83 results about "Range migration" patented technology

A linear chirp radar system, apparatus and method use a radar control processing unit to control an LFM radar front end which generates analog-to-digital (ADC) sample signals from one or more target return signals received in response to transmitted linear chirp radar signals, where the radar control processing unit is connected and configured to mitigate range migration by directly filtering the ADC samples using a modified Doppler filter that is tuned to fast-time scaled, slow-time frequencies to generate a focused ADC Doppler cube, and by applying a Fourier Transform on each Doppler cell in the focused ADC Doppler cube to generate a focused range-Doppler cube.

The invention discloses a multi-scattering SAR (Synthetic Aperture Radar) imaging simulation method, system and device based on physical consistency modeling and a medium. The method comprises the following steps: constructing a three-dimensional electromagnetic model of a target; constructing a geometric model under the working mode of the ray tracing auxiliary transmitting-receiving co-located SAR; a high-frequency electromagnetic scattering algorithm based on ray tracing is adopted, multiple scattering paths of a first order, a second order and a higher order are considered, superposition and amplitude modulation are carried out on scattering contributions of all orders, scattering field distribution of a target under the far field condition is calculated, and a far-field scattering field is obtained; performing spatial propagation mapping on the total far-field scattering field, and mapping a far-field scattering result into a radar platform near-field echo signal; correcting the amplitude of the echo signal to obtain a two-dimensional SAR near-field echo matrix; sAR imaging processing is carried out, wherein the SAR imaging processing comprises distance compression, range migration correction (RCMC) and azimuth compression. According to the invention, the authenticity and precision of SAR imaging simulation in a complex target scene are improved.

The invention discloses an imaging method, system and device for correcting range migration based on frequency domain phase multiplication, and the method comprises the following steps: carrying out the range pulse compression of echo data of each receiving array element in a range frequency domain; performing data preprocessing according to a phase center approximation method to obtain equivalent transmit-receive combined synthetic aperture sonar data; deriving a secondary distance compression item at the reference distance in the two-dimensional frequency domain, and performing secondary distance compression processing; deriving a space-variant migration phase term of range migration correction corresponding to each target with different distances; carrying out filtering processing on the two-dimensional frequency domain sonar data; a filtered result is converted to a range-direction time domain and an azimuth-direction Doppler domain, data of targets at corresponding distances are extracted, and the data extracted each time are combined in sequence; and for the data after range migration correction, azimuth pulse compression is carried out in a range time domain and an azimuth Doppler domain, and the data is converted to a two-dimensional time domain to obtain a sonar image.

The invention discloses a bistatic radar high-speed target detection method based on space-time Doppler coherent accumulation, and the method comprises the steps: building a bistatic array radar system signal echo model, and carrying out the pulse compression processing of radar echo data; based on the array receiving signal, the direction matrix of the receiving beam and the corresponding weight vector, performing simultaneous multi-beam forming processing on the signal after pulse compression to obtain a signal after beam forming; constructing a beam compensation function; performing transformation compensation on the signal after beam forming by using a beam compensation function to obtain a signal after beam walking correction; performing line demodulation processing on each beam of the signal after beam walking correction to obtain a two-dimensional signal of a distance-modulation frequency domain; and detecting to obtain a target detection result. According to the method, the effects of range migration, pitching beam migration, azimuth beam migration and Doppler frequency migration can be effectively eliminated, the detection performance of the high-speed moving target is improved, and accurate positioning and speed estimation of the high-speed moving target are realized.

The invention relates to the technical field of synthetic aperture radar signal processing, and discloses a CS imaging method based on an ultrahigh-resolution slip SAR high-order slope distance model, and the method comprises the steps: building a high-order slope distance model based on the ephemeris parameters of a synthetic aperture radar satellite and the position information of an imaging target; determining a first expression of an original echo signal of a synthetic aperture radar satellite in a two-dimensional frequency domain and a second expression of the original echo signal in a distance Doppler domain based on a high-order slant-range model, and constructing a phase compensation function based on the first expression and the second expression; and performing range compression, range migration correction, secondary range compression and azimuth compression based on the phase compensation function to generate a focused synthetic aperture radar image. According to the method, universality description can be carried out on the slant range process of the SAR satellites running in different eccentricity rate orbits, and high precision can be kept.

