Study On The FMCW Ground-based Sar Real-time Image Processing Technology

Frequency modulation continuous wave(FMCW)SAR have characteristics of simple structure,low peak power.As compared with traditional SAR system,it has the advantages of small size,light,low cost,etc.And now,FMCW SAR is more and more used in civil and military fileds.This paper studies the method of sampling down the azimuth direction data and the technology of real-time processing.The main research of the work in this paper are as follows1.The real-time imaging algorithm is analyzed according to the features of FMCW GBSAR.The model of a point target is achieved.And the BP imaging algorithm of polar coordinates is used to achieve the requirements of high accuracy and high real-time property.2.Mean filtering method of lowered down the azimuth direction data are presented to solve the problem of serious over sampling at azimuth direction.And then the ratio of signal to noise is analysed.The numerical simulations analysis was carried out to analyze effect on imaging and the selection condition of how to lower down the azimuth direction are given.And the verifyied by measurements data are arranged.3.The implementation on the real-time processing technology of FMCW GBSAR is developped.Studied the key technology of real-time processing,such as the very long points FFT,SYS/BIOS,multi-core synchronization and communication.Finally,the correctness and effectiveness of SAR parallel imaging design was verified by measured data.