非对称光斑照明合成孔径激光雷达宽测绘带成像研究

Investigation on Image Formation of Wide Swath Synthetic Aperture Ladar Using Non-Symmetric Beam-Pattern Illumination

合成孔径激光雷达(SAL)能实现远距离目标的高分辨成像,但是,其测绘带宽一般很小,不利于其在对地观测中的应用。针对这一问题,给出了宽测绘带SAL实际成像范围的建议,具体研究了采用方位向短、距离向长的非对称光斑照明实现宽测绘带SAL的成像处理问题。采用波动光学衍射理论,给出了这种宽测绘带SAL的详细成像理论描述和数学仿真成像演示。结果表明,由于光学的短波长特性,非对称光斑照明的宽测绘带SAL也近似遵循基本SAL图像形成方法:傅里叶变换实现距离压缩,匹配滤波实现方位图像聚焦。

Synthetic aperture ladar（SAL） can achieve long distance objects high resolutions imaging.However, the mapping bandwidth is generally small, which probably limits its applications in land surveillance.In order to solve the problem, practical imaging range of a wide swath SAL is suggested and a wide swath SAL using non-symmetric beam-pattern illumination with short azimuth size and long range size is investigated in detail. By wave optics diffraction theory, detailed theoretical descriptions of the image formation theory on the wide swath SAL as well as the mathematical simulations are given. The results show that due to the characteristic of short optical wavelength, the conventional image formation theory used in SAL data processing is approximately applied in wide swath SAL using non-symmetric beam-pattern illumination, that is, range compression by Fourier transformation and azimuth image focusing by matched filtering.