-mentioned prior art and provide a time-frequency domain matrix joint matching UHF echo processing method and system to ensure that UHF radar targets can be effectively detected, reduce the false alarm probability and improve the target parameter estimation accuracy.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A time-frequency domain matrix joint matching extremely high frequency echo processing method comprises the following steps:

[0008] Step 1, periodically emitting an extremely high frequency linear frequency modulation pulse signal, with a repetition period of T;

[0009] Step 2, receiving the target echo and constructing a multi-frequency domain parallel channel receiving echo data matrix X;

[0010] Step 3, construct a three-dimensional time-frequency domain joint matching matrix J according to the target Doppler range and the transmission signal bandwidth;

[0011] Step 4, performing joint matching filtering on the target echo based on the echo data matrix X and the three-dimensional time-frequency domain joint matching matrix J to obtain a three-dimensional matrix Z;

[0012] Step 5, performing target plane constant false alarm detection and primary target condensation on the three-dimensional matrix Z page by page, until the primary target condensation is performed on all pages of the data matrix Z;

[0013] Step 6: Perform secondary target aggregation processing on all targets based on the time-frequency coupling correspondence relationship and estimate the target parameters.

[0014] Preferably, in step 1, the extremely high frequency linear frequency modulation pulse signal is:

[0015]

[0016] Among them, e [·] is an exponential function operation with the natural constant e as the base; f0 is the transmitting carrier frequency; is the frequency modulation of the transmitted linear frequency modulation pulse signal; B is the bandwidth of the transmitted linear frequency modulation pulse signal; T p is the effective pulse width of the transmitted linear frequency modulation pulse signal; t is the time.

[0017] Preferably, in step 2, the multi-frequency domain parallel channel receiving echo data matrix is ​​constructed as follows:

[0018] X(:,m,i)=SS(m), where i=1,2,...,N、m=1,2,...,M, N is the number of parallel processing channels, M is the number of pulses received within the coherent processing time, SS(m) is the discrete sampling sequence of the mth pulse received, and the sampling data of each pulse echo are arranged in a column and put into the matrix X in sequence. X(:,m,i) represents the mth column of the i-th page of the received echo data matrix X.

[0019] Preferably, the specific process of step 3 is:

[0020] Sub-step 3.1, first construct N i ,i=1,2,...,N,is the center and the bandwidth is B matching function Where i = 1, 2, ..., N, m = 1, 2, ..., M, t m is the distance dimension sampling time of the mth received pulse within the M coherent pulse processing time, t m =[(m-1)T, (m-1)T+1 / f s , (m-1)T+2 / fs , ..., (m-1)T+(L-1) / f s ] T , [·] T represents the matrix transpose operation, f s is the distance dimension sampling rate, L is the number of distance dimension sampling points; is the frequency modulation of the transmitted linear frequency modulation pulse signal, B is the bandwidth of the transmitted linear frequency modulation pulse signal, T p is the effective pulse width of the transmitted linear frequency modulation pulse signal; H(f i ) is f i A bandpass filter centered at i and having a bandwidth of B, i = 1, 2, ..., N;

[0021] Sub-step 3.2, respectively construct the coherent processing time with frequency f i ,i=1,2,...,N,centered on the i-th group matching function PSref i (;,m)=fft(Sref i (t m )), where i = 1, 2, ..., N, m = 1, 2, ..., M, PSref i (;,m) represents the i-th group matching function PSref i The mth column of , fft(·) represents the fast Fourier transform operation;

[0022] Sub-step 3.3, construct the three-dimensional time-frequency domain joint matching matrix J(:,:,i) = PSref i , where i=1,2,...,N, J(:,:,i) represents the i-th page of the time-frequency domain joint matching matrix J.

[0023] Preferably, the specific process of step 4 is:

[0024] Sub-step 4.1, performing a range-dimensional Fourier transform on the received echo data matrix X to the frequency domain, X_FFT(:,m,i)=fft(X(:,m,i)), wherein i=1,2,...,N, m=1,2,...,M, X(:,m,i) represents the mth column of the i-th page of the echo data matrix X; X_FFT represents the result of the range-dimensional transform of the received echo data matrix X to the frequency domain, X_FFT(:,m,i) represents the mth column of the i-th page of the X_FFT data matrix; fft(X(:,m,i)) represents performing a fast Fourier transform on the mth column of the i-th page of the data matrix X;

[0025] Sub-step 4.2, target echo joint matching filtering;

[0026] Y = ifft(X_FFT.*J);

[0027] Z=fft(Y(l,:,i)), l=1,2,...,L, i=1,2,...,N;

[0028] Where .* represents the dot product of the matrix; Y(l,:,i) represents the lth row of the i-th page of the matrix Y; ifft(·) represents the fast inverse Fourier transform operation.

