时域合成带宽方法:一种0.1米分辨率SAR技术  

Time Domain Synthetic Bandwidth Methods:a 0.1m Resolution SAR Technique

作　　者：白霞[1] 毛士艺[1] 袁运能[1] 

机构地区：[1]北京航空航天大学203教研室,北京100083

出　　处：《电子学报》2006年第3期472-477,共6页Acta Electronica Sinica

摘　　要：随着机载SAR系统的分辨率要求提高到0.1米,超大带宽的实现成为系统设计的技术难题,基于综合ch irp波形的合成带宽(syn thetic bandw id th)技术是一种低价格的解决方法,它可以降低系统的瞬时带宽和采样率要求.本文深入分析基本接收模式和去斜率接收模式下的两种时域合成带宽方法,扩展了基本接收模式下的原有算法的应用条件,讨论了方法实现中的参数选择与执行细节等相关问题,并特别指出宽测绘带条件下的去斜率接收信号合成带宽的实现过程.为了进行算法的真实数据验证,基于对SAR回波数据的物理含义的理解,提出一种单载频SAR原始数据转换为步进载频SAR原始数据的方法.最后,对仿真数据和真实数据应用合成带宽技术进行处理,成像结果展示了方法的可行性.Current high resolution airbome SAR systems aim to produce SAR imagery at resolution less than 0.1m. This demand poses a lot of technological and methodological problems, which have to be solved. The most important problem is bandwidth management. It can be realized by means of the synthetic bandwidth technique, an advantage of which is the reduction of the instantaneous bandwidth and sampling rate requirements of the radar system. This paper demonstrates two time domain synthetic bandwidth methods, which are respectively applied to basal receive and deramp receive mode. Based on analysis of the processing steps of original methods, the modified methods are proposed, and some issues arising in practical implementation of the technique are discussed. More particularly, the parameters choice and the overlap division processing steps of the second method in wide swaths are pointed out specifically. Moreover, according to the spectral representation of the received signal, an approach of conversion from single center frequency SAR raw data to stepped center frequencies SAR raw data is brought forward, and some results of verification of these methods are shown.

关 键 词：合成带宽 高距离分辨率 机载SAR 

分 类 号：TN951[电子电信—信号与信息处理]