Portable Omnidirectional True Aperture Ground-Based Radar and Its Control Method

Abstract

The present application relates to a portable omnidirectional true-aperture ground-based radar and its control method. The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The radar includes: a signal transceiver system equipped with an antenna for transmitting and receiving radar signals; a turntable system for driving the signal transceiver system to rotate to transmit and receive radar signals at different angles; a signal processing system including a first correction module and a second correction module. The first correction module is used to correct the deformation offset caused by the installation errors of the signal transceiver system and the turntable system and the repeated positioning error of the turntable system. The second correction module is used to correct the self-coupling signal in the radar signal; a control system is respectively connected to the signal transceiver system, the turntable system, and the signal processing system to control the operation of the signal transceiver system, the turntable system, and the signal processing system.

Description

Technical Field

[0001] This application relates to the field of radar technology, and particularly to a portable omnidirectional true-aperture ground-based radar and its control method. Background Art

[0002] During the actual operation of the radar, the system needs to use the collected data for scene deformation inversion. The scene deformation inversion uses differential interferometry technology, that is, multi-track data is required to perform phase difference. Due to the certain repeat positioning error of the actual operating turntable system, and at the same time, there is a certain installation error when the antenna is installed on the turntable system, which makes the antenna have a certain non-ideal rotation radius when rotating. Combining the above repeat positioning error, when performing phase difference according to the transmitted and received signals, the interference phase will shift, seriously affecting the displacement amount of using differential interferometry technology to invert scene deformation, affecting the deformation inversion accuracy of the radar, and further affecting the radar monitoring accuracy.

[0003] In addition, when using a true-aperture antenna to transmit and receive signals, due to the high gain of the true-aperture antenna and the high signal-to-noise ratio of the received signal, high-precision true deformation inversion can be achieved; however, due to the long length and large volume of the antenna, in order to avoid increasing the overall installation volume, the distance between antennas cannot be too large. In this way, there will be a certain coupling signal between adjacent antennas that submerges the target in the real scene, resulting in poor deformation inversion accuracy. Therefore, it is necessary to eliminate the influence of the self-coupling signal brought by the real-aperture antenna. Summary of the Invention

[0004] The purpose of the embodiments of this application is to provide a portable omnidirectional true-aperture ground-based radar and its control method to solve the technical problems that the existing portable omnidirectional true-aperture ground-based radar affects the radar monitoring accuracy due to installation errors, signal coupling, etc.

[0005] On the one hand, the embodiments of this application provide a portable omnidirectional true-aperture ground-based radar. The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The portable omnidirectional true-aperture ground-based radar includes:

[0006] A signal transceiver system equipped with an antenna for transmitting and receiving radar signals;

[0007] A turntable system for driving the signal transceiver system to rotate to transmit and receive radar signals at different angles;

[0008] A signal processing system including a first correction module and a second correction module. The first correction module is used to correct the deformation offset caused by the installation errors of the signal transceiver system and the turntable system and the repeat positioning error of the turntable system, and the second correction module is used to correct the self-coupling signal in the radar signal;

[0009] A control system, which is respectively connected to the signal transceiver system, the turntable system, and the signal processing system to control the operations of the signal transceiver system, the turntable system, and the signal processing system.

[0010] In some embodiments, the signal transceiver system controls the antenna to transmit and receive signals through a frequency-modulated continuous wave working system, and the transmitted signal is a frequency-modulated continuous wave signal composed of a plurality of sub-pulse signals.

[0011] In some embodiments, the first correction module includes:

[0012] An inverse Fourier transform unit, which is used to perform an inverse Fourier transform on the signal in the range direction;

[0013] A first calculation unit, which is used to calculate the stability of the signal according to the signal transformed by the inverse Fourier transform unit;

[0014] A screening unit, which is used to screen signals that meet preset conditions according to the stability of the signal;

[0015] A deformation offset determination unit, which is used to calculate the deformation offset caused by the non-ideal radius and the repeated positioning error of the turntable system;

[0016] A correction unit, which is used to correct the deformation offset.

[0017] In some embodiments, the screening unit screening signals that meet preset conditions according to the stability of the signal includes:

[0018] Keeping the stability coefficient greater than the preset threshold TT 阈值 unchanged to screen and retain the target position with a high stability coefficient SS 稳定系数mn ;

[0019] Setting the stability coefficient less than the preset threshold TT 阈值 to 0.

