Long-time coherent integration(LTCI)can remarkably improve the detection ability of radar for moving target.To increase the processing efficiency,this paper proposes a novel LTCI method based on segment time reversing...Long-time coherent integration(LTCI)can remarkably improve the detection ability of radar for moving target.To increase the processing efficiency,this paper proposes a novel LTCI method based on segment time reversing transform(STRT)and chirp z-transform(CZT).In this method,STRT operation is first presented to estimate the Doppler ambiguity factor,and keystone transform(KT)is used to correct the whole range migration(RM).Then,CZT and non-uniform fast Fourier transform(NUFFT)are used to estimate the parameters as well as correct the second and third order Doppler frequency migration(DFM).Compared with the existing methods,the proposed method can achieve RM correction and DFM correction without repetitive operation.The effectiveness of the proposed method is validated by both simulated and real data.展开更多
A space-based bistatic radar system composed of two space-based radars as the transmitter and the receiver respectively has a wider surveillance region and a better early warning capability for high-speed targets,and ...A space-based bistatic radar system composed of two space-based radars as the transmitter and the receiver respectively has a wider surveillance region and a better early warning capability for high-speed targets,and it can detect focused space targets more flexibly than the monostatic radar system or the ground-based radar system.However,the target echo signal is more difficult to process due to the high-speed motion of both space-based radars and space targets.To be specific,it will encounter the problems of Range Cell Migration(RCM)and Doppler Frequency Migration(DFM),which degrade the long-time coherent integration performance for target detection and localization inevitably.To solve this problem,a novel target detection method based on an improved Gram Schmidt(GS)-orthogonalization Orthogonal Matching Pursuit(OMP)algorithm is proposed in this paper.First,the echo model for bistatic space-based radar is constructed and the conditions for RCM and DFM are analyzed.Then,the proposed GS-orthogonalization OMP method is applied to estimate the equivalent motion parameters of space targets.Thereafter,the RCM and DFM are corrected by the compensation function correlated with the estimated motion parameters.Finally,coherent integration can be achieved by performing the Fast Fourier Transform(FFT)operation along the slow time direction on compensated echo signal.Numerical simulations and real raw data results validate that the proposed GS-orthogonalization OMP algorithm achieves better motion parameter estimation performance and higher detection probability for space targets detection.展开更多
基金the National Natural Foundation of China(Nos.61771046,61731023 and 62171029).
文摘Long-time coherent integration(LTCI)can remarkably improve the detection ability of radar for moving target.To increase the processing efficiency,this paper proposes a novel LTCI method based on segment time reversing transform(STRT)and chirp z-transform(CZT).In this method,STRT operation is first presented to estimate the Doppler ambiguity factor,and keystone transform(KT)is used to correct the whole range migration(RM).Then,CZT and non-uniform fast Fourier transform(NUFFT)are used to estimate the parameters as well as correct the second and third order Doppler frequency migration(DFM).Compared with the existing methods,the proposed method can achieve RM correction and DFM correction without repetitive operation.The effectiveness of the proposed method is validated by both simulated and real data.
文摘A space-based bistatic radar system composed of two space-based radars as the transmitter and the receiver respectively has a wider surveillance region and a better early warning capability for high-speed targets,and it can detect focused space targets more flexibly than the monostatic radar system or the ground-based radar system.However,the target echo signal is more difficult to process due to the high-speed motion of both space-based radars and space targets.To be specific,it will encounter the problems of Range Cell Migration(RCM)and Doppler Frequency Migration(DFM),which degrade the long-time coherent integration performance for target detection and localization inevitably.To solve this problem,a novel target detection method based on an improved Gram Schmidt(GS)-orthogonalization Orthogonal Matching Pursuit(OMP)algorithm is proposed in this paper.First,the echo model for bistatic space-based radar is constructed and the conditions for RCM and DFM are analyzed.Then,the proposed GS-orthogonalization OMP method is applied to estimate the equivalent motion parameters of space targets.Thereafter,the RCM and DFM are corrected by the compensation function correlated with the estimated motion parameters.Finally,coherent integration can be achieved by performing the Fast Fourier Transform(FFT)operation along the slow time direction on compensated echo signal.Numerical simulations and real raw data results validate that the proposed GS-orthogonalization OMP algorithm achieves better motion parameter estimation performance and higher detection probability for space targets detection.