[0029] Preferably, the specific process of step 5 is:

[0030] Sub-step 5.1, perform planar constant false alarm detection on the i-th page of the data matrix Z, i = 1, 2, ..., N, respectively, and save the horizontal and vertical coordinate sequence numbers and signal amplitude values ​​of the unit where the detected target is located into vector x respectively. zb_i ,y zb_i 、F udu_i middle;

[0031] Sub-step 5.2, performing target condensation on the targets detected on the i-th page of the data matrix Z, i=1, 2, ..., N, respectively;

[0032] First, find the target signal amplitude storage vector F detected on this page udu_i The maximum value in the set is not included in the set, and the sequence number and maximum value of the maximum value are placed in the variable p i 、p maxi Then, the target formed by the target expansion caused by high-resolution sampling is removed from the detected targets, that is, the horizontal coordinate number is located at x zb_i (p i )±Δx zb_i , the vertical coordinate number is located at y zb_i (p i )±Δy zb_i The goal is to udu_i 、x zb_i ,y zb_i Removed from the equation, where Δx zb_i , Δy zb_i The number of horizontal and vertical coordinate units respectively occupied by the target expansion caused by high-resolution sampling of the same target calculated according to the overall parameters is used to complete a target condensation;

[0033] Sub-step 5.3, repeat sub-step 5.2 until the target condensation of all pages of the data matrix Z is completed.

[0034] Preferably, the specific process of step 6 is:

[0035] Sub-step 6.1, secondary target aggregation processing based on time-frequency coupling correspondence;

[0036] Sub-step 6.1.1, first find the target with the strongest energy among all the targets after all the pages of the data matrix Z are condensed once, record the page number of the target into the variable K, and add the horizontal and vertical coordinate number vector x zb_i ,y zb_i Find the horizontal and vertical coordinate numbers of the target and record them in variables K respectively x , K y middle;

[0037] Sub-step 6.1.2, perform secondary condensation processing on the targets found in sub-step 6.1.1, and according to the corresponding relationship between distance and Doppler coupling, remove the detection points of the targets on page i, i = 1, 2, ..., N and i ≠ K, which belong to the same target as the target in sub-step 6.1.1, that is ... y +ΔK yi The target vector F udu_i 、x zb_i ,y zb_i Removed from the list, And i≠K, round(·) means rounding operation; Δf i =f i -f K The difference between the Doppler center frequencies of the i-th page and the K-th page is used to complete the secondary condensation of a target, and the amplitude value of the condensed target is reduced to below the constant false alarm detection threshold, so as to continue the cycle of secondary condensation of other targets;

[0038] Sub-step 6.1.3, repeating sub-step 6.1.1 and sub-step 6.1.2 until the secondary condensation based on the time-frequency coupling correspondence of all targets is completed;

[0039] Sub-step 6.2, target parameter estimation;

[0040] From the horizontal and vertical coordinate sequence vector x of the target after secondary condensation zb_i ,y zb_i , i=1,2,...,N, read out the horizontal and vertical coordinate numbers of each target in turn, and calculate the target parameters;

[0041] w xki =x zb_i (k), k = 1, 2, ..., Q i , i=1,2,...,N;

[0042] w yki =y zb_i (k), k = 1, 2, ..., Q i , i=1,2,...,N;

[0043]

[0044]

[0045] Where λ is the wavelength of the transmitting carrier; C is the speed of light; Q i is the number of targets detected on the i-th page of the data matrix Z after secondary condensation, R0 is the distance value corresponding to the starting point of the distance dimension sampling; PRF is the pulse repetition frequency, V ki is the radial velocity of the kth target on the i-th page estimated by this method; R ki is the distance of the kth target on the i-th page estimated by this method.