[0020] In some embodiments, the deformation offset determination unit is used to:

[0021] Accumulating the complex signals after range compression of multiple sub-pulse signals of the same transmitted signal to form the signal of a single sub-pulse after accumulation;

[0022] Calculating the one-dimensional matrix correlation quantity;

[0023] Constructing a search movement compensation factor;

[0024] Compensating the signal according to the constructed movement compensation factor;

[0025] Obtaining and storing the correlation quantity.

[0026] In some embodiments, the second correction module includes:

[0027] A first acquisition unit, configured to acquire the angular data of the two-dimensional matrix in each page with a stability exceeding a threshold, and arrange the angular data in sequence to obtain a data matrix D new ;

[0028] A second calculation unit, configured to disorderly arrange the data matrix D new and calculate the covariance matrix;

[0029] A second acquisition unit, configured to obtain the DC component of each column matrix according to Fourier transform, and record the distance value of the corresponding column of the matrix;

[0030] A fitting unit, configured to fit and obtain the one-dimensional range of the self-coupling signal;

[0031] An elimination unit, configured to remove the fitted self-coupling signal from the overall signal.

[0032] In some embodiments, the signal processing system further includes a preprocessing module, and the preprocessing module includes:

[0033] A redundant signal processing unit, configured to process redundant signals in the acquired signals;

[0034] A segmentation unit, configured to segment each sub-pulse in each angular direction.

[0035] In some embodiments, the signal processing system further includes an imaging stitching module, and the imaging stitching module includes:

[0036] A range image stitching unit, configured to accumulate the data processed by the preprocessing module in the form of row vectors along the page direction axis, and at the same time arrange the respective angular data recorded by the control system in ascending order, and form a two-dimensional matrix with the accumulated data to obtain the stitched two-dimensional radar image data;

[0037] A coordinate system conversion unit, configured to perform coordinate system conversion on the stitched two-dimensional radar image data;

[0038] An output unit, configured to output the imaging result after coordinate system conversion, and store the data of the imaging result in a fixed format.

[0039] In some embodiments, the antenna is a dual real-aperture antenna, including a transmitting antenna and a receiving antenna. The outer contour of the dual real-aperture antenna is rectangular, and the horizontal side length is greater than the pitch side length.

[0040] On the other hand, the embodiment of the present application also provides a control method for a portable omnidirectional true-aperture ground-based radar. The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The portable omnidirectional true-aperture ground-based radar includes a signal transceiver system, a turntable system, and a signal processing system. The control method includes:

[0041] Controlling the antenna installed in the signal transceiver system to transmit and receive radar signals;

[0042] Controlling the turntable system to rotate to drive the signal transceiver system to rotate so as to transmit and receive radar signals at different angles;

[0043] Controlling the first correction module and the second correction module of the signal processing system to correct the radar signals. The first correction module is used to correct the deformation offset caused by the installation error of the signal transceiver system and the turntable system and the repeated positioning error of the turntable system. The second correction module is used to correct the self-coupling signals in the radar signals

[0044] The portable omnidirectional true-aperture ground-based radar and its control method provided by the embodiment of the present application can improve the deformation inversion accuracy of the radar and thus improve the monitoring accuracy of the radar by setting a first correction module to correct the non-ideal radius caused by the installation error between the antenna and the turntable system and the deformation offset caused by the repeated positioning error of the turntable system, and setting a second correction module to correct the self-coupling signals generated due to the close spacing of the true-aperture antennas. In addition, the present application uses true-aperture antennas, which are convenient for radar deployment, easy to carry, have a wide range of applications, and can achieve omnidirectional monitoring in the horizontal and pitch directions. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 is a schematic structural diagram of the portable omnidirectional true-aperture ground-based radar according to the embodiment of the present application;

[0046] Figure 2 is a schematic structural diagram of the preprocessing module according to the embodiment of the present application;

[0047] Figure 3 is a schematic structural diagram of the first correction module according to the embodiment of the present application;

[0048] Figure 4 is a schematic structural diagram of the second correction module according to the embodiment of the present application;

[0049] Figure 5 is a schematic structural diagram of the imaging stitching module according to the embodiment of the present application;

[0050] Figure 6 is a flowchart of the control method for the portable omnidirectional true-aperture ground-based radar according to the embodiment of the present application.

