49 results about "Range migration" patented technology

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 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.

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.

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 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 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 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.

The application provides a long-time phase accumulation method with combined constraints of operation complexity and detection probability, belongs to the technical field of radar detection, and is mainly used for solving the range-Doppler migration problem of a radar when the radar is used for gazing at a weak maneuvering target. The application adopts Keystone transformation to eliminate range migration, optimizes the number of acceleration channels under the combined condition constraints of operation complexity and detection probability, and adopts double-stage acceleration channel fine Doppler demodulation technology to eliminate Doppler migration based on the optimization, so that long-time phase accumulation is realized.

The invention belongs to the field of radar signal processing, discloses a method for acquiring a one-dimensional range profile of a high-speed moving target by sub-pulse linear frequency modulation emission and inter-pulse frequency agility radar, and realizes frequency agility waveform echo high-speed target detection and correction based on sparse representation. In the prior art, distance and Doppler parameter estimation of target echoes can be generally realized by adopting sparse representation and sparse processing, and orthogonal matching pursuit (OMP) is one of common solution algorithms. The carrier frequency of a frequency agility radar jumps randomly between pulses, and the acquisition of a one-dimensional range profile of a high-speed moving target not only needs to correct inter-pulse range migration, but also needs to compensate intra-pulse range-Doppler coupling generated by the change of the carrier frequency. According to the method, firstly, compensation of intra-pulse distance-Doppler coupling is carried out, then distance migration correction is carried out on each frequency agility pulse based on a KeyStone method, sparse processing is carried out on a corrected echo signal by adopting an orthogonal matching pursuit algorithm, and a high-resolution one-dimensional distance image of a target is obtained. Experimental results show that the one-dimensional range profile processing method for performing inter-pulse range migration correction through the KeyStone algorithm is beneficial to target detection in high-speed motion.

The application discloses a kind of building thermal insulation layer bonding surface radar data acquisition methods, belong to radar data acquisition technical field, for building thermal insulation layer bonding surface data acquisition, including based on the principle of penetration imaging radar acquisition building thermal insulation layer bonding surface data, radar echo data is handled using range migration imaging and robust principal component analysis method, using edge detection method is connected and region filling to image edge, generate building thermal insulation layer bonding surface binary image, based on the method of the application builds building thermal insulation layer bonding surface radar data acquisition experimental platform.The application is collected to building thermal insulation layer bonding surface by radar data, and radar echo and image are optimized, provide scientific basis for evaluating the structural stability and potential risk of bonding layer, improve radar data acquisition precision and image definition;Building thermal insulation layer bonding surface radar data acquisition experimental platform is designed, realizes the method of collecting building thermal insulation layer bonding surface data in laboratory environment.

The invention discloses an external radiation source radar range migration correction method based on star chain communication signals, and belongs to the technical field of external radiation source radars. The method comprises the following steps: performing reconstruction and pulse compression processing on a target echo signal; converting the signal to a range frequency-slow time domain; doppler fuzzy number compensation is carried out; dynamically dividing the frequency spectrum of the signal into a first processing area and a second processing area; performing interpolation correction on the signals of the first processing area by adopting a first type of interpolation Keystone transformation algorithm, and performing interpolation correction on the signals of the second processing area by adopting a second type of interpolation Keystone transformation algorithm; the corrected signals are recombined in the range frequency-slow time domain. According to the method, the interpolation strategy can be adaptively adjusted according to the energy distribution of the star chain communication signal, the calculated amount is remarkably reduced while high-precision range migration correction is ensured, and the method is suitable for high-speed target detection of the external radiation source radar of the star chain communication signal.

The invention discloses a space target combined imaging and attitude inversion method based on a spaceborne platform, and relates to the field of inverse synthetic aperture radar imaging, in particular to the space target combined imaging and attitude inversion method based on the spaceborne platform. The objective of the invention is to solve the problem that high-precision imaging is difficult to realize due to three-dimensional high-order space-variant range migration and phase error caused by complex relative motion between a target and a platform in the process of space target imaging by the existing satellite-borne platform; and an existing attitude estimation algorithm needs to realize attitude inversion on the premise of rectangular part segmentation and complete orbit error compensation. The method comprises the following steps: 1, a narrow-band tracking system of a radar obtains a target slant distance and a radar line-of-sight unit vector; 2, obtaining a signal after wedge transformation; 3, acquiring spatial Doppler parameter distribution of the dominant display point; 4, obtaining an imaging result; and 5, completing accurate estimation of target attitude parameters through plane coefficient fitting.

