基于下降图像三维地形重建的参数自适应生成

针对基于单应性下降图像着陆区三维地形重建算法中重建参数对重建结果的影响，提出一种参数自适应生成算法计算最优重建参数.首先，根据匹配特征点对应的空间点拟合出地形近似平面，作为系列平行虚拟切分平面的参考平面，从而确定切分平面的法向和基本深度.其次，在地形近似平面两侧，分别计算特征点对对应的空间点到地形拟合平面最大距离，用于估计重建区地形高度差异.最后，根据地形高度差异和相机距地形拟合平面距离，寻找最优切分平面个数.根据这些重建参数即可计算地形重建所需单应矩阵.对比不同重建参数下的重建结果表明该参数设定方法可以达到更优重建效果.

Adaptive parameter generation in terrain reconstruction with descent images

In homography based landing area terrain reconstruction with descent images, the reconstruction parameters greatly influence the reconstruction results. Therefore a method for adaptive parameter generation was proposed to find the best parameters automatically. Firstly, an approximate terrain plane was fitted by the spatial points which were determined by the matched feature points in the descent images. The fitted terrain plane worked as the reference plane of the series of parallel slices and determined the normal vector and basic depth. Secondly, at both sides of the fitted terrain plane, the furthest distances between the 3D points and the fitted terrain plane were calculated separately, and thus the terrain height difference could be reckoned. At last, the best account of virtual slice planes was determined with the terrain height difference and the basic depth information of the fitted terrain plane. Through these steps, the homographies which were needed to recover the terrain of landing area could be worked out by these parameters. The comparison of reconstruction results of different parameters shows that the parameters obtained by the proposed method can lead to better reconstruction results without redundant calculation burden.