41 results about "Phase error compensation" patented technology

The invention discloses a space-variant self-focusing imaging method for a missile-borne synthetic aperture radar sea surface moving target. The method comprises the following steps: acquiring a radar fundamental frequency echo signal; performing range pulse pressure and range migration correction on the radar fundamental frequency echo signal to obtain a correction signal, and further obtaining a coarse focusing radar image; extracting a single defocusing target image in the coarse focusing radar image, and inverting the single defocusing target image to an echo data domain to obtain data of single target energy; performing correction to obtain data after correction of the residual range walk; selecting a part of distance units from the data after the residual range walk is corrected, performing Doppler frequency modulation rate estimation on the selected part of distance units by adopting fractional Fourier transform, fitting the estimated Doppler frequency modulation rate by adopting a space-variant phase error model, and constructing a space-variant phase error compensation function of the target; and compensating the data after the correction of the residual range walk, and imaging. According to the invention, the refocusing effect of the moving ship target can be improved.

The invention relates to the technical field of intelligent signal processing, in particular to an unmanned aerial vehicle cluster intelligent beamforming method and system, and the method comprises the following steps: obtaining unmanned aerial vehicle node positions, antenna deviation and synchronization errors, analyzing the influence of quantization precision on beamforming, extracting low-precision waveform features, recognizing the amplitude-phase error compensation amount, and optimizing the anti-interference performance. Phase constraints are extracted and optimized, the consistency of the beam and the expected direction is compared, parameters are adjusted to obtain an adjustment instruction set, and a beam forming maintaining state label is output. According to the method, position information, pointing deviation and synchronization errors are analyzed through joint modeling, amplitude-phase feature extraction precision is improved, interference and echo separation capability is enhanced, control robustness is improved, discrete phase constraint and alternating direction optimization are introduced, control vector solution and convergence are accelerated, and direction errors are dynamically adjusted. A retention label is generated through convergence trend analysis, beam consistency and anti-interference performance are enhanced, and high-precision stable control is realized in a complex change scene.

The invention relates to an underwater acoustic image reconstruction method based on angle error compensation, which comprises the following steps of: (1) calculating space coordinate information and a two-way slant range course of a transmitting array element and a receiving array element for each subsystem consisting of the receiving array element and the transmitting array element; (2) calculating a two-way slant range course after phase center approximation; (3) calculating a system function of a distance-Doppler domain; (4) calculating a Doppler phase error; (5) dividing the data into # imgabs0 data blocks which are not overlapped with one another, and compensating micro-range migration errors caused by range errors; (6) obtaining a signal after distance delay error compensation; (7) performing differential range migration correction processing, range pulse compression, secondary range pulse compression and consistent range migration correction processing; (8) carrying out azimuth focusing processing, residual phase error compensation operation and azimuth walking correction processing; and (9) performing coherent fusion processing and inverse Fourier transform to obtain a final high-resolution image. According to the method, the image can be quickly reconstructed, and the real-time processing requirement can be met.

The invention discloses a multi-channel leaky coaxial cable fault positioning system and method, and belongs to the technical field of rail transit leaky coaxial cable fault positioning and monitoring. The system comprises a modulation signal generator, a circulator, an SPTD module, an FPGA signal processor and an upper computer. The system only needs to install a monitoring device at one end of the leaky coaxial cable, and is convenient to implement. The ZYNQ control panel is used for controlling IO signals, so that the SPTD switch is controlled to realize switching of monitoring channels, and multi-channel fault detection and positioning are realized; the unattended operation is realized, the detection and positioning cost is effectively reduced, and the detection efficiency is improved. According to the method, by introducing the phase error compensation function of the transmitting signal and the phase error compensation function of the echo signal, the phase compensation of the frequency mixing signal is realized, so that the phase error of the fault detection signal is reduced, the detection precision is improved, and the accuracy of fault judgment, fault point positioning and fault type judgment is effectively improved.