[0051] Reference numerals:

[0052] 1 - Signal transceiver system, 11 - Antenna; 2 - Turntable system; 3 - Signal processing system, 31 - First correction module, 311 - Inverse Fourier transform unit, 312 - First calculation unit, 313 - Screening unit, 314 - Deformation offset determination unit, 315 - Correction unit; 32 - Second correction module, 321 - First acquisition unit, 322 - Second calculation unit, 323 - Second acquisition unit, 324 - Fitting unit, 325 - Elimination unit; 33 - Preprocessing module, 331 - Redundant signal processing unit, 332 - Segmentation unit; 34 - Imaging stitching module, 341 - Range image stitching unit, 342 - Coordinate system conversion unit, 343 - Output unit; 4 - Control system. Detailed implementation manners

[0053] Reference is made herein to the various aspects and features of the present application with reference to the accompanying drawings.

[0054] It should be understood that various modifications can be made to the embodiments applied herein. Therefore, the above description should not be construed as limiting, but merely as an example of the embodiments. Those skilled in the art will envision other modifications within the scope and spirit of the present application.

[0055] The accompanying drawings, which are included in and constitute a part of this specification, illustrate embodiments of the present application and, together with the general description of the present application given above and the detailed description of the embodiments given below, serve to explain the principles of the present application.

[0056] These and other features of the present application will become apparent from the following description of the preferred forms of the embodiments, given by way of non - limiting example with reference to the accompanying drawings.

[0057] It should also be understood that although the present application has been described with reference to some specific examples, those skilled in the art can surely implement many other equivalent forms of the present application.

[0058] When taken in conjunction with the accompanying drawings, the above and other aspects, features and advantages of the present application will become more apparent in view of the following detailed description.

[0059] Specific embodiments of the present application are described hereinafter with reference to the accompanying drawings; however, it should be understood that the embodiments applied are merely examples of the present application and can be implemented in various ways. Well - known and / or repetitive functions and structures are not described in detail to avoid obscuring the present application with unnecessary or redundant details. Therefore, the specific structural and functional details applied herein are not intended to be limiting, but merely as a basis for the claims and a representative basis for teaching those skilled in the art to use the present application in substantially any suitable detailed structure in a variety of ways.

[0060] Figure 1 shows a schematic structural diagram of a portable omnidirectional true-aperture ground-based radar according to an embodiment of the present application. As Figure 1 shown, an embodiment of the present application provides a portable omnidirectional true-aperture ground-based radar. The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The portable omnidirectional true-aperture ground-based radar includes:

[0061] A signal transceiver system 1, which is equipped with an antenna 11 for transmitting and receiving radar signals;

[0062] A turntable system 2, which is used to drive the signal transceiver system 1 to rotate so as to transmit and receive radar signals at different angles;

[0063] A signal processing system 3, which includes a first correction module 31 and a second correction module 32. The first correction module 31 is used to correct the deformation offset caused by the installation error of the signal transceiver system 1 and the turntable system 2 and the repeated positioning error of the turntable system 2. The second correction module 32 is used to correct the self-coupling signal in the radar signal;

[0064] A control system 4, which is respectively connected to the signal transceiver system 1, the turntable system 2, and the signal processing system 3 to control the operation of the signal transceiver system 1, the turntable system 2, and the signal processing system 3.

[0065] The portable omnidirectional true-aperture ground-based radar provided by the embodiment of the present application uses a true-aperture antenna to transmit and receive signals. At the same time, by setting the first correction module 31, the non-ideal radius caused by the installation error between the antenna 11 and the turntable system 2 and the deformation offset caused by the repeated positioning error of the turntable system 2 are corrected. By setting the second correction module 32, the self-coupling signal generated due to the close spacing of the true-aperture antennas is corrected, improving the deformation inversion accuracy of the radar, thereby improving the monitoring accuracy of the radar.

[0066] Specifically, in this embodiment, the antenna 11 is a dual true-aperture antenna, including a transmitting antenna and a receiving antenna, to transmit and receive signals respectively. The horizontal beam width of the antenna 11 is θ 水平 , and the elevation beam width is θ 俯仰 . The antenna 11 has a high gain and a high radiation energy coefficient, which can improve the signal-to-noise ratio of the observation scene.

[0067] The outer contour of the antenna 11 is rectangular, with the horizontal side length being a and the elevation side length being b, and a > b. Compared with the conventional horn-shaped antenna, it can improve the horizontal resolution and increase the scanning range of the scanning scene in the elevation direction. In particular, the antenna 11 is composed of multiple array element microstrip antennas to form the above-mentioned rectangular antenna 11.