The invention provides a multilayer medium efficient imaging method suitable for frequency modulation continuous wave ice radar data, and belongs to the field of frequency modulation continuous wave ice radar imaging. Comprising the steps of multi-layer medium signal model construction, improved distance-Doppler algorithm implementation, distance migration accurate correction and azimuth focusing processing. According to the method, a multi-layer medium signal model containing refractive index and propagation velocity changes is established for the problem of target distance distortion caused by propagation velocity differences of electromagnetic waves in different media such as ice and snow; based on the model, a traditional distance-Doppler algorithm process is improved, distance migration caused by multiple layers of media is accurately corrected by introducing a medium-dependent distance migration factor, and efficient azimuth focusing is achieved. And finally, a high-resolution ice layer internal structure image can be generated, and the method is suitable for polar region large-range ice cover detection and rapid processing of a large amount of ice radar data.

A method for compensating for time-frequency synchronization errors in a bistatic SAR based on a maximum contrast method relates to an airborne bistatic SAR imaging method. The purpose of the present invention is to solve the problem of target imaging defocus caused by time-frequency synchronization errors in airborne bistatic SAR. The process is as follows: first, a bistatic SAR system is used to record echo signals of scene targets, a transmitter transmits an LFM signal, which is received by a receiver after being reflected by the scene target, and target echo data is obtained; second, range frequency domain data is obtained; third, echo data after matched filtering is obtained; fourth, echo data after range migration correction is obtained; fifth, echo data after azimuth compression is obtained; sixth, two-dimensional image contrast is obtained for the echo data after azimuth compression; seventh, the correction factor E1 and the compression factor E2 are used as variables, and a particle swarm optimization algorithm is used to obtain the echo data corresponding to the maximum value of the two-dimensional image contrast and compensated for the time-frequency synchronization error as the final target image. The present invention is used in the field of target imaging.

The invention discloses an arc SAR imaging method and system, and the method comprises the steps: S1, building a radar signal model and a motion geometric model, and deducing the distance history of a target point at different moments; s2, converting the range history into a Doppler frequency domain, analyzing a corresponding relation between range migration and Doppler frequency, designing a phase compensation coefficient, and correcting the range migration of the Doppler frequency domain in a time domain to obtain corrected range data; s3, analyzing the spectral characteristics of the azimuth response function, and estimating an effective support domain based on an energy approximation threshold; s4, performing azimuth accumulation on the spectrum data in the support domain by using Chirp-Z transformation to obtain an azimuth accumulation result; and S5, outputting an SAR imaging result in combination with the corrected range direction data and the azimuth direction accumulation result. The method has the advantages that the calculation complexity and the memory required by calculation can be reduced, and the like.

The invention discloses a switching judgment method and device for a low-orbit satellite communication coverage area, and relates to the technical field of satellite communication. The method comprises the following steps: determining a first scanning wave position set of each wave beam of a low-orbit satellite in a current coverage area; determining a second scanning wave position set of each wave beam when the low-orbit satellite migrates to the next coverage area; according to the first scanning beam position set and the second scanning beam position set of each beam, determining a virtual beam position scanning scheme of each beam in a next-hop beam period by using a genetic algorithm; judging whether each beam is subjected to beam migration in a next-hop beam period or not; and migrating the communication coverage range of the low-orbit satellite to the next coverage area in the next-hop beam period under the condition that the number of the beams subjected to beam migration is judged to reach the preset threshold value. Therefore, the method can adapt to the scanning characteristics and coverage requirements of different beams of the multi-beam low-orbit satellite based on the independent judgment logic of each beam.

The invention discloses a strabismus mode ground interference source positioning method and system based on a satellite platform, a storage medium and electronic equipment, and the method comprises the following steps: firstly, carrying out the range pulse compression of a received interference signal according to the related parameters estimated by the prior information of an orbit and the time-frequency relation; constructing a matched filter, realizing linear range migration correction, and eliminating a first-order component of range migration in a range frequency domain-azimuth time domain; a CTF search algorithm is used, and under different search distances, distance direction search is achieved through a cooperation mechanism of global search and step length constraint local optimization; constructing matched filters at different distances to realize quadratic term range migration correction, and eliminating a range migration quadratic term in a two-dimensional frequency domain; azimuth distance compression is carried out at different distances, so that signals are focused; and obtaining a two-dimensional positioning position opposite to the interference source through coordinate transformation. According to the invention, the problem of signal defocusing caused by the distance-orientation strong coupling effect is solved in the squint mode, and the interference source positioning precision is significantly improved.