A calibration system and related methods for optical phased array chips. The calibration system includes an adjustable mount module, an infrared microscopic observation module, an arrayed driver module, a two-dimensional laser beam scanning module, a photoelectric conversion module and an upper computer, and utilizes computer-vision-enabled positioning and phase error compensation algorithms as software components. Collimated laser is emitted from the target beamforming angle and aimed at the emission aperture of the chip, and is subsequently sampled by the array elements in a reversed injection manner. Based on the reciprocity of light propagation, by maximizing the power reversely output from the bus waveguide of the optical phased array chip, beamforming at the target angle is achieved supported by software implementations of optimization algorithms. The system and related methods are readily achievable, highly automated, and offers fast and batch calibration with relatively low expenses, good flexibility and long-term compatibility.

The invention relates to the technical field of frequency modulation laser interference ranging, in particular to a frequency modulation laser interference ranging nonlinear phase error compensation system and method, which can realize effective compensation of intermediate frequency signal phase errors and improve ranging precision under the condition that the algorithm complexity is not greatly improved. According to the system, the nonlinear phase error of the intermediate frequency signals of the reference branch and the measurement branch is accurately compensated, so that the phase error caused by frequency modulation nonlinearity is remarkably reduced, and the overall ranging precision of the laser interference ranging system is further improved. Intermediate frequency signal nonlinear phase error compensation is adopted, the nonlinear phase error is effectively compensated under the condition that hardware consumption is not greatly improved, and finally the ranging precision of the system is improved.

The invention discloses a unified beam control mode back projection SAR imaging post-processing method, and relates to the technical field of radar signal processing, and the method comprises the steps: carrying out the range pulse compression and side lobe suppression of original echo data; then establishing a minimum error imaging grid and performing coordinate system conversion; constructing a uniform spectrum compression function, and designing an azimuth time domain windowing function according to the relative position of the beam pointing and the grid point; integrating a unified frequency spectrum compression function and an azimuth time domain windowing function in a back projection imaging process to realize focusing reconstruction of a preprocessed signal; and finally, a high-quality post-processing image is obtained through phase error compensation. The method effectively improves the imaging precision and efficiency, and is suitable for various beam control modes.

The invention discloses a method and a device for analyzing and correcting influence of phase errors between sub-bands of step-frequency ultra-wideband SAR (Synthetic Aperture Radar) data, and belongs to the technical field of synthetic aperture radar signal processing. The method comprises the following steps: carrying out amplitude error estimation and compensation on each sub-band echo signal; preliminarily estimating a phase error by using the partial overlapping characteristic of the sub-band spectrum; performing distance compression on each sub-band signal; establishing an optimization model based on a maximum norm, and solving an accurate phase error by taking the preliminarily estimated phase error as an iteration initial value; carrying out sub-band splicing and distance resolution compression on the sub-band signals after phase error compensation; and finally, a corrected SAR image is obtained through a CS imaging algorithm. According to the method, extra calibration signals are not needed, high-precision phase error correction can be achieved only based on echo data, the calculation efficiency is high, and the method is suitable for a high-resolution SF-SAR system.

The invention relates to an SAR photoelectric processor phase error compensation method based on a Zernike polynomial, and the method comprises the steps: obtaining an SAR photoelectric processor to be subjected to phase error compensation, and employing the Zernike polynomial to express the modulation phase of a spatial light modulator in the SAR photoelectric processor; respectively calculating two-dimensional frequency domain phases of an ideal SAR echo signal and a non-ideal SAR echo signal of the SAR photoelectric processor, determining a focusing phase error, fitting the focusing phase error by adopting a Zernike polynomial, and evaluating focusing phase error (parameter) estimation performance; a plurality of Zernike coefficients are randomly generated for a Zernike polynomial, optimization of the Zernike coefficients is carried out by adopting a genetic algorithm, and the quality of the SAR image is used as a fitness value of the genetic algorithm until the Zernike coefficients meeting optimization conditions of the genetic algorithm are obtained and used for prediction of a modulation phase. Compared with the prior art, the two-dimensional frequency domain phase error can be effectively corrected, and a theoretical foundation is laid for an automatic focusing algorithm special for SAR optical processing.