The application relates to an improved Omega-K imaging method suitable for curve trajectory squinted SAR and belongs to the field of radar signal processing. Two-dimensional Fourier transformation is carried out on two-dimensional time domain echo data acquired by the curve trajectory squinted SAR, and the two-dimensional time domain echo data are transformed into a two-dimensional frequency domain; after the two-dimensional frequency domain signals are multiplied by a reference function and specially Stolt mapping, the signals are transformed into a range Doppler domain by using inverse Fourier transformation in the range direction; range migration correction, azimuth compression and azimuth offset correction are carried out in the range Doppler domain; inverse Fourier transformation is carried out in the azimuth direction, the signals are transformed into two-dimensional time domain, and finally, imaging results are obtained. The application utilizes a specially designed Stolt mapping to avoid complex additional range migration caused by a traditional Stolt mapping, and then range migration correction and azimuth compression are sequentially carried out in the range Doppler domain to solve the problem that equivalent radar speed and other parameters cannot change with distance.

This invention provides a method and apparatus for recovering single-bit SAR signals based on sparsity assessment, belonging to the field of signal processing technology. The method includes: performing range migration correction on the single-bit quantized spaceborne SAR echo signal to be recovered, obtaining a two-dimensional linear frequency modulated (LFM) signal; dividing the target imaging region into spatial grids, and establishing a SAR imaging observation model based on the LFM signal within the grid points; establishing a sparsity optimization model based on the SAR imaging observation model, and iteratively updating the sparsity optimization model to obtain an optimal estimate of the scene sparsity; and recovering the corrected echo signal based on the optimal estimate to obtain a reconstructed echo signal that meets quality standards. This solution can solve the problem of difficulty in obtaining target scene sparsity during imaging processing.

The present invention discloses a forward-looking three-dimensional imaging technology for an airborne radar based on a two-dimensional super-resolution algorithm. A planar array antenna is used to receive scattered echoes from targets in the area in front of the carrier aircraft. After pulse compression and range migration correction are performed, the observation area is gridded and azimuth-elevation echo modeling is completed. For each two-dimensional snapshot data, a weighted least squares criterion is used to construct a cost function with weights. The parameters are iteratively updated until the estimation results converge to obtain a single azimuth-elevation super-resolution spectrum. Two-dimensional spectrum incoherent accumulation is performed on several super-resolution spectra of the same range gate to obtain three-dimensional super-resolution data in polar coordinates. Finally, the polar coordinate data is transformed into a spatial rectangular coordinate system and plotted to obtain forward-looking three-dimensional super-resolution imaging. The present invention only requires a single snapshot to complete azimuth-elevation two-dimensional super-resolution, which overcomes the disadvantage that a moving platform cannot accumulate a large number of snapshots for the same observation target while further improving the imaging resolution.

The application relates to a large downward-viewing-angle unmanned aerial vehicle (UAV) SAR motion compensation method based on an improved PGA algorithm, which comprises the following steps: performing inertial navigation coarse compensation and distance compression on echo signals to obtain first echo signals; performing non-space-variant phase error estimation on the first echo signals to obtain Doppler frequency modulation; performing non-space-variant range migration correction and coarse compensation of phase error on radar data according to the non-space-variant phase error to obtain a non-space-variant phase function after coarse compensation; estimating space-variant phase error, performing compensation processing according to the space-variant phase error, and obtaining a compensated space-variant phase function; splicing the compensated space-variant phase functions of all sub-apertures to obtain a full-aperture phase error; removing an overall linear component in the full-aperture phase error through linear fitting to obtain radar data after motion compensation; and performing imaging on the radar data after motion compensation by using a UAV SAR imaging algorithm to obtain imaging results. The application can accurately correct phase errors caused by distance space variation.