[0068] In this embodiment, a true-aperture antenna is adopted, which is convenient for radar deployment, easy to carry, has a wide range of applications, and can achieve omnidirectional monitoring (including horizontal and pitch directions).

[0069] In some embodiments, the signal transceiver system 1 controls the antenna 11 to transmit and receive signals through a frequency-modulated continuous wave (FMCW) working system, and the transmitted signal is a frequency-modulated continuous wave signal composed of multiple sub-pulse signals.

[0070] Specifically, the antenna 11 installed in the signal transceiver system 1 receives the echo signal of the antenna while transmitting the signal, and the transmitted frequency-modulated continuous wave signal is expressed as:

[0071]

[0072] where f c is the system operating frequency, t is the range-time variable, and t ∈ [-T r / 2, T r / 2], T r is the signal duration, K r is the signal frequency modulation rate, and the signal bandwidth is B r = K r T r .

[0073] In actual processing, in order to facilitate the subsequent self-calibration processing of the interference phase deformation offset caused by the turntable repeat positioning error and the non-ideal radius by the first calibration module 31, and the calibration processing of the self-coupling signal by the second calibration module 32, in this application, the transmitted signal includes N groups of sub-pulses; its expression is:

[0074]

[0075] where rect represents the time window function, T represents the sub-pulse duration, and since there is an interval between sub-pulse groups, T is greater than Tr;

[0076] Assume that the scene target point is P. In the echo signal received by the antenna 11, the echo expression of the sub-pulse frequency modulation signal is:

[0077]

[0078] The intermediate frequency signal expression S IF (t) after mixing the complete signal composed of the above sub-pulse signals by the down mixer is:

[0079]

[0080] where R Pis the distance from the target point P to the antenna aperture plane in the scenario, and C is the speed of light.

[0081] In some embodiments, such as Figure 1 and Figure 2 shown, the signal processing system 3 further includes a preprocessing module 33. Specifically, the preprocessing module 33 includes:

[0082] A redundant signal processing unit 331 for processing redundant signals in the acquired signals;

[0083] A splitting unit 332 for splitting each sub-pulse in each angle direction.

[0084] Specifically, in this embodiment, the redundant signal processing unit 331 is used to process the redundant phase of the signal. The processing flow is to collect the whole signal (a complete signal composed of multiple sub-pulse signals) at each rotation scale (rotation angle) of the turntable system 2, and respectively compensate the redundant phase terms of each sub-pulse in the whole signal at each rotation angle.

[0085] After compensation, the complete signal is:

[0086]

[0087] Among them, is the scattering intensity coefficient of the target p, represents all point targets in the scenario.

[0088] The splitting unit 332 performs splitting of each sub-pulse according to the redundant acquisition points in a period of time between sub-pulses, then performs windowing processing in the transverse distance direction and determines the data storage format. Multiply each sub-pulse signal under the whole signal by a cosine window to suppress the sidelobe; then, arrange the processed data in the format of three-dimensional data, and its dimension is M*N*Q. M represents the actual number of sampling points of the sub-pulse signal after the acquired signal is AD-converted, and is stored in the form of rows. N represents the signals acquired by the turntable system 2 at each angle, and is stored in the form of columns. The data storage formats are as follows:

[0089]

[0090]

[0091] Among them, the value range of n is n∈(1,N), representing the number of sampling points in the angle direction; m represents the number of sampling points in the distance direction, m∈(1,M); the value range of q is q∈(1,Q), representing a set of data.

[0092] In some embodiments, such as Figure 3 shown, the first correction module 31 specifically includes:

[0093] An inverse Fourier transform unit 311 for performing a range-direction inverse Fourier transform on a signal;

[0094] A first calculation unit 312 for calculating the stability of the signal according to the signal transformed by the inverse Fourier transform unit 311;

[0095] A screening unit 313 for screening signals that meet preset conditions according to the stability of the signal;

[0096] A deformation offset determination unit 314 for calculating the deformation offset caused by the non-ideal radius and the repeat positioning error of the turntable system 2;

[0097] A correction unit 315 for correcting the deformation offset.