The invention discloses an airborne bistatic radar clutter suppression and target accumulation detection combined implementation method, which is applied to the technical field of radars, and aims to solve the problems of range migration, Doppler migration and strong clutter noise background when an airborne bistatic radar detects a low-altitude maneuvering target. According to the method, non-stationary clutters are effectively suppressed and range migration and Doppler migration are corrected and compensated by utilizing two-stage sliding sub-aperture space-time processing, target signal reconstruction and sub-aperture segmented accumulation, so that coherent accumulation of target multi-pulse energy is realized; finally, the purposes of improving the echo signal-clutter-noise ratio and improving the maneuvering target detection performance of the bistatic radar are achieved.

This application relates to a terahertz video synthetic aperture radar moving target imaging method based on time-frequency analysis. The method includes: constructing a radar echo model of the moving target based on instantaneous range and radar echo; processing the radar echo model by performing a short-time Fourier transform on the compressed echo signal; obtaining the Doppler center frequency of the scene echo from the obtained time-frequency distribution map; performing Doppler frequency zero-padding, range migration correction, and azimuth processing on the compressed echo signal according to a pre-set function; observing the range cell position of the moving target from the obtained imaging results; and extracting and performing time-frequency analysis on the moving target signal. After determining the Doppler center frequency of the moving target through time-frequency analysis and the time-frequency map, velocity estimation is performed; and the image of the moving target is refocused based on the characteristics of the time-frequency distribution line of the moving target echo. This method can quickly achieve velocity estimation and image refocusing of moving targets.

The application relates to a space target joint imaging and attitude inversion method based on a spaceborne platform, and relates to the field of inverse synthetic aperture radar imaging, in particular to a space target joint imaging and attitude inversion method based on a spaceborne platform. The application aims to solve the problems that in the existing space target imaging process of a spaceborne platform, three-dimensional high-order space-variable range migration and phase errors caused by complex relative motion between the target and the platform are difficult to realize high-precision imaging, and the existing attitude estimation algorithm needs to be completely compensated for the rectangular component segmentation and orbit error before the attitude inversion can be realized. The process is as follows: one, a narrowband tracking system of a radar obtains target slant range and a radar line-of-sight unit vector; two, a wedge-shaped transformed signal is obtained; three, spatial Doppler parameter distribution of a special point is obtained; four, an imaging result is obtained; and five, accurate estimation of target attitude parameters is completed through plane coefficient fitting.

The present invention relates to an underwater acoustic image reconstruction method based on angle error compensation, comprising the following steps: (1) For each subsystem composed of a receiving array element and a transmitting array element, calculate the spatial coordinate information of the transmitting array element and the receiving array element and the two-way slant range history; (2) Calculate the two-way slant range history after phase center approximation; (3) Calculate the system function in the range-Doppler domain; (4) Calculate the Doppler phase error; (5) Divide the data into non-overlapping data blocks and compensate for the micro range migration error caused by the range error; (6) Obtain the signal after range delay error compensation; (7) Perform differential range migration correction processing, range direction pulse compression, secondary range pulse compression, and consistent range migration correction processing; (8) Perform azimuth focusing processing, residual phase error compensation operation, and azimuth walk correction processing; (9) Perform coherent fusion processing and inverse Fourier transform to obtain the final high-resolution image. The present invention can quickly reconstruct images and meet the requirements of real-time processing.

The invention relates to a quality improvement method for a high-resolution image. The method comprises the following steps: obtaining an equal-target two-way slope distance; calculating a distance error; calculating a two-dimensional frequency spectrum; calculating a truncation phase error; obtaining data of each receiving array element after micro-Doppler phase error compensation; obtaining all receiving array element data after micro-range migration error correction; obtaining data of the class receiving and transmitting combined synthetic aperture sonar; obtaining N data blocks after truncation phase error compensation; obtaining multi-receiving array element synthetic aperture sonar data; filtering to obtain filtered data; obtaining the data after the nonlinear frequency modulation processing; calculating an accurate phase; obtaining a system frequency modulation rate after second-order Taylor series approximation; calculating a coefficient of the expression of the delay time and the distance direction frequency; solving an undetermined coefficient; performing high-order phase error compensation; and a high-resolution synthetic aperture sonar image is obtained. According to the method, the reconstruction performance can be effectively improved under the conditions of larger transmission signal bandwidth and larger accumulated beam angle.