The present invention discloses a zero-IF receiving array IQ imbalance beam-level compensation method, comprising: obtaining a radio frequency signal received by each array element; obtaining M intermediate frequency analog signals; obtaining M baseband analog in-phase signals and M baseband analog quadrature signals; performing A / D sampling on the M baseband analog in-phase signals and the M baseband analog quadrature signals respectively to obtain M baseband digital complex signals; obtaining M receiving channel amplitude and phase error compensation values; performing channel amplitude and phase error compensation and beam weighting compensation on the M baseband digital complex signals of the digital array, and summing the values to obtain a beamformed output complex signal; and utilizing the circular characteristics of the received baseband digital complex signals to estimate and compensate for the IQ imbalance error after beamforming to obtain a final baseband digital complex signal of the digital array. The present invention has the advantages of providing a multi-channel IQ imbalance compensation method that does not require channel-by-channel estimation and compensation for IQ imbalance errors and protects the circular characteristics of communication signals from being destroyed.

The invention provides a time synchronization method for space laser communication, which relates to the technical field of laser communication, and comprises the following steps: encoding a time signal, modulating a frequency signal, compounding into an original communication signal, transmitting the original communication signal from a ground end to a space end, and receiving the signal by the space end after the signal is transmitted in the space; the space end demodulates the received communication signal, and performs synchronization processing on the obtained received time signal through a time synchronization algorithm; and the space end demodulates the received communication signal, performs phase error compensation on the obtained frequency signal, and composites the synchronized time signal and the frequency signal after phase error compensation through a multiplexing module to complete frequency time synchronization of the communication signal.

The application relates to a kind of multi-resident observation 2D super-resolution ISAR imaging methods based on fast IWF, comprising S1 modeling 2D super-resolution ISAR imaging of multi-resident observation signal;S2 initialize the accuracy of signal in fast IWF method, and set the maximum iteration number of fast IWF method;S3 calculate the LC decomposition factor of the inverse matrix G ‑1 of auxiliary observation covariance matrix;S4 estimate target rotation speed, for compensating distance space variable phase error, and obtain error compensation after observation signal;S5 based on the LC decomposition factor of G ‑1 And distance space variable phase error compensation after observation signal, signal estimation value is calculated using 2D-FFT, and the accuracy of signal is updated;S6 repeat steps S3-S5 to carry out cyclic iteration, stop after reaching convergence, obtain super-resolution ISAR image based on signal estimation value and realize transverse calibration based on target rotation speed estimation value.The application has low computational complexity, strong robustness, high reconstruction accuracy and fast convergence, and can efficiently obtain super-resolution ISAR image with good focusing effect and accurate target size estimation value.

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.

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 application provides a RAA residual error compensation method suitable for a curve trajectory SAR, comprising: using a radius angle interpolation algorithm to perform imaging processing on obtained SAR echo data, using a new residual error modeling method to perform error modeling, and designing a residual error compensation method to perform phase error compensation to obtain a final SAR image. The radius angle interpolation algorithm is introduced into airborne curve trajectory large forward-looking SAR imaging, and under the condition of large forward-looking, there is a large approximation in the derivation process of the algorithm, there is a large residual phase error for scene edge point targets, and the imaging quality of image edge points is poor. The application compensates the residual phase error of the initial imaging result by constructing a residual phase error space model, improves the focusing depth of the algorithm under the condition of the curve trajectory large forward-looking, expands the effective imaging scene, and greatly improves the limitation of the residual error on the large forward-looking and large scene imaging.

The invention belongs to the field of antenna environment effect parameter testing, and particularly relates to an amplitude-phase calibration method for antenna environment effect parameter testing. The method comprises the following steps: measuring two groups of multi-dimensional vector data of a standard calibration antenna with or without a heat preservation wave-transparent cover to obtain basic calibration data; a wave-transparent cover insertion loss compensation factor S cover and an environmental influence compensation factor S environment are obtained through vector operation of basic calibration data, and then the two compensation factors are utilized to calibrate the amplitude-phase error of actual measurement data; and further mode filtering processing is performed on the data after amplitude-phase error compensation, so that the influence of the reflection error of the wave-transparent cover is further eliminated, and the test precision is improved.

