討論了距離向去調(diào)頻聚束模式SAR信號(hào)的回波模型及特點(diǎn)，通過對(duì)聚束SAR信號(hào)的時(shí)、頻域關(guān)系的分析，給出了適合去調(diào)頻后的聚束SAR數(shù)據(jù)的成像算法。該算法結(jié)合了SPECAN算法高效和標(biāo)離-多普勒算法實(shí)現(xiàn)方位精確聚焦，與傳統(tǒng)的距離-多普勒算法相比，成倍地降低處理的數(shù)據(jù)量，從而可實(shí)現(xiàn)聚束SAR的實(shí)時(shí)成像處理。對(duì)Ku波段實(shí)際飛行數(shù)據(jù)采用該算法壓縮得到高分辨率的圖像，驗(yàn)證了理論分析的正確性和所用方法的可行性。

This article discusses the character of range-dechirped spotlight SAR signal, analyzes the time and frequency domain character of dechirp SAR signal, presents imaging method of spotlight range-dechirped raw data.The new algorithm combines the advantages of two processing approaches: the efficiency of SPECAN algorithm and the precision of stripmap focusing technique, the first step of the proposed algorithm implements deramp technique representing a simplified version of the SPECAN approach, the second processing carries out the residual focusing via the use of a conventional stripmap processing procedure,in comparison with the range doppler method,this algorithm decreases the processed data with a little amount of calculation increased.The Ku band airborne spotlight SAR imaging experiment confirms its availability.