[0046] An extremely high frequency echo processing system with time-frequency domain matrix joint matching, comprising:

[0047] An extremely high frequency linear frequency modulation pulse signal transmitting module is used to periodically transmit an extremely high frequency linear frequency modulation pulse signal with a repetition period of T;

[0048] An echo data matrix building module is used to receive target echoes and build a multi-frequency domain parallel channel receiving echo data matrix X;

[0049] A three-dimensional time-frequency domain joint matching matrix construction module is used to construct a three-dimensional time-frequency domain joint matching matrix J according to the target Doppler range and the transmission signal bandwidth;

[0050] A three-dimensional matrix construction module is used for joint matching filtering of target echoes based on the echo data matrix X and the three-dimensional time-frequency domain joint matching matrix J to obtain a three-dimensional matrix Z;

[0051] A primary target condensation module is used to perform target plane constant false alarm detection and primary target condensation on the three-dimensional matrix Z page by page until the primary target condensation is performed on all pages of the data matrix Z;

[0052] The target parameter estimation module is used to perform secondary target aggregation processing on all targets based on the time-frequency coupling correspondence relationship and estimate the target parameters.

[0053] A computer device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the extremely high frequency echo processing method of time-frequency domain matrix joint matching as described in any one of the above items are implemented.

[0054] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the extremely high frequency echo processing method of time-frequency domain matrix joint matching as described in any one of the above items are implemented.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] The present invention constructs a time-frequency domain joint matching matrix and performs time-frequency domain joint matching signal processing, so that the target echo of the linear frequency modulation pulse compression method can be well matched and compressed, avoiding serious mismatching or even completely unable to match, thereby ensuring that the extremely high frequency radar target can be effectively detected, and the target can still be quickly and accurately subjected to two-dimensional joint matching filtering at a large Doppler frequency, effectively ensuring target detection. The present invention further adopts secondary target condensation, which well reduces the false alarm caused by the large Doppler frequency of the target, thereby well reducing the false alarm probability of the entire radar, so that the method has high parameter estimation accuracy and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Figure 1 It is a processing flow chart of an extremely high frequency echo processing method of time-frequency domain matrix joint matching of the present invention;

[0058] Figure 2 It is a time-frequency domain matrix joint matching result diagram of an extremely high frequency echo processing method of a time-frequency domain matrix joint matching of the present invention;

[0059] Figure 3 It is a target primary condensation result diagram after multi-channel time-frequency matching constant false alarm detection of an extremely high frequency echo processing method of a time-frequency domain matrix joint matching of the present invention;

[0060] Figure 4 This is a multi-channel target secondary condensation result diagram of an extremely high frequency echo processing method of a time-frequency domain matrix joint matching of the present invention. DETAILED DESCRIPTION

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments; based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0062] It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to directions in the drawings, and the words "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0063] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0064] like Figure 1 As shown, the extremely high frequency echo processing method of time-frequency domain matrix joint matching according to the present invention comprises the following steps:

[0065] Step 1: The radar system generates an extremely high frequency linear frequency modulation pulse signal and transmits it periodically with a repetition period of T;

[0066]

[0067] Among them, e [·] is an exponential function operation with the natural constant e as the base; f0 is the radar transmitting carrier frequency; is the frequency modulation of the linear frequency modulation pulse signal transmitted by the radar; B is the bandwidth of the linear frequency modulation pulse signal transmitted by the radar; T p is the effective pulse width of the linear frequency modulation pulse signal transmitted by the radar; t is the time.

[0068] Step 2: The radar system receives the target echo and constructs a multi-frequency domain parallel channel radar receiving echo data matrix X;

[0069] The radar system receives the echo signal reflected by the target and converts it into a digital signal through down-conversion and AD sampling. During the coherent processing time, after the radar receives M pulse echo signals, the echo data matrix received by the multi-frequency domain parallel channel radar is constructed as follows:

[0070] X(:,m,i)=SS(m), i=1,2,...,N, m=1,2,...,M;

[0071] Matrix X

[0072]

[0073] Wherein, SS(m) is the discrete sampling sequence of the mth pulse received by the radar; the echo sampling data of each radar pulse are arranged in a column and put into the matrix X in sequence, X(:,m,i) represents the mth column of the i-th page of the echo data matrix X received by the radar; X(:,:,i) represents the i-th page of the radar received echo data matrix X used for time-frequency domain joint matching processing; N is the number of parallel channels for joint matching processing, and the number of sampling points in the distance dimension is L.