The airborne SAR real-time self-focusing imaging method comprises the following steps: estimating Doppler center frequency based on an amplitude equalization method; iterative calculation: utilizing the estimated Doppler center frequency, introducing a migration parameter correction term delta D (eta) and a frequency modulation correction term delta Km (eta), and recalculating a distance Doppler domain signal of the current iteration round; based on the improved CSA processing chain, performing phase error compensation on each range gate by using a space-variant phase error compensation function to obtain a compensated range Doppler domain signal; carrying out distance direction and azimuth direction compression in parallel to generate a focusing image, and evaluating image quality indexes; if not, extracting strong scattering points, estimating the residual two-dimensional phase error of each range gate, fitting and updating delta D (eta) and delta Km (eta), and carrying out the next round of iterative calculation; and if so, ending iteration, and outputting the focused image of the current round. According to the method, the pixel-by-pixel suppression of motion error correction and space-variant error independent of external sensing and embedded real-time imaging processing are realized.

The invention discloses a switch self-phase-shifting passive phase shifter, which comprises a switch self-phase-shifting unit, a transmission line segment network and a phase error compensation network, and is characterized in that the switch self-phase-shifting unit comprises a single-pole double-throw switch, and the single-pole double-throw switch comprises a common end, a first throw end and a second throw end; the transmission line segment network is electrically connected with the single-pole double-throw switch and is used for providing different path lengths or equivalent phase responses for signals when the single-pole double-throw switch is in different switching states, so that a predetermined phase difference is generated; the phase error compensation network comprises an inductance element which is connected in parallel between a preset node of the single-pole double-throw switch and a reference potential; the inductance element and an inherent parasitic capacitor of the single-pole double-throw switch jointly form an LC network presenting a negative group delay characteristic in a target working frequency band, and the LC network is used for compensating a frequency-related error of a predetermined phase difference; according to the invention, the layout compactness and the array expandability are improved at the same time.

The application provides a synthetic aperture radar range-aperture space-variant motion compensation method based on linear scaling, which adopts the first step of consistent compensation in two-step motion compensation to compensate for main distance non-space-variant motion error components of panoramic echo, obtains distance pulse pressure target migration curve image data, calculates sub-aperture bandwidth parameters by using image minimum defocus principle, and first-order Taylor expansion of residual range-aperture space-variant error, further introduces linear scaling in two-dimensional time domain to compensate for constant components and linear components, synchronously completes residual azimuth phase error compensation, finally splices sub-aperture data time domain to form ideal echo data without motion error, and outputs final panoramic image through traditional imaging processing. The application realizes high-precision residual range-aperture space-variant motion error compensation, has simple principle, is suitable for airborne and missile-borne platforms with complex trajectories, has high accuracy and strong robustness, and has high practicability.

The invention discloses an amplitude-phase error self-correction and direction-finding method and system for a nested array under impact noise, relates to the field of array signal processing, and aims to solve the problem that an algorithm falls into a local optimal solution due to the fact that an existing method depends on an additional correction source. Comprising the following steps: step 1, establishing a nested array receiving data model with amplitude phase errors; step 2, constructing a cosine transform Sigmoid kernel low-order matrix of the signal; 3, carrying out initial amplitude-phase error compensation, and improving the direction finding accuracy through a diagonal loading method; step 4, amplitude-phase error self-correction is carried out; 5, performing virtual extension on the low-order covariance matrix, and estimating the direction of arrival; step 6, establishing a fitness function, and updating the amplitude-phase error estimation matrix until the amplitude-phase error estimation value converges; 7, performing phase error estimation based on a quantum lizard algorithm; and step 8, repeatedly executing the step 3 to the step 7 until the maximum cycle index is reached, and outputting a direction-of-arrival estimation angle and an amplitude-phase error estimation result.