[0098] Specifically, the inverse Fourier transform unit 311 performs a horizontal range-direction inverse Fourier transform (IFFT) operation on the signal processed by the redundant signal processing unit 331 using the row vectors in the two-dimensional matrix of each page of data. The general term of the processed sub-pulse expression is:

[0099]

[0100] The first calculation unit 312 calculates the stability of the signal using the row vector data of the two-dimensional matrix in each page of data for the signal after the transformation operation by the inverse Fourier transform unit 311; wherein, the expression for stability is:

[0101]

[0102] wherein, ε is the variance of all row vectors in each page of data, is the mean value of all row vectors in each page of data;

[0103] After the calculation by the first calculation unit 312, a two-dimensional matrix of stability coefficients is finally obtained; its arrangement form is as follows:

[0104]

[0105] wherein, M represents the total number of data points collected in the range direction; N represents the total number of data points in the angle direction.

[0106] Further, through the screening unit 313, the target positions with high stability coefficient SS 稳定系数mn are screened and retained; for example, a threshold TT 阈值 is set, and the stability coefficients greater than this threshold TT 阈值 are retained with their original values, and the stability coefficients less than this threshold TT 阈值 are set to 0 to eliminate data with low stability values.

[0107] The deformation offset determination unit 314 calculates the offset caused by the non-ideal radius and the repeat positioning error of the turntable system 2 at a certain angle; cyclically stepwise searches for the maximum value of the coherence coefficient, and the step size obtained by it is the offset. The specific process is as follows:

[0108] Step S1: Accumulate the complex signals after range compression of multiple sub-pulse signals of the same transmitted signal to form a signal of a single sub-pulse after accumulation; the specific operation is: the data stored in the preprocessing module 33 is processed by the inverse Fourier transform unit 311 in the first correction module 31 and then accumulated along the page direction axis in the form of a row vector.

[0109] Step S2: Calculate the one-dimensional matrix correlation quantity, and the expression of the correlation quantity is:

[0110]

[0111] Among them, 1 and 2 in the formula represent the identifiers of two one-dimensional data that need to participate in the calculation of the correlation quantity; and are respectively the data means that need to participate in the calculation of the correlation quantity.

[0112] Take the same row data in the SS 稳定系数 matrix in two adjacent track data selected by the screening unit 313 to participate in the calculation of the correlation quantity, and and A 1m A 2m Replace with the same row data of two adjacent track SS 稳定系数 ; thus, the matrix correlation quantity at a fixed angle can be obtained.

[0113] Step S3: Construct a search mobile compensation factor, and the expression of the mobile compensation factor is:

[0114] S com (f,θ=θ0)=exp(1j*3*pi*f*2*num*ΔR / C) (11)

[0115] Among them, f=[-M / 2-1:M / 2]*C / (2*rbin); rbin=C / (2Br); ΔR is the mobile step size; num is the number of mobile times; therefore, the initial values, namely the mobile step size ΔR and the number of mobile times 0 to num, need to be set before the operation max .

[0116] Step S4: Compensate the signal according to the constructed mobile compensation factor; the specific operation is: on the basis of performing the inverse Fourier transform on the signal by the inverse Fourier transform unit 311, for the signal S IFFT (t,θ n)Perform a range - direction Fourier transform (FFT) operation, multiply the signal after the Fourier transform operation by the above - mentioned motion compensation factor, and finally perform an inverse Fourier transform (IFFT) operation.

[0117] Step S5: Calculate and store the correlation quantity. The process of calculating the correlation quantity can be referred to the above - mentioned step S2; when the number of movements num = num max When it reaches this value, that is, stop the loop action and execute step S5; if it is less than this value, num = num + 1, and continue to repeat step S3 until the offset is obtained.

[0118] Based on the index of the maximum value of the correlation quantity at a certain angle extracted, calculate its movement amount, which is the offset. The correction unit 315 can then compensate the signal according to the constructed motion compensation factor through the above - mentioned step S4, thus completing the compensation and correction of the offset caused by the non - ideal radius of the antenna 11 and the repeat positioning error of the turntable system 2.

[0119] The greater the non - ideal radius of the antenna 11 and the repeat positioning error of the turntable system 2, the worse the data correlation at a certain angle between adjacent two tracks of data. In this embodiment, Q sub - pulse linear frequency - modulated continuous - wave signals are transmitted at one time, and the advantage of the number of sub - pulses is used to obtain the stability coefficient matrix; eliminate the points with low quality; retain the high - quality points to participate in the operation of data correlation, provide a more accurate way to measure data correlation, get rid of the influence of noise on the correlation, facilitate subsequent correction. At the same time, by moving to construct the phase compensation factor, search for the position with the maximum data correlation, that is, the offset caused by the above - mentioned error, and then perform compensation and correction, which can effectively improve the radar deformation inversion accuracy.