[0074] Step 3, construct a three-dimensional time-frequency domain joint matching matrix J according to the target Doppler range and the transmission signal bandwidth;

[0075] Because the radar frequency is extremely high and the wavelength is extremely short, even if the target has a very small movement speed, a large Doppler will be generated, and the Doppler frequency is much larger than the bandwidth B of the transmitted linear frequency modulation signal; because the radar detects and tracks non-cooperative enemy targets, there is no prior data on the target motion parameters, which results in the radar receiver needing to receive signals in a large frequency range to ensure that the target echo signal is effectively received. The bandwidth of the digital signal after down-conversion and AD sampling can reach several gigahertz. It is obviously difficult to directly perform linear frequency modulation pulse matching compression on the echo signal with a bandwidth of several gigahertz. To solve this problem, the present invention divides the received signal into frequency bands and processes it in parallel according to the target Doppler range and the bandwidth of the transmitted signal to ensure that the target echo signal is effectively received and processed.

[0076] Sub-step 3.1, first construct N i , i = 1, 2, ..., N, with a pulse pressure matching function of center and bandwidth B:

[0077]

[0078] Among them, t m =[(m-1)T, (m-1)T+1 / f s , (m-1)T+2 / f s , ..., (m-1)T+(L-1) / f s ] T is the distance dimension sampling time, [·] T is the matrix transpose operation; M is the number of pulses received by the radar during the coherent processing time; L is the number of sampling points in the range dimension; f s is the distance dimension sampling rate; T is the pulse repetition period; H(f i ) is f i ,i=1,2,...,N,is a bandpass filter with center and bandwidth B.

[0079] Sub-step 3.2, respectively construct the coherent processing time with frequency f i ,i=1,2,...,N,centered in the i-th group matching function:

[0080] PSref i (;,m)=fft(Sref i (t m )), i=1,2,...,N, m=1,2,...,M;

[0081] Among them, PSrefi (;,m) represents the i-th group matching function PSref i The mth column of ; fft(·) represents the fast Fourier transform operation.

[0082] Sub-step 3.3, constructing the time-frequency domain joint matching matrix J;

[0083] J(:,:,i)=PSref i , i=1,2,...,N;

[0084] Matrix J

[0085]

[0086] Among them, J is the time-frequency domain joint matching matrix, and J(:,:,i) represents the i-th page of the three-dimensional time-frequency domain joint matching matrix J.

[0087] Step 4: Joint matching filtering of target echoes based on the three-dimensional time-frequency domain joint matching matrix.

[0088] In order to increase the signal-to-noise ratio of weak target echo signals submerged in noise and improve the probability of target detection, the present invention performs time-frequency domain joint matching processing on the echo data matrix X received by the radar.

[0089] Sub-step 4.1, performing range-dimensional Fourier transform on the radar received echo data matrix X to the frequency domain;

[0090] X_FFT(:,m,i)=fft(X(:,m,i)), i=1,2,...,N, m=1,2,...,M;

[0091] Among them, X(:,m,i) represents the mth column of the i-th page of the echo data matrix X; X_FFT represents the result of transforming the radar received echo data matrix X from the range dimension to the frequency domain, X_FFT(:,m,i) represents the mth column of the i-th page of the X_FFT matrix; fft(X(:,m,i)) represents the fast Fourier transform of the mth column of the i-th page of the matrix X.

[0092] Sub-step 4.2, target echo joint matching filtering;

[0093] Y = ifft(X_FFT.*J);

[0094] Z=fft(Y(l,:,i)), l=1,2,...,L, i=1,2,...,N;

[0095] Where .* represents the dot product of the matrix; Y(l,:,i) represents the lth row of the i-th page of the matrix Y; ifft(·) represents the fast inverse Fourier transform operation.

[0096] Step 5: Perform target plane constant false alarm detection and primary target aggregation on the matrix Z page by page.

[0097] Sub-step 5.1, perform planar constant false alarm detection on the i-th page of the data matrix Z, i = 1, 2, ..., N, respectively, and save the horizontal and vertical coordinate sequence numbers and signal amplitude values ​​of the unit where the detected target is located into vector x respectively. zb_i ,y zb_i 、F udu_i middle.

[0098] In sub-step 5.2, target condensation is performed on the targets detected on the i-th page of the data matrix Z, i=1, 2, ..., N, respectively.

[0099] First, find the target signal amplitude storage vector F detected on this page udu_i The maximum value in the set is not included in the set, and the sequence number and maximum value of the maximum value are placed in the variable p i 、p maxi middle;

[0100] (p i ,p maxi )=max(F udu_i ), i = 1, 2, ..., N;

[0101] Among them, max(·) represents the maximum value operation, finding the vector F udu_i The maximum value of the maximum value, and put the maximum value number and the maximum value into the variable p i 、p maxi middle.

