地面起伏对雷达景象匹配定位性能影响的分析

Analysis of the hypsography influence on the positioning performance of radar scene matching

雷达是通过接收一定时间间隔内电磁回波成像,它与可见光成像不同。地面高程起伏不仅导致地面景物在不同成像条件下几何分布的畸变,而且引起成像灰度特性分布上的不一致,影响雷达景象匹配定位性能。在分析地面高程起伏和雷达成像模型之间关系的基础上,提出了一种基于垂直投影的雷达实时图像校正方法。试验表明了该方法的有效性。

Radar imaging geometry, which performs imaging in the direction of slanting range at the sample time of electromagnetic echo reflection, is quite different from optical imagery. The hypsography results in not only the layover distortion of groundtruth under different imaging conditions, but also the inconsistency of intensity distribution of imaging gray. Consequently the positioning performance of radar scene matching is directly reduced. A real time adjustement method based on vertical projection, by means of analyzing the relationship between the ground elevation and the model of radar imaging, is proposed to adjust the geometric distortion of sidelooking real aperture radar image. Experimental results show that the method is effective. 