31 results about "Azimuth compression" 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 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.

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 SAR image self-focusing distortion correction method and device, and belongs to the technical field of synthetic aperture radars. The method comprises the following steps: carrying out distance blocking and orientation sub-aperture division on a defocused SAR image, selecting a sample, and carrying out orientation decompression to a phase historical domain; performing azimuth dechirp processing on the sub-aperture data in each distance sub-block, and estimating a phase error through a standard PGA algorithm; after splicing sub-aperture phase errors and removing an overall linear phase, performing phase compensation and azimuth compression to obtain a focused image; and for azimuth distortion caused by residual linear phase of the compensated image, extracting a phase error linear term coefficient through a sliding window, deducing an azimuth shift distance in combination with Fourier transform time shift characteristics, and finally performing shift correction by adopting sinc interpolation. According to the method, the image focusing quality is improved, and meanwhile, the ground feature continuity and the image resolution are kept.

The invention discloses a multi-channel spaceborne SAR (Synthetic Aperture Radar) high-squint sliding bunching imaging method, which solves the problems of signal time frequency inconsistency and serious imaging Doppler parameter coupling and space-variant in multi-channel spaceborne SAR high-squint sliding bunching mode imaging, and makes up the limitation of the prior art. Specifically, the method comprises the following five steps: step 1, constructing a slope distance model and an echo signal model of a multi-channel spaceborne SAR high squint sliding bunching signal; step 2, constructing a time-frequency characteristic parameter model of the multichannel spaceborne SAR high squint sliding bunching signal; step 3, carrying out azimuth preprocessing based on walking removal and spectrum reconstruction on the signal, and recovering to an equivalent single-channel signal; step 4, performing distance direction CS processing, and completing distance migration correction and distance compression; and step 5, carrying out azimuth NCS processing to complete azimuth compression.

This application relates to the field of space imaging technology and provides a method for decoupling translational and rotational motion in space-based microwave imaging of space targets based on parameter estimation. The method first uses adjacent cross-correlation and self-focusing methods to perform preliminary compensation for the translational motion components of the microwave imaging echo data. Then, using the first-order translational motion parameters fitted by the former as initial values ​​and minimizing the image entropy of the echo data as the cost function, it combines Keystone transform to optimize and compensate for the translational linear phase components. Next, it uses Keystone transform to compensate for the spatially varied range cell migration caused by the rotational motion components. Finally, it performs a second compensation for the residual translational motion components, obtaining echo data after almost complete compensation of the translational and rotational MTRC. By performing spatially varied phase error compensation and azimuth compression on this data, the imaging result of the space target can be obtained. This method achieves a balance between the efficiency and accuracy of parameter estimation, effectively improving imaging quality.

The present invention provides a high-resolution imaging algorithm for high-squint SAR (SAR) based on a deep unfolding network: Step 1: Constructing a high-squint SAR echo signal observation model, and determining, based on the RD algorithm, that the imaging matrices required for learning by the imaging network are quadratic range compression, a cubic phase compensation matrix H2, and an azimuth compression matrix H3; Step 2: Constructing a corresponding high-squint SAR imaging network based on the learning parameters H2, H3, and other parameters determined in Step 1, and simultaneously constructing a corresponding high-squint SAR echo dataset. By deeply unfolding the ISTA algorithm into a network form, a more accurate imaging matrix is ​​obtained compared to traditional imaging algorithms, thereby improving imaging accuracy and focusing effects. This imaging method can perform high-resolution two-dimensional imaging of a target without constructing a complex compensation function, effectively suppressing sidelobes, improving imaging accuracy and computational efficiency, and achieving better imaging quality than other imaging algorithms under conditions of increased squint angles, thus meeting SAR imaging requirements under high-squint conditions.

This invention relates to the field of radar imaging technology, and proposes a system and method for detecting local surface defects in field equipment based on a robotic arm. The system includes: a robotic arm unit with a SAR transceiver antenna mounted at its end, which transmits electromagnetic signals to the surface of the field equipment to be inspected and receives echo signals; a motion controller connected to the robotic arm unit, which controls the movement trajectory of the robotic arm; and an industrial control computer, which has a built-in SAR imaging data processing module and a path optimization module. The industrial control computer is electrically connected to the motion controller and the SAR transceiver antenna, respectively, driving the robotic arm unit to move according to the planned sampling trajectory, and simultaneously controlling the signal transmission and reception timing of the SAR transceiver antenna; the SAR imaging data processing module performs range compression, azimuth compression, and two-dimensional inverse Fourier transform processing on the received echo signals to generate SAR images characterizing the surface and internal defects of the equipment. This invention achieves full automation of the field equipment defect detection process.