[0102] Then, the targets formed by target expansion due to high-resolution sampling are removed from the detected targets, that is, the detected targets with the horizontal coordinate number at x are removed. zb_i (p i )±Δx zb_i , the vertical coordinate number is located at y zb_i (p i )±Δy zb_i The goal is to udu_i 、x zb_i ,y zb_i Removed from the equation, where Δx zb_i , Δy zb_i The number of horizontal and vertical coordinate units respectively occupied by the target expansion caused by high-resolution sampling of the same target calculated based on the overall parameters of the radar is used to complete a target condensation.

[0103] Sub-step 5.3, repeat sub-step 5.2 until the target condensation of all pages of the data matrix Z is completed.

[0104] Step 6: secondary target aggregation processing and target parameter estimation based on the time-frequency coupling correspondence.

[0105] In order to accurately estimate the target parameters, the present invention adopts secondary target aggregation to further reduce the false alarm probability and improve the parameter estimation accuracy.

[0106] Sub-step 6.1, secondary target aggregation processing based on time-frequency coupling correspondence;

[0107] Different pages of the data matrix Z correspond to different signal frequency bands. Because the radar frequency is extremely high and the wavelength is extremely short, a very small target movement speed will produce a large Doppler, and a large Doppler will cause a deviation between the distance measurement value and the true value of the same target. Therefore, secondary condensation of the detection points belonging to the same target in different pages of the data matrix Z can further reduce the false alarm probability and improve the parameter measurement accuracy.

[0108] Sub-step 6.1.1, first find the target with the strongest energy among all the targets after all the pages of the data matrix Z are condensed once, record the page number of the target into the variable K, and add the horizontal and vertical coordinate number vector x zb_i ,y zb_i Find the horizontal and vertical coordinate numbers of the target and record them in variables K respectively x , K y middle;

[0109] Sub-step 6.1.2, performing secondary agglomeration processing on the target found in sub-step 6.1.1;

[0110]

[0111] Among them, round(·) represents rounding operation, Δf i =f i -f K is the difference between the Doppler center frequencies of the i-th page and the K-th page.

[0112] According to the correspondence between distance and Doppler coupling, the detection points of the targets after the first condensation on the i-th page that belong to the same target as the target in sub-step 6.1.1 are removed, that is, the detection points of the targets after the first condensation on the i-th page whose ordinate numbers are located at K y +ΔK yi The target vector F udu_i 、x zb_i ,y zb_i The target is eliminated from the target, the secondary condensation of a target is completed, and the target amplitude value of this condensation is reduced to below the constant false alarm detection threshold, so as to continue the cycle of secondary condensation of other targets.

[0113] Sub-step 6.1.3, repeat sub-step 6.1.1 and sub-step 6.1.2 until the secondary condensation based on the time-frequency coupling correspondence of all targets is completed.

[0114] Sub-step 6.2, target parameter estimation;

[0115] From the horizontal and vertical coordinate sequence vector x of the target after secondary condensation zb_i ,y zb_i , i=1,2,...,N, read out the horizontal and vertical coordinate numbers of each target in turn, and calculate the target parameters.

[0116] w xki =x zb_i (k), k = 1, 2, ..., Q i , i=1,2,...,N;

[0117] w yki =y zb_i (k), k = 1, 2, ..., Q i , i=1,2,...,N;

[0118]

[0119]

[0120] Where λ is the wavelength of the radar carrier; C is the speed of light; Q i is the number of targets detected on the i-th page of the data matrix Z after secondary condensation; R0 is the distance value corresponding to the starting point of the distance dimension sampling; PRF is the pulse repetition frequency, V ki is the radial velocity of the kth target on the i-th page estimated by this method; R ki is the distance of the kth target on the i-th page estimated by this method.

[0121] The effect of this embodiment is further illustrated by the following simulation experiment.

[0122] (1) Simulation conditions:

[0123] An extremely high frequency radar measures the distance and radial velocity parameters of a vehicle which is 9.8 km away from the radar and is moving towards the radar at a constant speed of 20 m / s, using an extremely high frequency echo processing method of the present invention with combined matching of time-frequency domain matrices.

[0124] (2) Simulation content and results:

[0125] Figure 2This is the time-frequency domain matrix joint matching result of the extremely high frequency echo processing method of the present invention. It can be seen that the method of the present invention enables the target echo of the linear frequency modulation pulse compression method to be better matched and compressed, avoiding serious mismatches or even complete inability to match, thereby ensuring that the extremely high frequency radar target can be effectively detected.