The present invention discloses a method for millimeter-wave three-dimensional sparse imaging based on generalized MCP constraint. Firstly, range pulse compression processing of the echo signal is completed by using pulse compression and frequency upsampling techniques; then, the standard range migration correction algorithm is used to process the signal after range pulse compression to complete range migration correction; then, for each range cell, an imaging equation approximating the RMA imaging operator based on generalized MCP non-convex constraint is constructed respectively, and optimized to solve to obtain the corresponding azimuth-height imaging result; finally, the overall three-dimensional sparse imaging result of the target scene is obtained by stacking the imaging results of each range cell along the range direction. Compared with the existing millimeter-wave three-dimensional sparse imaging method based on L1 norm constraint, the method of the present invention is more suitable for the situation of unbalanced energy distribution of scene targets, has small estimation deviation, more complete retention of geometric contours, and high image quality.

The invention discloses a sonar image imaging method, system and device based on a two-step interpolation method. The sonar image imaging method comprises the following steps: calculating a two-dimensional frequency domain system function; second-order approximation is carried out on the distance-direction instantaneous frequency, and a high-order phase approximation error is calculated; for the approximated function, calculating the maximum range migration of the scene and the multiple # imgabs0 # to be interpolated in the subsequent steps, and performing first zero padding on the front end and the rear end of the sonar data in a range direction time domain; performing high-order phase error compensation and range-direction matched filtering in a two-dimensional frequency domain for the zero-filled data; calculating the total number # imgabs 1 # of the range-direction frequency domain data, supplementing # imgabs 2 # zero values to the rear end of the range-direction frequency domain data, and converting the range-direction frequency domain data to a range-direction time domain; aiming at the data of the distance-Doppler domain, according to the distance migration amount corresponding to each distance target, adopting a rounding-off interpolation method to carry out distance migration correction; and carrying out azimuth matched filtering in the distance-Doppler domain and converting to a two-dimensional time domain to obtain a high-resolution image.

The application discloses a kind of high-efficiency motorized weak target long-time coherent accumulation detection methods, belong to radar target detection field;Including the three-scale decomposition of motorized target radial motion parameter variable;In target blur scale motion parameter variable search space eliminates Doppler frequency blur effect;Through Keystone conversion correction first-order range migration caused by motorized target baseband speed;In target coarse scale baseband motion parameter variable search space, estimate motorized target coarse scale baseband motion parameter by GIFT conversion;In target fine scale baseband motion parameter variable search space, estimate motorized target fine scale baseband motion parameter, obtain temporary range-doppler spectrum;According to motorized target motion parameter variable three-scale decomposition model, estimate the complete motion parameter of motorized target;Based on motorized target motion parameter estimation, obtain motorized target range-doppler spectrum.The method has the characteristics of low computational complexity, Doppler blur effective compensation, high detection performance.

The invention discloses a method for imaging a space target by a space-based ISAR (inverse synthetic aperture radar), and relates to the field of inverse synthetic aperture radar imaging, in particular to the method for imaging the space target by the space-based ISAR. The invention aims to solve the problem that high-precision imaging is difficult to realize due to high-order space-variant range migration and phase error caused by complex relative motion and large-bandwidth signals between a target and a platform in a space target imaging process of a space-based ISAR (Inverse Synthetic Aperture Radar). The method comprises the following steps of: 1, acquiring a target slant distance and a radar sight observation angle according to orbit information of a satellite-borne platform, orbit information of a space target and a narrow-band tracking system of the satellite-borne platform; obtaining a radar sight line unit vector based on the radar sight line observation angle; 2, constructing a translational motion compensation item based on a target slant distance, and calculating an imaging compensation coefficient based on a radar line-of-sight unit vector; and 3, performing translational motion compensation by using the translational motion compensation item, performing rotational motion compensation by using the imaging compensation coefficient, and finally obtaining an imaging result.

The present invention relates to the technical field of airport FOD detection, and more particularly to a radar- and camera-based unmanned aerial vehicle (UAV) FOD detection system, comprising a background central radar, a camera, and a detection UAV. The present invention optimizes radar detection when the UAV is equipped with the radar and camera. First, range migration correction is performed on the radar echo signal to compensate for interference with radar detection (echo) caused by the flight speed of the UAV equipped with the radar. Simultaneously, a secondary confirmation is performed on the radar detection. By comparing a large amount of data, secondary screening of FOD detection is performed, reducing invalid detections, increasing detection accuracy, and saving detection time. A fixed-focus camera is used to perform detailed identification of suspected FOD objects by category, size, risk level, etc. after preliminary radar detection, thereby improving detection efficiency and accuracy.