The application provides a terahertz SAR high-efficiency self-focusing imaging method and system based on RB-PCA, comprising: obtaining original echo signal data and performing pretreatment; performing distance block in the distance direction on the pretreated echo signal data to obtain a plurality of distance blocks, performing sub-aperture segmentation in the distance block for each distance block to obtain a plurality of sub-aperture signal data; performing desquamation processing on each sub-aperture signal data to obtain desquamation signal data; performing PCA processing on the desquamation signal data and selecting a characteristic vector with the largest characteristic value as a target characteristic vector; obtaining each sub-aperture phase error gradient estimation value through adaptive PGA estimation on the target characteristic vector; obtaining two-dimensional space-varying phase errors of each distance block through global splicing and fusion on each sub-aperture phase error gradient estimation value; and performing phase compensation and azimuth compression on the pretreated echo signal data based on the two-dimensional space-varying phase errors to obtain focused imaging results.

The invention discloses a space target ISAR imaging and calibration integration method based on translation and rotation parameter joint estimation, and relates to the technical field of remote sensing and radar imaging. The method aims to solve the problems that in existing space target ISAR imaging, rotation parameter estimation is affected by motion compensation, and space target scattering points are likely to walk over a distance unit under long-time accumulation. According to the method, distance compression is performed on echoes acquired by a ground-based radar, generalized Radon Fourier transform is performed after a one-dimensional distance image sequence is acquired, and then phase coefficients of all orders of echo signals are estimated; calculating a module value and a compensation signal of an effective rotation angular velocity of the spatial uniform-speed rotation target by using the estimated value; carrying out translation compensation on the echo signal by using the compensation signal, converting the compensated echo signal from a Cartesian coordinate system to a polar coordinate system by using the effective rotation angular velocity, and carrying out interpolation; and performing distance and orientation compression on the interpolation result to obtain an imaging result, and completing calibration according to the effective rotation angular velocity to realize integration of space target ISAR imaging and calibration.

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.

This invention discloses a MIMO-SAR echo separation method based on image post-processing in complex detection scenarios, belonging to the field of signal processing. The method includes: designing the MIMO-SAR transmit waveform and collecting echo signals using a multi-channel elevation system; performing range and azimuth compression sequentially on the received data from the multi-channel elevation system using a classic imaging algorithm to complete imaging processing; constructing an elevation-dimensional spatial snapshot signal based on the processed multi-channel data and estimating the sample covariance matrix using range samples; performing eigenvalue decomposition on the covariance matrix to estimate the number of sources in the spatial domain; estimating the angle of arrival (AHA) of the sources using the MUSIC algorithm, given a fixed number of sources; calculating the optimal weight vector based on the least squares criterion and processing the spatial snapshot to suppress interference signals in the echo, thus solving the echo separation problem in MIMO-SAR. This method can effectively mitigate the impact of AHA mismatch caused by terrain undulations on echo separation performance and improve the imaging performance of the MIMO-SAR system in complex detection scenarios.

The invention discloses an integrated imaging method, system and equipment for translation compensation and azimuth dimension compression of a space orbit target by a spaceborne radar and a medium, and relates to the technical field of microwave remote sensing. The objective of the invention is to solve the problems that in the process of space orbit target imaging by a spaceborne radar, the similarity between echo envelopes is reduced, the echo envelopes may be submerged by noise due to the low echo signal-to-noise ratio, translation compensation is difficult to carry out, and a clear image is difficult to obtain after azimuth dimension compression processing. The method comprises the following steps: establishing a relationship between a translation component coefficient and a transformation parameter of a space orbit target relative to a radar satellite; carrying out fast and slow time fractional Fourier transform on the echo signal of the space orbit target based on the transformation parameter to obtain a transformation spectrum; and searching the transformation parameters by adopting a PSO optimization algorithm, so that the image entropy of the transformation spectrum is minimum, and space orbit target imaging is completed.

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.

The present invention provides a multi-beam SAR wide-swath imaging and moving target detection method, including: acquiring initial APC waveform echoes of a plurality of to-be-imaged range sub-bands containing moving targets; converting each initial APC waveform echo into the range-Doppler domain and separating them using azimuth DBF technology; demodulating each separated initial APC waveform echo and performing pulse compression to obtain a plurality of intermediate APC waveform echoes; obtaining a plurality of target APC waveform echoes by processing each intermediate APC waveform echo using elevation DBF technology; achieving azimuth focusing by performing azimuth compression on each target APC waveform echo to obtain an initial sub-region image; performing space-time adaptive processing in the image domain on each initial sub-region image to obtain a plurality of intermediate sub-region images after moving target detection; and stitching the plurality of intermediate sub-region images after moving target detection to obtain a wide-swath SAR image containing a plurality of moving targets.

