利用SPECAN算法的聚束SAR成像处理

讨论了距离向去调频聚束模式SAR信号的回波模型及特点，通过对聚束SAR信号的时、频域关系的分析，给出了适合去调频后的聚束SAR数据的成像算法。该算法结合了SPECAN算法高效和标离-多普勒算法实现方位精确聚焦，与传统的距离-多普勒算法相比，成倍地降低处理的数据量，从而可实现聚束SAR的实时成像处理。对Ku波段实际飞行数据采用该算法压缩得到高分辨率的图像，验证了理论分析的正确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.