一种能适应月相变化的月球图像中心提取算法

A Moon Image Center Extraction Algorithm Adapted to Moon Phase Change

月球是夜间最亮的天体,测月导航可在云雾天气下有效弥补传统天文导航在夜间只能观测恒星的不足,扩大天文导航的可用范围。为实现测月导航,提出了一种能适应不同月相变化的月球敏感器图像月球中心提取算法。利用Sobel-Zernike矩算子对图像进行边缘检测,利用基于圆形性检测的搜索算法筛选月球边缘点并以此提取月球中心。经半物理仿真实验解算,该算法能够针对不同月相图像有效提取月球中心,中心提取的内符合平均精度为0.16像素,外符合平均精度为2.86″。由于在月球上观测地球也有"地相"变化,该算法同样适用于月球车地球敏感器图像中心提取。

Moon is the brightest celestial body at night. Navigation depending on the moon measurement can effectively compensate for the traditional astronomical navigation mode in which only stars are observed. It can expand the available range of astronomical navigation,especially in the cloudy weather condition at night. To realize moonobserving navigation,a lunar sensor image center extraction algorithm adapted to moon phase change is proposed in this paper. The Sobel-Zernike moment operator is used to detect the edge of the image,and the searching algorithm based on circularity detection is used to find the moon edge points for extracting the moon center. A semi-physical simulation experiment is conducted,in which moon centers of different moon phase images are effectively extracted and the internal average accuracy is 0.16 pixels,the external average accuracy is 2.86″. Since the earth also has a ＂ phase＂ change when observed on the moon,this algorithm is also applicable to center extraction for earth sensor image of the lunar rover.