This invention discloses a method, system, and apparatus for processing ultra-high-speed target echo signals, belonging to the field of signal processing technology. The method includes: dividing the possible radial motion velocity range of a high-speed target into multiple velocity levels; constructing a corresponding reference signal for each velocity level; multiplying the range-dimensional spectrum of the target echo from the intra-pulse motion model with the conjugate of the reference signal to obtain a frequency-domain pulse compression result; matching the reference signal with the echo signal; constructing a migrating phase compensation function; performing slow-time phase compensation on the migrating phase-compensated echo signal; performing range-dimensional IFFT processing on the echo signal; and performing MTD processing on the output signal of the range-dimensional IFFT. This invention effectively solves the range migration problem of high-speed target echoes and the mismatch filtering caused by echo scale transformation, thereby more accurately estimating the target velocity and range information.

The invention discloses a radar detection waveform design and processing method with robust range migration, belongs to the technical field of radar target detection, and aims at extracting target key prior information through echo signal analysis and then designing a transmitted signal waveform in a targeted manner through the prior information. According to the method, the design logic of firstly sensing the target state and then customizing the waveform is adopted, so that the transmitted signal is highly matched with the motion characteristic of the target, a more accurate time delay reference is provided for subsequent range migration correction, migration offset caused by mismatching of the waveform and the target is reduced from the transmitting end, and a high-quality signal foundation is laid for subsequent correction.

The application provides a SAR deception jamming method of mixed domain efficient track deviation compensation, comprising the following steps: after a SAR radar enters a detection range of a jammer, relevant parameters of the SAR radar are acquired, and a jammer deception template is constructed according to false electromagnetic features generated in a SAR image by jamming; azimuth focusing and range migration compensation calculation are performed on the jammer deception template in an azimuth frequency domain, and then inverse Fourier transform in the azimuth direction is performed to obtain an initialization template; after the SAR radar enters a jamming area, real-time modulation is performed, track deviation compensation is performed on the initialization template after coupling term decomposition in the azimuth time domain, and a real-time SAR system correlation filter is constructed in the azimuth time domain pulse by pulse; the real-time SAR system correlation filter and the jammer correlation filter are multiplied in a range frequency domain to obtain a non-linear track jamming frequency domain response function, and convolution operation is performed on the non-linear track SAR deception jamming signal obtained after the SAR signal intercepted to obtain a non-linear track SAR deception jamming signal.

The invention provides a high-speed maneuvering target segment coherent accumulation detection method based on a sub-segment signal distance-azimuth coupling relation. The method comprises the following steps: carrying out fast Fourier transform on echo signals after pulse compression in a fast time domain; performing segmentation processing on the echo signal after the fast Fourier transform in a slow time domain; searching a high-order motion parameter of the target, constructing a high-order phase correction function, and eliminating the influence of the high-order motion parameter; compensating Doppler ambiguity and inter-subsegment residual distance migration; and performing inverse fast Fourier transform on the corrected and compensated echo signal in a fast time domain to complete joint accumulation of a plurality of sub-segment signals so as to obtain a result after distance-Doppler domain coherent accumulation processing of the high-speed maneuvering target. The problems that an existing method is too high in operation complexity, serious in integral loss, limited in application range and the like when used for detecting the high-speed maneuvering target are solved, and the high-maneuvering target with complex arbitrary-order range migration and Doppler migration can be effectively detected.

The present application belongs to the technical field of radar moving target imaging, and particularly relates to a terahertz circular SAR moving target parameter estimation and refocusing method. The present application reduces two-dimensional coupling in the range and azimuth by dividing sub-apertures, performs range compression on the echo under each sub-aperture by performing inverse Fourier transform in the range direction and after slant correction, estimates the Doppler center by using the spectral peak measurement method and combining the shadow position, estimates the Doppler frequency by using the fractional Fourier transform, estimates the along-track speed and radial speed information of the moving target according to the estimated results, constructs a first-order and second-order phase compensation function, corrects the azimuth direction offset, partial defocusing and additional range migration, and compensates the residual quadratic and higher-order phase by using the phase gradient autofocus algorithm. The refocusing effect of the moving target in the simulation data verifies the effectiveness of the present method.