0.1米分辨率机载SAR系统的带宽实现 和成像算法研究

研究X波段0.1米分辨率机载SAR系统的超大带宽实现和高准确度成像算法要求的相关问题.深入分析频域合成带宽方法,提出一种适用于去斜率接收信号的类频域合成带宽方法,详细讨论两种方法在实现过程中的具体操作问题,包括频域方法的滤波器设计和解决类频域方法的宽测绘带混叠现象.对Chirp Scaling算法、Chirp z-transform算法和Omega-K算法的聚焦处理进行比较,分析算法的聚焦准确度和计算效率性,给出近似算法对测绘距离和测绘带宽度限制的表达式.讨论合成带宽与成像算法的联合问题,分析两种联合情况的执行过程和特点,给出频域合成带宽直接嵌入成像算法的数据处理流程.最后,通过仿真数据验证了整个分析过程和解决方法.

Airborne SAR Imaging with 0.1m Resolution:Bandwidth Management and Image Formation

This work addresses the study of bandwidth management and image formation for airborne SAR imaging with 0.1m resolution.The frequency domain synthetic bandwidth method is analyzed,and a novel quasi method that applies to deramp receive mode is proposed.Some issues arising in practical implementation of the technique are discussed,that is,the filter design and the solution to overlap.Different algorithms with integrated motion compensation(ECS/ECZT/EOK) are compared with each other in terms of their focusing processing,and some expressions for allowable range and range scene extent are presented.Moreover,analysis of an approach combining the synthetic bandwidth technique and Omega-K algorithm is presented.It offers the possibility of achievement X-band airborne SAR imaging up to 0.1m resolution.Finally,we present results on simulated data aimed at validating the whole analysis and the proposed procedure.