The invention discloses a moving object imaging method, device and system. The method comprises the following steps: receiving an echo signal from a moving object, and determining a mathematical representation of the echo signal after zero-frequency filtering; in the mathematical representation, a motion phase error is determined, and the motion phase error is used for representing an additional phase introduced by the motion of the moving object in the echo signal; according to the motion phase error, a phase error compensation item is determined, and the phase error compensation item is used for counteracting phase distortion caused by the motion phase error to the echo signal; and performing compensation processing on the echo signal based on the phase error compensation item to obtain a compensation processing result, and generating an imaging result of the moving object according to the compensation processing result. According to the invention, the technical problem of poor imaging result quality caused by the increase of the motion phase error in the echo signal due to the non-linear motion of the moving object is solved.

The application discloses a nonlinear phase error compensation method of an optical fiber demodulator, and relates to the technical field of phase error compensation.The method comprises the following steps: synchronously collecting interference signals output by a photoelectric detector by an analog-to-digital converter, performing low-pass filtering and amplitude extraction on the digitized interference sequence by using a carrier wave and a twice-frequency orthogonal reference signal, calculating a current amplitude ratio according to a fundamental wave amplitude and a second harmonic amplitude, estimating a current actual phase modulation depth by using a Bessel function relationship, and generating an error signal by a digital PID.The application adjusts a driving voltage amplitude in real time by using an analog voltage control programmable high-voltage driving source, thereby guaranteeing the safety monitoring of a high-pressure gas pipeline and solving the problem of system failure caused by phase modulation depth drift in long-distance oil and gas pipeline network distributed optical fiber sensing in the prior art.

The invention relates to a method for improving high-temperature north-seeking precision of a metal resonant gyroscope. The method comprises the following steps: S1, acquiring experimental data; s2, controlling the gyroscope to work in a phase calibration state through the upper computer to obtain phase errors of the gyroscope at different temperature points; s3, processing experimental data through upper computer software matlab, performing compensation on a software part in a metal resonator gyroscope control circuit, and performing conventional output-stage temperature compensation after phase error compensation is completed; s4, after phase error and output stage temperature compensation is completed, the metal resonant gyroscope is placed in an incubator rotary table in the same posture, four-position north-seeking experiments are carried out at different temperatures, and north-seeking results output by the gyroscope are collected. According to the method, the phase error of the gyroscope is calibrated at different temperature points, a compensation model of the phase error and the temperature of the gyroscope is established, the amplitude of the gyroscope output along with the temperature change is reduced, the gyroscope precision after conventional compensation is improved, and the high-temperature north-seeking precision of the gyroscope is further improved.

The invention relates to a public phase error compensation method based on projection thermodynamic diagram assistance (PHM) in a coherent optical orthogonal frequency division multiplexing (CO-OFDM) system. According to the method, rotation and divergence three-dimensional projection thermodynamic diagram distribution characteristics, caused by phase noise, of signal points in a constellation diagram of a receiving end are analyzed, a convergence area is set with an original constellation point as the center for target optimization, and the optimal compensation phase is determined by counting the maximum number of the signal points in the convergence area. In combination with a staged test phase estimation strategy in a two-stage blind phase search (BPS) algorithm, the calculation complexity is reduced, and the compensation precision is improved at the same time. Simulation experiments show that compared with a traditional method, the method can effectively suppress common phase noise of various constellation diagrams in different shapes under 16-QAM modulation, the bit error rate performance is better under the same signal-to-noise ratio, and the spectrum utilization rate is remarkably improved.

The application discloses an IQ imbalance mirror suppression method of a zero intermediate frequency receiving array, and comprises the following steps: calculating a radio frequency signal received by each array element; obtaining M radio frequency signals after phase shifting; obtaining M intermediate frequency signals output by mixing and filtering; obtaining M baseband analog in-phase signals and M baseband analog quadrature signals; the M baseband analog in-phase signals and the M baseband analog quadrature signals are respectively subjected to A / D sampling to obtain M baseband digital complex signals; before beam synthesis of a digital array, amplitude and phase consistency of M receiving channels is calibrated to obtain M receiving channel amplitude and phase error compensation values; the M baseband digital complex signals of the digital array are subjected to channel error compensation and beam weighting compensation, and summation is performed to obtain a final beam forming output complex signal; the application has the advantages that the IQ imbalance mirror suppression capability of a multi-channel zero intermediate frequency receiving digital array is improved.

