测绘学报 ›› 2015, Vol. 44 ›› Issue (10): 1078-1084.doi: 10.11947/j.AGCS.2015.20150118

• 大地测量学与导航 • 上一篇    下一篇

超大视场太阳敏感器图像质心提取算法

詹银虎1, 郑勇1, 张超1, 马高峰2, 骆亚波3   

  1. 1. 信息工程大学导航与空天目标工程学院, 河南 郑州 450001;
    2. 信息工程大学地理空间信息学院, 河南 郑州 450001;
    3. 郑州大学水利与环境学院, 河南 郑州 450001
  • 收稿日期:2015-03-05 修回日期:2015-05-07 出版日期:2015-10-20 发布日期:2015-10-23
  • 作者简介:詹银虎(1986—),男,博士生,研究方向为天文导航.E-mail:oscardad@163.com
  • 基金资助:
    国家自然科学基金(41374042;11373001)

Image Centroid Algorithms for Sun Sensors with Super Wide Field of View

ZHAN Yinhu1, ZHENG Yong1, ZHANG Chao1, MA Gaofeng2, LUO Yabo3   

  1. 1. College of Navigation and Aerospace Engineering, Information Engineering University, Zhengzhou 450001, China;
    2. College of Geographic Spatial Information, Information Engineering University, Zhengzhou 450001, China;
    3. College of Water Conservancy & Environmental Engineering, Zhengzhou University, Zhengzhou 450001, China
  • Received:2015-03-05 Revised:2015-05-07 Online:2015-10-20 Published:2015-10-23
  • Supported by:
    The National Natural Science Foundation of China (Nos.41374042,11373001)

摘要: 太阳图像质心提取是利用太阳敏感器进行天文导航的关键技术之一,直接决定了太阳敏感器的观测精度.针对超大视场太阳敏感器非圆形太阳图像质心提取问题,首先提出像面椭圆拟合算法,较好地解决了椭圆及近似椭圆形太阳图像的质心提取问题,然后进一步提出了球面圆拟合算法.该算法根据相机的投影和畸变模型,将太阳图像的边缘点映射到物方空间,对物方空间的边缘点进行球面圆拟合,从而确定太阳质心位置.在估计球面圆拟合算法的精度时,需要将太阳质心位置映射回像面.理论上,球面圆拟合算法不再需要顾及太阳图像的形状,算法更为严谨.将椭圆拟合算法和球面圆拟合算法应用到实测的太阳图像质心提取中.结果表明,椭圆拟合算法更适合处理半视场角70°~80.3°的太阳图像,平均精度约为0.075 pixels;球面圆拟合算法更适合处理半视场角大于80.3°的太阳图像,平均精度约为0.082 pixels.

关键词: 天文导航, 太阳图像, 质心提取算法, 边缘检测, 最小二乘拟合

Abstract: Sun image centroid algorithm is one of the key technologies of celestial navigation using sun sensors, which directly determine the precision of the sensors. Due to the limitation of centroid algorithm for non-circular sun image of the sun sensor of large field of view, firstly, the ellipse fitting algorithm is proposed for solving elliptical or sub-elliptical sun images. Then the spherical circle fitting algorithm is put forward. Based on the projection model and distortion model of the camera, the spherical circle fitting algorithm is used to obtain the edge points of the sun in the object space, and then the centroid of the sun can be determined by fitting the edge points as a spherical circle. In order to estimate the precision of spherical circle fitting algorithm, the centroid of the sun should be projected back to the image space. Theoretically, the spherical circle fitting algorithm is no longer need to take into account the shape of the sun image, the algorithm is more precise. The results of practical sun images demonstrate that the ellipse fitting algorithm is more suitable for the sun image with 70°~80.3° half angle of view, and the mean precision is about 0.075 pixels; the spherical circle fitting algorithm is more suitable for the sun image with a half angle of view larger than 80.3°, and the mean precision is about 0.082 pixels.

Key words: celestial navigation, sun image, centroid algorithm, edge detection, least square fitting

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