[0120] In some embodiments, as Figure 4 shown, the second correction module 32 specifically includes:

[0121] The first acquisition unit 321 is used to acquire the azimuth - direction data of the two - dimensional matrix in each page with a stability exceeding the threshold, and arrange the azimuth - direction data in order to obtain the data matrix D new ;

[0122] The second calculation unit 322 is used to disorderly arrange the data matrix D new and calculate the covariance matrix;

[0123] The second acquisition unit 323 is used to obtain the DC component of each column matrix according to the Fourier transform, and record the distance value corresponding to the column of the matrix;

[0124] The fitting unit 324 is used to fit and obtain the one - dimensional range - direction of the self - coupling signal;

[0125] The elimination unit 325 is used to remove the fitted self - coupling signal from the overall signal.

[0126] Specifically, the first acquisition unit 321 acquires the angular data of the two-dimensional matrix in each page with a stability exceeding the threshold, and eliminates the column with a stability coefficient of 0 screened by the screening unit 313 of the first correction module 31; then rearranges the angular data in ascending order of distance; and forms a new data matrix D new ; D new is N*rand(value); where rand(value) represents a random value, and any one of the Q pages can be operated here.

[0127] The second calculation unit 322 randomly arranges the angular data of the new data matrix D new in the form of permutation and combination; and regenerates D new , this variable is updated at all times, but the serial number of each time will be recorded for subsequent recovery, and then the maximum eigenvalue of the covariance matrix of the D new matrix is obtained, the serial number and the maximum eigenvalue are recorded, and then the serial number corresponding to the largest eigenvalue is selected for subsequent processing. The formula of the covariance matrix is a well-known theory and will not be elaborated here.

[0128] The second acquisition unit 323 uses Fourier (FFT) transform to obtain the DC component, and randomly arranges to disrupt the signal correlation of adjacent components, which increases the high-frequency quantity of the uncoupled signal. However, the consistency of the self-coupled signal is always very high; therefore, according to the D new matrix corresponding to the serial number calculated in the second calculation unit 322, the DC component of each column matrix is obtained and the distance value corresponding to the column of the matrix is recorded.

[0129] The fitting unit 324 fits to obtain the one-dimensional range profile of the self-coupled signal, that is, the amplitude value corresponding to the range is obtained, and the fitting operation is performed in the form of the function sin(pi*x) / (pi*x), and finally the one-dimensional range compression signal of the self-coupled signal is obtained.

[0130] The elimination unit 325 removes the self-coupled signal fitted by the fitting unit 324 from the overall signal, so as to achieve the purpose of removing the self-coupled signal.

[0131] Since the turntable system 2 collects data by rotating a fixed angle each time, but the self-coupling signals in one track of its signals have a relatively high similarity, and the data in adjacent acquisition intervals has a certain degree of correlation. Therefore, in this embodiment, the second correction module 32 is used to randomly arrange the above matrix to weaken the correlation between adjacent acquisition data, and then the covariance matrix characteristics of the data matrix are obtained to find the maximum eigenvalue (representing a large degree of difference between data); the high-frequency components of the newly arranged data have a maximum offset relative to the original data, increasing the frequency point distance from the low frequency. At this time, by means of Fourier transform operation to extract the DC component, the signal can be highly approximated as a self-coupling signal; finally, the self-coupling signal is obtained by fitting and eliminated.

[0132] In some embodiments, such as Figure 1 and Figure 5 shown, the signal processing system 3 further includes an imaging stitching module 34 for imaging the signals corrected by the first correction module 31 and the second correction module 32.

[0133] The imaging stitching module 34 specifically includes:

[0134] The range image stitching unit 341 is used to accumulate the data stored after being processed by the preprocessing module 33 in the form of row vectors along the page direction axis. At the same time, the angle data recorded by the control system 4 are arranged in ascending order, and each angle data will be stored in a two-dimensional matrix following the accumulated data, obtaining the stitched two-dimensional radar image data. In the two-dimensional matrix, the vertical axis dimension is the angle direction representing the actual angle position of the scene target, and the horizontal axis dimension is the range direction representing the distance of the actual scene target;

[0135] The coordinate system conversion unit 342 is used to perform coordinate system conversion on the stitched two-dimensional radar image data. Since the two-dimensional radar image data is stored in polar coordinates when using the range image stitching unit 341 for range stitching, in order to make the scene more intuitive, it is necessary to use the coordinate system conversion unit 342 to convert the polar coordinate image to a rectangular coordinate system;

[0136] The output unit 343 is used to output the imaging result after coordinate system conversion and store the data of the imaging result in a fixed format. After being processed by the imaging stitching module 34, it can enter the deformation inverse solution.

