滑动聚束SAR步进扫描影响分析

Analysis of impacton sliding spotlight SAR step steering scan

滑动聚束SAR系统在实际工作中通过步进扫描的方式来实现天线照射波束在方位向的扫描,然而该扫描方式会在滑动聚束SAR的成像结果中引入成对回波。为分析该成对回波的形成物理机制,建立滑动聚束SAR步进扫描的数学模型,通过泰勒展开和傅里叶级数分析具体解释了成对回波的成因,并给出了成对回波幅度及位置与步进脉冲控制数之间的定量关系。理论分析和信号仿真结果表明,该模型能够准确有效地解释这一现象,并可为滑动聚束SAR的波束扫描系统参数设计提供理论依据。

Antenna beam steering along azimuth of sliding spotlight SAR（ synthetic aperture radar） system was accomplished by step steering scan in practical operation. However,this scanning method may cause the paired-echo in the image of sliding spotlight SAR. To analyze the reason of paired-echo,the step steering scan model of sliding spotlight SAR was established. And the relationship in quantitatively between beam stepped steering and both amplitude and position of paired-echo by Tyler series expanding and Fourier series were calculated out. The theory analysis and signal simulation indicate that the model demonstrates the phenomenon well,and the model provides the theory basis for the design of the sliding spotlight SAR beam steering scan parameters.