A method for automatically selecting time points for multi-target ISAR imaging includes the following steps: S1: performing pulse compression on a broadband echo sequence for multi-target imaging; S2: performing range image averaging and calculating the waveform entropy of the average range image; S3: taking the time corresponding to the range image with the maximum waveform entropy as the time reference and performing a Keystone transform; S4: performing azimuth compression on the range image sequence to obtain a multi-target range-Doppler two-dimensional image; S5: after target separation on the range-Doppler plane, performing motion compensation and R-D imaging processing on each target to obtain an ISAR image of each target. By calculating the waveform entropy of the average range image, the present invention can automatically select the time point at which the multi-target overlap is minimized, thereby improving computational efficiency. The automatically selected time point exhibits the best separability of target echoes, thereby improving imaging efficiency.

The invention discloses a vehicle-mounted SAR (Synthetic Aperture Radar) real-time imaging method based on an improved distance Doppler algorithm, and relates to a close-range and large-squint-angle imaging algorithm in a vehicle-mounted scene. The method comprises the following steps: dividing a full aperture into sub-apertures; compensating a residual video phase term; doppler frequency shift items caused by fast time are eliminated; carrying out high-order Taylor expansion on the distance and azimuth coupling terms of the signal, constructing a distance migration filter based on the second term of Taylor expansion to carry out distance migration correction, and constructing a secondary distance compression filter based on the third term and higher-order terms of Taylor expansion to carry out secondary distance compression; azimuth compression processing is carried out after distance dimension focusing, and two-dimensional focusing is completed; and after all the sub-apertures are focused, splicing the sub-aperture images to obtain a full-aperture image. According to the invention, high-order Taylor expansion is carried out on the distance and azimuth coupling term, so that the coupling term is accurately compensated, and high-precision near-field imaging can be completed while the advantage of the classical RDA imaging speed is kept.

The application discloses a kind of small SAR data processing method and system based on PCIe RDMA, it is related to radar signal and information processing technical field, comprising the following steps: S1, data preprocessing: the original echo data received by radar is preprocessed;S2, range compression: the original echo data after preprocessing is compressed in range;S3, azimuth compression: the original echo data compressed in range is compressed in azimuth, and the SAR image of target area is obtained;S4, image post-processing: SAR image is post-processed, and post-processing includes geometric correction, radiation correction and image enhancement.The application adopts the above-mentioned small SAR data processing method and system based on PCIe RDMA, eliminates the data copy overhead of CPU participation in traditional communication model, realizes the direct access of cross-node memory after the interconnection of multiple hosts through PCIe, significantly reduces data transmission delay, and improves system bandwidth.

The application discloses a kind of based on physical consistency modeling multiple scattering SAR imaging simulation method, system, equipment and medium, including the following steps: constructing the three-dimensional electromagnetic model of target;Geometric model under the condition of transmitting-receiving co-located SAR operating mode is constructed by light ray tracing;Using high-frequency electromagnetic scattering algorithm based on ray tracing, considering first-order, second-order and higher order multiple scattering path, the superposition and amplitude modulation of each order scattering contribution are carried out, the scattering field distribution of target under far-field condition is calculated, and the far-field scattering field is obtained;Total far-field scattering field is mapped by space propagation, and the far-field scattering result is mapped as radar platform near-field echo signal;Echo signal amplitude is corrected, and two-dimensional SAR near-field echo matrix is obtained;SAR imaging processing is carried out, and SAR imaging processing includes range compression, range migration correction RCM and azimuth compression.The application improves the fidelity and accuracy of SAR imaging simulation under complex target scene.

The application relates to the technical field of remote sensing and radar imaging, and relates to a space target ISAR imaging and scaling integrated method based on a translation-rotation parameter joint estimation.The application is used to solve the problem that the existing space target ISAR imaging is affected by motion compensation, and the scattering points of a space target are prone to moving across distance units in a long-time accumulation.The application performs distance compression on echo obtained by a ground-based radar, performs generalized Radon Fourier transformation on a one-dimensional distance image sequence, and further estimates phase coefficients of the echo signal; the effective rotation angular velocity module value of a space uniform rotation target and a compensation signal are calculated by using the estimated value; the echo signal is subjected to translation compensation by using the compensation signal, the compensated echo signal is converted from a Cartesian coordinate system to a polar coordinate system by using the effective rotation angular velocity, and interpolation is performed; the imaging result is obtained by performing distance and azimuth compression on the interpolation result, scaling is completed according to the effective rotation angular velocity, and the space target ISAR imaging and scaling integration are realized.

