一种聚束式同轨双基地SAR的FS成像算法

Deramp based frequency scaling algorithm suitable for tandem bistatic SAR in the spotlight mode

基于同轨构型下严格解析的双基频谱和谱分析方法,提出了一种适用于同轨构型下聚束式双基地SAR成像算法.首先,类比单基情形,推导出了双基地情形下的deramp函数,实现方位向的粗聚焦,有效地消除系统方位向的频谱混叠问题.然后基于同轨构型下严格解析的双基频谱,通过一种适用于聚束式双基地SAR的频率变标成像算法校正目标的距离徙动,取得理想的成像效果.频率变标算法通过相位相乘代替插值操作实现目标的距离徙动校正,可以实现快速成像.精确的双基频谱使得所提算法可以进行长基线情形下的数据处理.仿真实验验证了算法的有效性.

Using an analytical bistatie spectrum and the spectrum analysis （SPECAN） method, an algorithm that is suitable for constant-offset spotlight bistatic SAR is presented. Firstly, the deramp function for bistatie SAP, is deduced by analog of the monostatic case, which accomplishes the coarse focusing in the azimuth direction and solves the azimuth spectral folding problem effectively. Then an analytical bistatic spectrum based frequency scaling algorithm is applied to achieve the range cell migration. correction, which is implemented through phase multiplication instead of interpolation. Data obtained with the large baseline can he processed accurately. The effectiveness of the proposed algorithm is verified with simulation experiments.