Since the American Mars Exploration Rover Opportunity landed on Mars in 2004, it has travelled more than 40 km, and heading-determination technology based on its sun sensor has played an important role in safe driving of the rover. A high-precision heading-determination method will always play a significant role in the rover’s autonomous navigation system, and the precision of the measured heading strongly affects the navigation results. In order to improve the heading precision to the 1-arcminute level, this paper puts forward a novel calibration algorithm for solving the comparable distortion of large-field sun sensor by introducing an antisymmetric matrix. The sun sensor and inclinometer alignment model are then described in detail to maintain a high-precision horizon datum, and a strict sun image centroid-extraction algorithm combining subpixel edge detection with circle or ellipse fitting is presented. A prototype comprising a sun sensor, electronic inclinometer, and chip-scale atomic clock is developed for testing the algorithms, models, and methods presented in this paper. Three field tests were conducted in different months during 2017. The results show that the precision of the heading determination reaches 0.28–0.97′ (1σ) and the centroid error of the sun image and the sun elevation are major factors that affect the heading precision.

中文翻译：

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基于太阳的火星探测器高精度航向确定

自2004年“美国火星探测漫游车”号登陆火星以来，它已经行驶了40多公里，基于其太阳传感器的航向测定技术在安全行驶中发挥了重要作用。高精度的航向确定方法将始终在流动站的自主导航系统中发挥重要作用，并且测得的航向精度会严重影响导航结果。为了将航向精度提高到1 arcminute的水平，提出了一种新的标定算法，通过引入反对称矩阵来解决大视场太阳传感器的可比畸变。然后详细描述了太阳传感器和倾斜仪对准模型，以保持高精度的水平基准，提出了一种结合亚像素边缘检测与圆形或椭圆拟合的严格太阳图像质心提取算法。开发了一个包含太阳传感器，电子测斜仪和芯片级原子钟的原型，用于测试本文介绍的算法，模型和方法。2017年不同月份进行了三个野外试验。结果表明，航向确定的精度达到0.28–0.97'（1σ）和太阳图像的质心误差以及太阳高程是影响航向精度的主要因素。