The present invention discloses a method for detecting indoor moving targets using an unmanned aerial vehicle (UAV) through-the-wall radar. The method comprises: proposing a moving target detection method based on a Doppler frequency modulation profile and range-gated filtering. The imaging results of moving targets are defocused and easily submerged in strong stationary clutter, which reduces the moving target detection rate. To address this problem, the present invention analyzes the Doppler frequency modulation characteristics of stationary clutter and moving targets. Then, the range migration of the target echo is corrected in the range Doppler domain through sinc interpolation. Next, a fractional-order Fourier transform is applied to estimate the Doppler frequency modulation of each range gate of the echo. The estimated frequency modulation value is compared with the theoretical frequency modulation value of the stationary target. Based on the difference in Doppler frequency modulation, a range-gated filter is designed to suppress clutter generated by walls and stationary objects. Finally, an azimuth compression filter is constructed to achieve focused imaging of moving targets. Simulation and field experiments verify the feasibility and effectiveness of the proposed method.

The invention discloses an improved CS imaging method for a high-orbit synthetic aperture radar. According to the method, firstly, a high-orbit SAR polynomial approximation equivalent slope distance model is established; 2, performing six-order Taylor series expansion on the slant range process; step 3, carrying out two-dimensional Fourier transform on the high-orbit SAR signal echo model; 4, solving an azimuth stationary phase point by using a series inversion method; 5, the two-dimensional frequency spectrum is organized through power series expansion; 6, improving a CS algorithm, and carrying out three-time phase compensation; step 7, carrying out a distance-Doppler domain Chirp Scaling operation; 8, distance compression is carried out; ninthly, consistent distance migration correction is carried out; tenth, carrying out azimuth compression; and eleventhly, carrying out azimuth phase compensation. Compared with a traditional high-orbit SAR fourth-order slope distance model, the method can meet the higher slope distance error precision requirement.

The invention discloses an Omega-K and FNCS combined high-speed large-squint curve track SAR imaging method. The method comprises the steps of expanding an instantaneous slant range history to five orders through Taylor series to obtain a polynomial slant range model; linear range walk correction, range pulse pressure and acceleration de-chirp preprocessing are carried out in an echo signal range wavenumber domain; blocking the two-dimensional time domain signal distance, introducing a reference function into the two-dimensional wave number domain of a sub-block, and carrying out distance unit migration correction by using improved Stolt mapping; introducing an alignment function to the signal after range unit migration correction, and realizing range focusing by using two-dimensional IFFT (Inverse Fast Fourier Transform); during azimuth processing, a five-order perturbation function is introduced into an azimuth time domain, a five-order NCS function is introduced into an azimuth frequency domain, unified azimuth compression is performed in the azimuth time domain, and finally a two-dimensional SAR image is obtained by utilizing azimuth FFT. The method can be directly applied to a high-speed large-squint SAR system under a curve track, and high-precision curve track SAR imaging can be realized under a high-speed large-squint view angle scene.

The invention discloses a CLEAN single-channel external radiation source bistatic radar direct wave suppression method based on principal component analysis, and belongs to the field of signal processing. After echo channel signals are acquired, the distance of each frame of signal is compressed, and the distance offset and Doppler broadening are compensated according to an equivalent distance model; the method comprises the following steps: firstly, carrying out azimuth compression on a distance Doppler domain, then carrying out accumulation average processing on each frame in the distance Doppler domain after azimuth compression, then carrying out PCA principal component analysis to reconstruct a complete direct wave as a reference interference signal of a single-channel echo signal, and carrying out CLEAN correlation coefficient calculation in the distance Doppler domain to complete suppression and cancellation of the direct wave in a single channel. According to the method, strong direct wave interference in a satellite-borne passive radar system under single-channel receiving is suppressed, so that a target with relatively weak energy is not easily covered by strong direct waves or other background interference, and a foundation is laid for subsequent target detection and tracking processing.