[0126] Figure 3 It is a target primary condensation result after constant false alarm detection of an extremely high frequency echo processing method of a time-frequency domain matrix joint matching of the present invention.

[0127] Figure 4 It is a multi-channel target secondary condensation result of an extremely high frequency echo processing method of a time-frequency domain matrix joint matching of the present invention.

[0128] The following are device embodiments of the present invention, which can be used to perform method embodiments of the present invention. For details not disclosed in the device embodiments, please refer to the method embodiments of the present invention.

[0129] In another embodiment of the present invention, a very high frequency echo processing system with time-frequency domain matrix joint matching is provided. The very high frequency echo processing system with time-frequency domain matrix joint matching can be used to implement the above-mentioned very high frequency echo processing method with time-frequency domain matrix joint matching. Specifically, the very high frequency echo processing system with time-frequency domain matrix joint matching includes an extremely high frequency linear frequency modulation pulse signal transmitting module, an echo data matrix construction module, a three-dimensional time-frequency domain joint matching matrix construction module, a three-dimensional matrix construction module, a primary target condensation module and a target parameter estimation module.

[0130] Among them, the extremely high frequency linear frequency modulation pulse signal transmission module is used to periodically transmit extremely high frequency linear frequency modulation pulse signals with a repetition period of T; the echo data matrix construction module is used to receive target echoes and construct a multi-frequency domain parallel channel receiving echo data matrix X; the three-dimensional time-frequency domain joint matching matrix construction module is used to construct a three-dimensional time-frequency domain joint matching matrix J according to the target Doppler range and the transmission signal bandwidth; the three-dimensional matrix construction module is used for target echo joint matching filtering based on the echo data matrix X and the three-dimensional time-frequency domain joint matching matrix J to obtain a three-dimensional matrix Z; the primary target condensation module is used to perform target plane constant false alarm detection and primary target condensation on the three-dimensional matrix Z page by page until the primary target condensation of all pages of the data matrix Z; the target parameter estimation module is used to perform secondary target condensation processing on all targets based on the time-frequency coupling correspondence relationship, and estimate the target parameters.

[0131] In another embodiment of the present invention, a terminal device is provided, the terminal device includes a processor and a memory, the memory is used to store a computer program, the computer program includes program instructions, and the processor is used to execute the program instructions stored in the computer storage medium. The processor may be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application specific integrated circuits (ASIC), field-programmable gate arrays (FPGAs), or other processors. GateArray, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc., which are the computing core and control core of the terminal, which are suitable for implementing one or more instructions, and are specifically suitable for loading and executing one or more instructions to implement the corresponding method flow or corresponding functions; the processor described in the embodiment of the present invention can be used for the operation of the extremely high frequency echo processing method of time-frequency domain matrix joint matching, including: step 1, periodically transmitting extremely high frequency linear frequency modulation pulse signals with a repetition period of T; step 2, receiving target echoes, and constructing a multi-frequency domain parallel channel receiving echo data matrix X; step 3, constructing a three-dimensional time-frequency domain joint matching matrix J according to the target Doppler range and the transmission signal bandwidth; step 4, based on the target echo joint matching filtering of the echo data matrix X and the three-dimensional time-frequency domain joint matching matrix J, a three-dimensional matrix Z is obtained; step 5, performing target plane constant false alarm detection and primary target condensation on the three-dimensional matrix Z by page, until the primary target condensation of all pages of the data matrix Z; step 6, performing secondary target condensation processing on all targets based on the time-frequency coupling correspondence relationship, and estimating the target parameters.

[0132] In another embodiment, the present invention further provides a computer-readable storage medium (Memory), which is a memory device in a terminal device for storing programs and data. It is understandable that the computer-readable storage medium here can include both the built-in storage medium in the terminal device and the extended storage medium supported by the terminal device. The computer-readable storage medium provides a storage space, which stores the operating system of the terminal. In addition, one or more instructions suitable for being loaded and executed by the processor are also stored in the storage space, and these instructions can be one or more computer programs (including program codes). It should be noted that the computer-readable storage medium here can be a high-speed RAM memory or a non-volatile memory, such as at least one disk memory.