[0137] The control system 4 controls the operation of the signal transceiver system 1, the turntable system 2, and the signal processing system 3.

[0138] Specifically, the control system 4 can first perform system parameter settings, such as setting the maximum rotation angle of the turntable system 2 (i.e., the angle range of the observed scene) and the rotation angle scale.

[0139] After being triggered by a start button or the like, the control system 4 can control the operation of the above signal transceiver system 1 and turntable system 2, and control the signal processing system 3 to process the collected signals after the signals are collected.

[0140] The turntable system 2 rotates at fixed angular intervals. After the rotation of the turntable system 2 stops, the signal transceiver system 1 is immediately triggered to transmit signals into the scene and receive the energy signals (echo signals) reflected by the scene targets. After the AD acquisition is completed, the data is stored, and the angular position information of the turntable system 2 is recorded; when the rotation angle θ of the turntable at this moment < θ max , and not all the rotation angles are collected, continue to control the turntable system 2 to rotate at fixed angular intervals to collect signals; when the angle θ of the turntable = θ max , it is determined that the acquisition of one track of data is completed. After the acquisition of one track of data is completed, the above-mentioned preprocessing module 33, first correction module 31, and second correction module 32 can be used to correct the collected data, and after the data correction is completed, it is output and displayed through the imaging stitching module 34 to obtain a high-precision image.

[0141] Figure 6 The flowchart of the control method of the portable omnidirectional true-aperture ground-based radar according to the embodiment of the present application is shown. As Figure 6 shown, the embodiment of the present application also provides a control method for a portable omnidirectional true-aperture ground-based radar. The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The portable omnidirectional true-aperture ground-based radar includes a signal transceiver system 1, a turntable system 2, and a signal processing system 3. The control method includes:

[0142] S601: Control the antenna 11 installed in the signal transceiver system 1 to transmit and receive radar signals;

[0143] S602: Control the turntable system 2 to rotate to drive the signal transceiver system 1 to rotate to transmit and receive radar signals at different angles;

[0144] S603: Control the first correction module 31 and the second correction module 32 of the signal processing system 3 to correct the radar signals. The first correction module 31 is used to correct the installation errors of the signal transceiver system 1 and the turntable system 2 and the deformation offset caused by the repeated positioning error of the turntable system, and the second correction module 32 is used to correct the self-coupling signals in the radar signals.

[0145] In this embodiment, mainly the echo signals received based on the transmitted signals are corrected. For the working processes of the signal transceiver system 1 and the turntable system 2, and the processing process of the signal processing system 3, reference can be made to the above-mentioned portable omnidirectional true-aperture ground-based radar.

[0146] Since the control method of the portable omnidirectional true-aperture ground-based radar provided by the embodiments of the present application corresponds to the above-mentioned portable omnidirectional true-aperture ground-based radar, based on the above-mentioned portable omnidirectional true-aperture ground-based radar, those skilled in the art can understand the specific implementation manners and various variations of the control method of the portable omnidirectional true-aperture ground-based radar in the embodiments of the present application. Any optional items in the embodiments of the portable omnidirectional true-aperture ground-based radar are also applicable to the control method of the portable omnidirectional true-aperture ground-based radar, and will not be elaborated herein.

[0147] The above embodiments are only exemplary embodiments of the present application and are not used to limit the present application. The protection scope of the present application is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions within the essence and protection scope of the present application, and such modifications or equivalent substitutions should also be regarded as falling within the protection scope of the present application.

Claims

1. A portable omnidirectional true-aperture ground-based radar, characterized in that, The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The portable omnidirectional true-aperture ground-based radar includes: A signal transceiver system equipped with an antenna for transmitting and receiving radar signals; A turntable system for driving the signal transceiver system to rotate to transmit and receive radar signals at different angles; A signal processing system including a first correction module and a second correction module. The first correction module is used to correct the deformation offset caused by the installation error of the signal transceiver system and the turntable system and the repeated positioning error of the turntable system. The second correction module is used to correct the self-coupling signal in the radar signal; A control system respectively connected to the signal transceiver system, the turntable system, and the signal processing system to control the operation of the signal transceiver system, the turntable system, and the signal processing system; where: The first correction module includes a deformation offset determination unit, and the deformation offset determination unit is used to: Accumulate the complex signals after range compression of multiple sub-pulse signals of the same transmitted signal to form a signal of a single sub-pulse after accumulation; Calculate the one-dimensional matrix correlation quantity; Construct a search motion compensation factor; Compensate the signal according to the constructed motion compensation factor; Obtain and store the correlation quantity.