The application discloses a space target large-angle high-resolution radar imaging space-varying phase compensation method and system, a storage medium and an electronic device, and comprises the following steps: acquiring an ISAR original echo, completing a translation compensation and a distance beyond a cell correction; and converting residual two-dimensional space-varying phase error compensation into a high-dimensional parameter estimation problem based on image entropy minimization. A mean value, a step length and a covariance matrix of a CMA-ES algorithm are initialized, a candidate solution population is iteratively generated, and image entropy is calculated after compensation is performed on each group of space-varying phase coefficients to serve as fitness. An optimal individual is screened, a cumulative evolution path and a conjugate path are fused, and population parameters are adaptively updated. After a convergence condition is met, optimal coefficients are output, and a high-focusing ISAR image is reconstructed. The application overcomes the defects of a traditional gradient algorithm, such as being prone to local optimization and relying on initial values, utilizes global step length dynamic adjustment and a covariance adaptive mechanism of CMA-ES, has strong global optimization capability and noise robustness, and can still converge stably in a low signal-to-noise ratio environment.

This invention relates to a low signal-to-clutter ratio ISAR imaging method for ship targets based on multi-aperture rotation alignment. Specifically, it relates to ISAR signal processing and imaging, and more specifically to a ship target ISAR imaging method. The purpose of this invention is to address the problem that existing methods cannot simultaneously solve non-stationary Doppler blurring, sub-aperture rotation errors, and strong clutter interference during the imaging process, leading to low accuracy in ship target ISAR imaging. This invention establishes an echo signal model of the three-dimensional motion of ship targets in a marine environment and introduces sea clutter interference. It utilizes Keystone transform combined with a minimum entropy phase autofocus algorithm to compensate for range migration and phase error in the pulse-compressed signal. The full-aperture observation data is divided into multiple sub-aperture data blocks to generate sub-image sequences. A screening threshold is introduced to select high-quality sub-frames. The rotation error of each preferred sub-image relative to the reference frame is estimated and resampled for correction. Finally, a geometric mean fusion algorithm is used to preserve the strong scattering point features of the target.

The application discloses a kind of video synthetic aperture radar interframe image motion error compensation method and device, the method includes: obtaining the expression of two sub-aperture images corresponding to the original echo data of video synthetic aperture radar (SAR) acquisition;Analyze the correlation between the expression of two sub-aperture images;With correlation as objective function, analyze the gradient expression of objective function;Based on a plurality of initial points and the gradient expression, the global optimal value of quadratic term coefficient is obtained by optimizing and estimating objective function;The global optimal value of quadratic term coefficient is substituted into the approximate expression of azimuth direction motion error compensation, the approximate expression of azimuth direction motion error compensation is intercepted according to different frame pulse starting position and end position, and the approximate expression of azimuth direction motion compensation corresponding to each frame is obtained, to carry out phase error compensation to the corresponding frame of two sub-aperture images.The application can realize phase error compensation to full-aperture video SAR interframe image.

A kind of nonparametric framework-based terahertz rotating target imaging method and device, including detecting rotating target according to the difference of rotating target and stationary target echo time-frequency characteristics;Visual saliency feature map is obtained by using spectrum residual visual saliency detection, and background image and rotating target image in visual saliency feature map are separated;Two rotating target azimuth signals in rotating target image are taken as signal of interest, two signals of interest are phase-unravelled and additional Doppler center is estimated, then compensation function is constructed to compensate phase error of rotating target image, and after refocusing, the rotating target image is obtained, and finally complete high-resolution image is output.The present application avoids time-consuming parameter estimation of traditional parameterized method, and can adaptively consider background clutter, providing technical support for high-resolution rotating target imaging.