小行星表面形貌测绘是深空小行星探测的首要任务。提出了一种适应探测器抵近观测的立体视觉在线测绘小行星形貌的方法,即先由立体相机获得所摄重叠区的三维地形,再用前后立体模型的连接点将各个独立模型连成一个完整地形信息,经整体最小二乘平差,确定小行星的形貌模型及特征;同时提出了一种基于等值线分析的撞击坑特征提取方法,即通过提取、分析地形等值线识别出地形中撞击坑特征。实验结果显示,本文所构建的原型系统能够快速重建出探测区域的三维地形,并识别出地形中撞击坑特征,证明了所提方法具有实用性。
Asteroid surface topography surveying and mapping is the first mission of deep space exploration on asteroids. Thispaper puts forward one method of stereo vision online surveying and mapping the asteroid surface topography when detectorapproaching observation. It can obtain the 3D terrain of overlapping area by stereo camera,and connect adjacent models by theirconnection points,determine the shape model and characteristic of the asteroid by means of least squares adjustment. It also putsforward one method of crater feature detection based on contourline analysis,and the crater features in the terrain are identified byextracting and analyzing terrain contour line. Experimental results show that the prototype system can quickly rebuild the 3d terrainofexploring area,identify impact craters from the 3D terrain,and it is proved that the proposed method is practical.