[0133] One or more instructions stored in a computer-readable storage medium can be loaded and executed by a processor to implement the corresponding steps of the extremely high frequency echo processing method for joint matching of time-frequency domain matrices in the above embodiment; one or more instructions in the computer-readable storage medium are loaded by the processor and the following steps are executed: step 1, periodically transmitting an extremely high frequency linear frequency modulation pulse signal with a repetition period of T; step 2, receiving target echoes and constructing a multi-frequency domain parallel channel receiving echo data matrix X; step 3, constructing a three-dimensional time-frequency domain joint matching matrix J according to the target Doppler range and the transmission signal bandwidth; step 4, performing joint matching filtering of target echoes based on the echo data matrix X and the three-dimensional time-frequency domain joint matching matrix J to obtain a three-dimensional matrix Z; step 5, performing target plane constant false alarm detection and primary target condensation on the three-dimensional matrix Z page by page until the primary target condensation of all pages of the data matrix Z; step 6, performing secondary target condensation processing on all targets based on the time-frequency coupling correspondence relationship, and estimating the target parameters.

[0134] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0135] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0136] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0137] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process in the computer or other programmable device. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0138] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0139] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. A method for processing extremely high frequency echoes by joint matching of time-frequency domain matrices, characterized in that: The following steps are involved: Step 1: Periodically emit a very high frequency linear frequency modulation pulse signal with a repetition period of T ; Step 2: Receive the target echo and construct a multi-frequency domain parallel channel receiving echo data matrix ; Step 3: Construct a three-dimensional time-frequency domain joint matching matrix based on the target Doppler range and the transmitted signal bandwidth ; Step 4, based on the echo data matrix and the three-dimensional time-frequency domain joint matching matrix The target echo is combined with matched filtering to obtain a three-dimensional matrix Z ; Step 5: For the three-dimensional matrix Z Perform target plane constant false alarm detection and target aggregation page by page until the data matrix Z A goal cohesion for all pages; Step 6: Perform secondary target aggregation processing on all targets based on the time-frequency coupling correspondence relationship and estimate the target parameters.

2. The extremely high frequency echo processing method of time-frequency domain matrix joint matching according to claim 1 is characterized in that: In step 1, the extremely high frequency linear frequency modulation pulse signal is: in, The natural constant e Exponential function operation with base ; is the transmitting carrier frequency, The frequency modulation rate for transmitting the linear frequency modulation pulse signal; B is the bandwidth of the transmitted linear frequency modulated pulse signal; is the effective pulse width of the transmitted linear frequency modulation pulse signal; For time.

3. The extremely high frequency echo processing method of time-frequency domain matrix joint matching according to claim 1 is characterized in that: In step 2, the multi-frequency domain parallel channel receiving echo data matrix is ​​constructed as: ,in, , , N is the number of parallel processing channels, M is the number of pulses received during the coherent processing time, To receive the m The discrete sampling sequence of pulses is arranged into a column and placed into the matrix in sequence. X middle, Represents the received echo data matrix X No. i Page No. m List.

4. The method for processing extremely high frequency echoes by combining matrix matching in time and frequency domains according to claim 1, characterized in that: The specific process of step 3 is: Sub-step 3.1, first build N Frequency , , is the center and the bandwidth is B The matching function ,in, , ; for M The first m The distance dimension sampling time of each received pulse, , Represents the matrix transpose operation; is the distance dimension sampling rate, is the number of sampling points in the distance dimension; The frequency modulation of the linear frequency modulation pulse signal is transmitted. B is the bandwidth of the transmitted linear frequency modulated pulse signal, is the effective pulse width of the transmitted linear frequency modulation pulse signal; So , , is the center and the bandwidth is B Bandpass filter; Sub-step 3.2, respectively construct the coherent processing time with frequency , , the center i Group matching function ,in, , , Indicates i Group matching function No. m List, represents the fast Fourier transform operation; Sub-step 3.3: Constructing a three-dimensional time-frequency domain joint matching matrix ,in, , represents the joint matching matrix in the time-frequency domain No. i Page.

5. The extremely high frequency echo processing method of time-frequency domain matrix joint matching according to claim 1, characterized in that: The specific process of step 4 is: Sub-step 4.1: docking the received wave data matrix X Perform a distance-dimensional Fourier transform to the frequency domain, ,in, , ; Represents the echo data matrix X No. i Page No. m List; Represents the received echo data matrix X The result of transforming the distance dimension to the frequency domain is, express The data matrix i Page No. m List; Represents the data matrix X No. i Page No. m Fast Fourier transform of the columns; Sub-step 4.2, target echo joint matching filtering; ； ， 、 ； in, Represents the dot product of matrices; Representation Matrix Y No. i Page No. l OK; Represents the fast inverse Fourier transform operation.