The present invention provides a two-dimensional ambiguity suppression method for phase-coded multi-beam SAR imaging. The method includes: obtaining initial APC waveform echoes of multiple range sub-bands to be imaged; padding zeros at intervals along the azimuth direction for the multiple initial APC waveform echoes to obtain multiple up-sampled echoes of the initial APC waveforms; separating the multiple up-sampled echoes by using azimuth DBF technology to obtain multiple intermediate APC waveform echoes; demodulating the multiple intermediate APC waveform echoes based on the coding form and the range ambiguity number of the range sub-bands to be imaged; performing pulse compression processing on the demodulated multiple intermediate APC waveform echoes and processing them by using elevation DBF technology to obtain multiple target APC waveform echoes; obtaining an unambiguous sub-region image by performing azimuth compression on any one of the target APC waveform echoes; and splicing the sub-region images of the multiple range sub-bands to be imaged to obtain an unambiguous wide-swath SAR image. This method converts range ambiguity suppression into azimuth ambiguity suppression, improves the two-dimensional ambiguity suppression ability, and increases the mapping swath width.

The invention discloses an imaging processing method for a strip mode and a TOPS mode of a high-resolution wide-width satellite-borne SAR (Synthetic Aperture Radar) radar, which comprises the following steps of: performing range time domain resampling, phase compensation and range-direction fast Fourier transform processing on echo data subjected to range pulse compression in a range direction; discrete sampling of two-dimensional Fourier transform of the reflection function of the target scene is obtained; performing polar coordinate format conversion through distance and azimuth one-dimensional resampling, and converting echo data sampling points into data on a rectangular grid; carrying out azimuth fast Fourier transform processing on the signal after azimuth resampling, transforming the signal to a frequency domain, multiplying the frequency domain by a reference function, and finally, carrying out inverse Fourier transform to return to a time domain to complete azimuth compression; and performing two-dimensional accurate focusing on the image through range-direction fast inverse Fourier transform, and outputting a focused image. According to the invention, the problem of efficient and accurate imaging processing of satellite-borne SAR stripe mode and TOPS mode data is effectively solved.

The present invention discloses a spaceborne polar ice radar three-dimensional imaging method. The method first acquires antenna echo signals and superimposes signals received by the same antenna. The superimposed image is then subjected to secondary range compression and center point range migration correction. Complementary range migration correction is further performed. Azimuth compression is performed through phase multiplication to obtain a two-dimensional under-ice image. After corresponding additional phase multiplication, the two-dimensional under-ice image is subjected to cross-track range migration correction to ensure that the range signals of all antennas are consistent with the center antenna. The corrected two-dimensional images are written into a three-dimensional array to obtain a three-dimensional image. The three-dimensional image is multiplied by a reference function in the cross-track direction, and the additional phase in the two-dimensional image is compensated in the cross-track direction. Finally, the three-dimensional image is Fourier transformed in the cross-track direction to obtain a three-dimensional focused image. The method has high computational efficiency and can obtain richer under-ice data through compressed imaging in the third dimension.

The application relates to an airborne SAR moving target imaging method based on Doppler parameter estimation, and aims to solve the problem that a traditional RD algorithm is not applicable to airborne SAR moving target imaging. The process is as follows: 1. the Doppler center frequency and the Doppler frequency modulation slope of a target are derived; 2. a distance frequency domain signal is obtained; 3. a distance compression function is constructed to obtain distance compressed echo data; 4. an azimuth compression function is constructed to obtain azimuth compressed data; 5. a particle swarm optimization algorithm is adopted to obtain the target Doppler center frequency and the Doppler frequency modulation slope corresponding to the minimum entropy value; 6. a distance migration correction function is constructed to obtain two-dimensional frequency domain data after distance migration correction; 7. a distance matching function is constructed to obtain distance compressed azimuth frequency domain data; 8. an azimuth matching function is constructed to obtain two-dimensional time domain data, and imaging is completed. The application is used in the field of airborne SAR moving target imaging.

The invention discloses an embedded edge AI acceleration radar signal processing system and method, and relates to the technical field of radar signal processing and embedded artificial intelligence. The embedded edge AI acceleration radar signal processing system comprises a power supply module, a radio frequency subsystem and a signal processing subsystem, wherein the power supply module supplies power to the radio frequency subsystem and the signal processing subsystem, and the signal processing subsystem comprises an AI chip and an FPGA chip which are interconnected through an SRIO protocol. The embedded edge AI acceleration radar signal processing method comprises the steps that a radio frequency subsystem receives a radio frequency signal and sends the radio frequency signal to a signal processing subsystem; the FPGA chip collects data and transmits the data to the AI chip; the AI chip executes a real-time imaging algorithm including complementary RCMC, consistent RCMC, phase compensation and azimuth compression, and meanwhile, the FPGA performs frequency conversion, motion compensation and FFT operation in real time; the AI chip executes a target recognition algorithm on the SAR image; and the signal processing subsystem outputs and stores a target identification result. The system power consumption can be effectively reduced, and the delay is reduced.