条带式合成孔径激光雷达光轴影响距离成像研究

Influence of Optical Axis on Range Imaging in Stripmap Synthetic Aperture Ladar

条带式合成孔径激光雷达(SAL)系统中光轴角包括俯仰角和水平偏离角两方面,其中光轴的水平偏离角会导致发射孔径运动轴与其孔径方位向坐标轴不平行,从而导致距离向图像失真。从理论出发推导出了两轴夹角与其失真关系的公式,并通过实验观察验证了由此引起的距离向图像失真。在实际的条带式SAL系统设计中,这种严重的图像失真是必须要解决的问题。通过点目标对系统进行校正的方法,消去了因两轴夹角而产生的距离向和方位向之间的耦合,是保证SAL系统能进行复杂面目标成像的必要条件。

The angles of optical axis in the stripmap synthetic aperture ladar（SAL） system include two aspects：the pitch angle and the horizontal angle.The horizontal angle leads to the fact that the antenna aperture moving axis is not parallel to the azimuth moving direction which causes the image distortion.Formulas are deduced theoretically on the relationship between two-axis angle and distortion,and experiments are carried out to prove this situation.The results show that the image distortion is severe in the actual stripmap SAL system.The way on image correction eliminates this coupling on range and azimuth direction,and is necessary for the complex two-dimensional imaging.