双基地聚束SAR运动误差分析

Analysis of Bistatic Spotlight SAR Motion Errors

将三维坐标系引入运动误差分析，建立了对任意匀速直线航迹双基地聚束SAR运动误差统一、清晰的分析方法；在此三维坐标系下，推导出各种运动误差引起的相位误差的计算公式。推导基于一般的双基地聚束SAR回波模型，可适用于任意匀速直线航迹的双基地聚束SAR，并且将通常的单基地SAR的运动误差分析作为一种特例也涵盖在内。给出了位置误差、速度误差和加速度误差所造成的相位误差计算公式。从推导结果得出结论：位于不同平台的同一误差，引起的相位误差是不同的；在小场景假设下，双基地聚束SAR的运动误差是空不变的．与目标位置无关。计算机仿真验证了误差分析的正确性。

A 3-D coordinate is introduced to make a new clear method for any constant velocity linear-path bistatic spotlight SAR motion errors analysis; under this coordinate calculation formulae are deduced between motion errors and phase errors. These deductions are based on a general bistatic spotlight SAR echo wave mode and can be used to any constant velocity linear-path bistatic spotlight SAR and monostatic SAR. Calculation formulae of phase errors which are induced by constant position error, constant velocity error and uniform acceleration error are given. From those formulae, we can draw conclusions that the same error on different fiat can induce different error and motion errors are space-invariable and independent of targetg position under small scene hypothesis. Computer simulations prove those error analyses are right.