2. The portable omnidirectional true-aperture ground-based radar according to claim 1, wherein The signal transceiver system controls the antenna to transmit and receive signals through a frequency-modulated continuous-wave working system. The transmitted signal is a frequency-modulated continuous-wave signal composed of multiple sub-pulse signals.

3. The portable omnidirectional true-aperture ground-based radar according to claim 1, characterized in that The first correction module further includes: An inverse Fourier transform unit for performing an inverse Fourier transform on the signal in the range direction; A first calculation unit for calculating the stability of the signal according to the signal transformed by the inverse Fourier transform unit; A screening unit for screening signals that meet preset conditions according to the stability of the signal; A correction unit for correcting the deformation offset.

4. The portable omnidirectional true-aperture ground-based radar according to claim 3, characterized in that The screening unit screening signals that meet preset conditions according to the stability of the signal includes: Greater than a preset threshold value TT 阈值 Keep the stability coefficient unchanged to screen and retain the stability coefficient SS 稳定系数mn with a high target position; Set the stability factor less than the preset threshold TT 阈值 to 0.

5. The portable omnidirectional true-aperture ground-based radar according to claim 1, characterized in that, The second correction module includes: A first acquisition unit, configured to acquire angular data of two-dimensional matrices in each page with a stability exceeding a threshold, and arrange the angular data in sequence to obtain a data matrix D new ; A second computing unit for scrambling the data matrix D new and calculating a covariance matrix; A second acquisition unit for obtaining the DC component of each column matrix according to Fourier transform and recording the range value of the corresponding column of the matrix; A fitting unit for fitting to obtain the one-dimensional range direction of the self-coupling signal; An elimination unit for removing the fitted self-coupling signal from the overall signal.

6. The portable omnidirectional true-aperture ground-based radar according to claim 1, characterized in that, The signal processing system further includes a preprocessing module, and the preprocessing module includes: A redundant signal processing unit for processing redundant signals in the acquired signals; A segmentation unit for segmenting each sub-pulse in each angular direction.

7. The portable omnidirectional true-aperture ground-based radar according to claim 6, characterized in that The signal processing system further includes an imaging stitching module, and the imaging stitching module includes: A range-direction image stitching unit for accumulating the data processed by the preprocessing module in the form of row vectors along the page direction axis, and at the same time arranging the angular data recorded by the control system in ascending order and forming a two-dimensional matrix with the accumulated data to obtain the stitched two-dimensional radar image data; A coordinate system conversion unit for performing coordinate system conversion on the stitched two-dimensional radar image data; An output unit for outputting the imaging result after coordinate system conversion and storing the data of the imaging result in a fixed format.

8. The portable omnidirectional true-aperture ground-based radar according to any one of claims 1 to 7, characterized in that, The antenna is a dual real-aperture antenna, including a transmitting antenna and a receiving antenna. The outer contour of the dual real-aperture antenna is rectangular, and the horizontal side length is greater than the pitch side length.

9. Control method for a portable omnidirectional true-aperture ground-based radar, characterized in that, The portable omnidirectional true-aperture ground-based radar uses the true-aperture principle for imaging and information extraction. The portable omnidirectional true-aperture ground-based radar includes a signal transceiver system, a turntable system, and a signal processing system. The control method includes: Controlling the antenna installed in the signal transceiver system to transmit and receive radar signals; Controlling the turntable system to rotate to drive the signal transceiver system to rotate to transmit and receive radar signals at different angles; Controlling the first correction module and the second correction module of the signal processing system to correct the radar signals. The first correction module is used to correct the deformation offset caused by the installation error of the signal transceiver system and the turntable system and the repeated positioning error of the turntable system. The second correction module is used to correct the self-coupling signal in the radar signals. Wherein: The first correction module includes a deformation offset determination unit, and the deformation offset determination unit is used for: Accumulating the complex signals after range compression of multiple sub-pulse signals of the same transmitted signal to form a signal of a single sub-pulse after accumulation; Calculating the one-dimensional matrix correlation quantity; Constructing a search mobile compensation factor; Compensating the signal according to the constructed mobile compensation factor; Obtaining and storing the correlation quantity.

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