The present invention discloses a method for reconstructing a distortion-free three-dimensional image of a moving ship target on a sea surface using bistatic SAR. First, a bistatic SAR spatial geometric configuration and a model of the moving ship target echo are established, parameter initialization is completed, and the bistatic range history from the bistatic SAR to any scattering point in the moving ship target and the pulse pressure echo of the moving ship target of the bistatic SAR are obtained. The echo is preprocessed to remove Doppler blur in the bistatic SAR echo and correct the range migration of the echo. A projection in the range-center-of-mass-frequency domain is obtained to achieve three-dimensional image reconstruction of the moving ship target. Finally, remapping is performed based on a local Cartesian coordinate system to correct the three-dimensional distortion of the target and achieve distortion-free three-dimensional image reconstruction of the moving ship target on the sea surface. The method of the present invention eliminates image distortion caused by unknown IPP and achieves distortion-free three-dimensional image reconstruction in LCC. Compared with the existing two-dimensional imaging and distorted and uncalibrated results, the information dimension of the target is increased and the information reliability of the target is improved.

The present invention discloses an improved RD imaging method applicable to GEOSAR, including: obtaining the slant range error caused by ionospheric refraction according to the spatio-temporal variation characteristics of the background ionosphere within the synthetic aperture time; obtaining the two-way slant range error value caused by the ionosphere based on the non "stop-go-stop" assumption; obtaining the two-dimensional echo signal expression of GEOSAR; using the series inversion method to obtain the simplified expression of the two-dimensional echo signal of GEOSAR; processing the influence of the ionosphere; compensating the influence of the high-order phase function; range compression and range migration correction; azimuth compression processing; obtaining a clear two-dimensional image of point targets. The improved RD imaging method applicable to GEOSAR provided by the present invention can achieve clear imaging of targets within a large scene range; and the method of the present invention has a small amount of calculation and is convenient to be applied in actual engineering.

The application discloses a kind of vehicle-mounted video SAR imaging methods based on sub-aperture spectrum fusion, comprising: establishing vehicle-mounted SAR sub-aperture imaging model, and determining the instantaneous slant range of arbitrary point P under "walk-stop" assumption;After the difference frequency processing of each sub-aperture signal and transmission signal, difference frequency signal is obtained, and signal after range compression is obtained;The range compressed signal is subjected to azimuth Fourier transform, and two-dimensional frequency domain signal is obtained;Two-dimensional frequency domain signal is subjected to inverse distance Fourier transform and distance curvature compensation, and signal after range migration correction is obtained;The range migration corrected signal is subjected to distance Fourier transform and azimuth compression, and two-dimensional focused first signal is obtained;First frame image is generated using the first M first signals and azimuth compensation function, and the first signal of the i frame and the i-1 frame image overlap, the latest first signal and the time sequence offset function are used to generate the i (i>1) Frame image.The application solves the imaging distortion problem caused by space variation.

The application discloses a GPS external radiation source target echo efficient accumulation method based on PSO and LVD. The method comprises the following steps: acquiring echo signals, and performing cross-correlation processing on the echo signals to obtain pulse compression signals; according to the pulse compression signals, the velocity and acceleration of target motion are estimated by using a PSO algorithm to obtain estimated velocity and acceleration; according to the estimated velocity and acceleration, first-order range migration, second-order range curvature and Doppler frequency migration correction are performed on the pulse compression signals to obtain corrected pulse compression signals; and the corrected pulse compression signals are coherently accumulated by using LVD to obtain a target detection result. The application can obtain a higher signal-to-noise ratio and high gain.

This invention discloses a method for detecting and suppressing azimuth blur in spaceborne SAR scene matching curve imaging, comprising: 1. Modeling the azimuth blur, providing analytical expressions for the azimuth blur echo, range migration correction, and azimuth phase compensation terms; 2. Refocusing the nth-order azimuth blur based on the range migration correction and azimuth phase compensation terms; 3. Calculating the entropy difference between the SAR image and the nth-order blurred refocused image in blocks, and using the CFAR algorithm to detect blurred regions; 4. Filtering using a Wiener filter to generate a low-blur, low-resolution image; and combining the azimuth blur region detection results, replacing the detected sub-blocks to obtain a low-blur, high-resolution image. This invention can solve the azimuth blur problem in spaceborne SAR scene matching curve imaging mode, effectively improving image quality while preserving the resolution of the original image.

