基于扫描线的卫星区域覆盖分析算法

Algorithm for Satellite Regional Coverage Analysis Based on Scanline

针对传统网格点法评估卫星区域覆盖性能时运算量大且效率低的问题,提出一种改进的卫星区域覆盖分析算法。在卫星覆盖带多边形生成和目标区域包围盒网格划分的基础上,基于经度方向的网格点构造扫描线,将扫描线与目标区域的相交部分作为初始计算对象,通过初始计算对象与覆盖带多边形的求交实现扫描线的分段划分,统计扫描线分段数据得到覆盖率、覆盖重数等指标。算例分析结果表明,该算法具有较低的时空复杂度,当网格数量超过80万时,运算时间仅为传统网格点法的1.19%。

To address heavy and inefficient computations caused by traditional grid point-based regional coverage analysis of satellites,this paper proposes an improved algorithm for regional coverage analysis of satellites.After the coverage band polygon of the satellite is generated and the bounding box of the target region is divided into grids,the scanlines are constructed with grid points on the lines of longitude.The proposed method takes the intersection of scanlines and the target region as initial computational object,and calculates the intersection of the initial computational object and the coverage band polygon to segment scanlines.The data of segmented scanlines are analyzed to obtain indicators including the coverage rate and the number of repeated coverage.Analysis results of the example show that the proposed algorithm reduces the time complexity and space complexity,demanding only 1.19%of computing time of the traditional grid point method when the number of grids exceeds 800000.