基于边界点的区域目标可见时段计算方法

The Calculation Method of Regional Target Visible Window Based on the Boundary Point

光学卫星对区域目标的可见窗口计算是卫星观测任务的重要基础技术,高精度、高效率的求解算法对卫星观测任务规划具有重要意义。提出一种基于边界点访问计算的区域目标访问计算方法。该方法根据卫星幅宽将边界点进行插值,从而将对区域目标的可见性分析转化为对边界点集合的访问分析,将单次访问中第一个点的可见时刻作为可见窗口开始时刻,最后一个点的可见时刻作为可见窗口结束时刻。数值算例表明,将计算结果与商用软件STK相比,可见窗口持续时间相对误差在1s内,该算法精度满足实际需要;对区域555 km×1110 km做48 h的访问分析计算,5次计算平均耗时1.047 s,满足实际应用中的时效性要求,因此该算法在卫星对地观测的实际应用中具有一定的价值。

The visible window calculation of optical satellites for regional targets is a basic technology for satellite observation tasks,and high-precision and high-efficiency solution algorithms are of great significance for satellite observation task planning.Therefore,a regional target access calculation method based on the boundary point access calculation is proposed.The boundary points are interpolated according to the satellite width,so that the visibility analysis of regional targets can be transformed into the access analysis of the boundary point set.The visible moment of the first point in a single visit is considered as the start moment of the visible window,and the visible moment of the last point is considered as the end moment of the visible window.The numerical example shows that:when the calculation results are compared with those of the commercial software STK,the relative error of the visible window duration is within one second,meaning that the accuracy of the algorithm can meet the actual needs;when the 48 hours’access analysis and calculation for an area of 555 km×1110 km is conducted,the average time of five calculations is 1.047 seconds,meeting the timeliness requirements in practical applications.All proves that the algorithm has certain value in the practical applications of satellite earth observation.