The invention discloses a space-time quick forward-looking imaging method for a forward-looking array radar of a motion platform, which comprises the following steps of: firstly, recording forward-looking area echoes by a multi-channel radar system based on a track cutting direction, and sampling to obtain distance-pulse-channel three-dimensional echo data; performing range-direction high-resolution processing, pulse compression and range migration correction on the data; traversing each range gate, performing azimuth Fourier transform on each frame-multichannel space-time two-dimensional data, intercepting a dominant Doppler unit greater than an energy threshold in a Doppler spectrum, and performing inverse Fourier transform to a time domain, namely performing dimension reduction processing in the Doppler domain; then, rank reduction processing is carried out based on the low-rank characteristic of the covariance matrix, and the energy of the signal is reserved through principal component analysis; and finally, estimating the position and amplitude information of the target through an adaptive iteration algorithm, and carrying out projection to obtain a final two-dimensional imaging result. According to the method, while the foresight resolution is effectively improved, the calculation complexity is remarkably reduced, and the operation efficiency is greatly improved.

The present invention discloses a circular arc SAR imaging method and system, comprising the following steps: S1. establishing a radar signal model and a motion geometry model to derive the range history of a target point at different times; S2. converting the range history to the Doppler frequency domain, analyzing the correspondence between range migration and Doppler frequency, designing a phase compensation coefficient, and correcting the range migration in the Doppler frequency domain in the time domain to obtain corrected range data; S3. analyzing the spectral characteristics of the azimuth response function and estimating the effective support domain based on an energy approximation threshold; S4. using a Chirp-Z transform to perform azimuth accumulation of the spectral data within the support domain to obtain an azimuth accumulation result; and S5. combining the corrected range data with the azimuth accumulation result to output a SAR imaging result. The present invention has the advantages of reducing computational complexity and memory requirements.

There is a need to address the problem of compressed scanning in SAR acquisitions for microwave imaging. Embodiments of the present disclosure provide microwave imaging with multiple-input and multiple-output synthetic aperture radar using compressed multi-coset range migration technique. The present disclosure reduces the SAR acquisition time by compressed scanning, where a compressed scanning acquisition setup captures radar measurements to obtain a microwave image of a target scene by intermittently skipping blocks during SAR acquisition. Further, reconstruction of a microwave image of a target scene is performed using 2D Fourier Transform (FT) of the radar measurements based on a multi-coset range-migration framework. The multi-coset range migration framework makes use of intermittent scanning and formulates a compressed sensing-based architecture by leveraging block-sparsity constraints. Subsequently, a denoising convolutional neural network (DnCNN) is used to enhance and denoise the reconstructed microwave image to obtain a high-resolution image of the target scene.

This invention provides a frequency domain imaging method for spaceborne large-angle high-resolution sliding convergence SAR, achieving high-precision imaging of spaceborne large-angle high-resolution sliding convergence SAR. This invention solves the problem of nonlinear variation of the Doppler center of each target point with azimuth time by nonlinear deskewing, and solves the problem of inconsistency of azimuth spatial variables of range migration at different range gates by azimuth resampling, thus making up for the shortcomings of the prior art.

The invention discloses a multi-step frequency scaling arc synthetic aperture radar imaging method, device, equipment and medium, and the method comprises the steps: carrying out the preprocessing of a frequency modulation continuous wave-synthetic aperture radar echo signal, and obtaining a range Doppler domain echo signal after range compression and azimuth Fourier transform; carrying out segmented azimuth frequency scaling processing on the distance Doppler domain echo signal; carrying out complementary range migration correction by adopting range-to-frequency scaling, and carrying out phase multiplication in a range time domain through inverse Fourier transform to realize consistent range migration correction; range Fourier transform is carried out, azimuth frequency inversion scaling and post-processing are completed in a range Doppler domain, and original azimuth bandwidth is recovered; carrying out azimuth matching filtering on the signal of which the original azimuth bandwidth is recovered; and azimuth inverse Fourier transform is carried out on the signal after azimuth matching filtering, and an imaging result is obtained. The method has a smaller phase error, and can improve the problem of over-correction of range migration caused by azimuth bandwidth spread of a close-range target on the premise of ensuring the far-field imaging quality.