Forward Squint-looking SAR Time-Domain Imaging Algorithm Design And System Development

The missile-borne synthetic aperture radar plays an irreplaceable role in modern warfare by virtue of its advantages of working in any weather,any time,high-precision,and wide swath.The rapidly changing battlefield environment requires that the missile-borne synthetic aperture radar can obtain high-resolution images in time even under special circumstances such as forward squint-looking imaging.Based on the imaging result,interested target is recognized,and its effective information is acquired for final attack.In high-squint imaging,radar echo signal will have serious range-azimuth coupling phenomenon which leads to limitation of fast frequency domain imaging algorithm.Therefore,this thesis mainly focuses on the research of forward squint-looking SAR time domain imaging algorithm and system development.The specific content is summarized as follows.(1)The first part studies forward squint-looking SAR time domain imaging algorithm.Based on the existing Accelerated Fast Factorized Back-Projection(AFBP)algorithm,which is through spectrum fusion imaging,a spectrum-range-dependece-corrected AFBP is proposed.In spectrum-range-dependece-corrected AFBP,the slant spectrum of sub-aperture is corrected,which avoids spectrum aliasing after spectrum shifting.The effectiveness of this proposed spectrum-range-dependece-corrected AFBP in forward squint-looking is verified by simulation and actual data experiments.(2)The second part focuses on SAR time-domain imaging algorithm engineering implementation on multi-core high-performance homebred DSP FT-M6678.This part briefly introduces chip architecture and resources of FT-M6678.Based the characteristics of this chip,this part completes spectrum-range-dependece-corrected AFBP engineering implementation and optimization,which promotes the application of homebred DSP chips in the field of radar signal processing.The correctness and real-time capability of this engineering implementation is verified by simulation and actual data experiments.(3)The last part introduces the design and implementation of semi-physical simulation test system.This part completes the design and implementation of semi-physical simulation test system which mainly supplys simple interaction,fast data transmission and clear results contrast.The simulation test software as the upper computer of this system designed by Qt and the lower computer is FT-M6678.The communication between upper computer and lower computer is designed by fast ethernet.The correctness and stability of this semiphysical simulation test system is verified by simulation and actual data experiments.