6. The extremely high frequency echo processing method of time-frequency domain matrix joint matching according to claim 1, characterized in that: The specific process of step 5 is: Sub-step 5.1, respectively, the data matrix Z No. i Page, , perform plane constant false alarm detection, and save the horizontal and vertical coordinate numbers of the unit where the detected target is located and the signal amplitude values ​​into vectors x zb_i , y zb_i , F udu_i middle; Sub-step 5.2, respectively, the data matrix Z No. i Page, ,The detected target performs a target condensation; First, find the target signal amplitude storage vector detected on this page The maximum value in the , the target that has completed a condensation does not participate, and the sequence number of the maximum value and the maximum value are placed in the variable p i 、p maxi Then, the target formed by the target expansion caused by high-resolution sampling is removed from the detected targets, that is, the horizontal coordinate number is located at , the vertical axis number is located at The goal from F udu_i , x zb_i , y zb_i Removed from the list, , The number of horizontal and vertical coordinate units respectively occupied by the target expansion caused by high-resolution sampling of the same target calculated according to the overall parameters is used to complete a target condensation; Sub-step 5.3, repeat sub-step 5.2 until the data matrix is ​​complete. Z A single goal for all pages.

7. The extremely high frequency echo processing method of time-frequency domain matrix joint matching according to claim 1, characterized in that: The specific process of step 6 is: Sub-step 6.1, secondary target aggregation processing based on time-frequency coupling correspondence; Sub-step 6.1.1, first find the data matrix Z The target with the strongest energy among all the targets after all pages are condensed at once is recorded in the variable K and from the horizontal and vertical coordinate vector x zb_i , y zb_i Find the horizontal and vertical coordinate numbers of the target and record them in variables respectively K x , K y middle; Sub-step 6.1.2, perform secondary condensation processing on the targets found in sub-step 6.1.1, and respectively condense the first i Page, and , the detection points that belong to the same target as the target in sub-step 6.1.1 are removed from the target after the first condensation. i Page, and , the ordinate sequence number of all targets after one condensation is located at The target from the vector F udu_i , x zb_i , y zb_i Removed from the list, , and , Indicates rounding operation; For the i Page and K The difference between the Doppler center frequencies of the two pages is used to complete the secondary coagulation of a target, and the amplitude value of the coagulated target is reduced to below the constant false alarm detection threshold, so as to continue the cycle of secondary coagulation of other targets; Sub-step 6.1.3, repeating sub-step 6.1.1 and sub-step 6.1.2 until the secondary condensation based on the time-frequency coupling correspondence of all targets is completed; Sub-step 6.2, target parameter estimation; From the horizontal and vertical coordinate sequence vector of the target after secondary condensation x zb_i , y zb_i , , read out the horizontal and vertical coordinate numbers of each target in turn, and calculate the target parameters; ， 、 ； ， 、 ； ， 、 ； ， 、 ； in, is the transmitting carrier wavelength; is the speed of light; is the data matrix after secondary condensation Z No. i The number of targets detected by the page, is the distance value corresponding to the sampling starting point of the distance dimension; PRF is the pulse repetition frequency, ; The estimated value obtained by this method is i Page k The radial velocity of the target; The estimated value obtained by this method is i Page k The distance to the target, M is the number of pulses received by the radar during the coherent processing time.

8. An extremely high frequency echo processing system with time-frequency domain matrix joint matching, characterized in that: include: The extremely high frequency linear frequency modulation pulse signal transmitting module is used to periodically transmit extremely high frequency linear frequency modulation pulse signals with a repetition period of T ; Echo data matrix building module, used to receive target echoes and build multi-frequency domain parallel channel receiving echo data matrix ; A three-dimensional time-frequency domain joint matching matrix construction module is used to construct a three-dimensional time-frequency domain joint matching matrix based on the target Doppler range and the transmitted signal bandwidth ; 3D matrix building module for echo data matrix and the three-dimensional time-frequency domain joint matching matrix The target echo is combined with matched filtering to obtain a three-dimensional matrix Z ; A target aggregation module for three-dimensional matrix Z Perform target plane constant false alarm detection and target aggregation page by page until the data matrix Z A goal cohesion for all pages; The target parameter estimation module is used to perform secondary target aggregation processing on all targets based on the time-frequency coupling correspondence relationship and estimate the target parameters.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the extremely high frequency echo processing method of time-frequency domain matrix joint matching as described in any one of claims 1 to 7 are implemented.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the extremely high frequency echo processing method of time-frequency domain matrix joint matching as claimed in any one of claims 1 to 7 are implemented.

Images