摘要 为解决位置精度衰减因子( position dilution of precision, PDOP )监测评估中经常使用的等经纬度间隔格网模型(equal-interval of longitude and latitude grid, GRID_ELL)存在全球格网点分布不合理、评估统计结果有偏差、计算和存储效率低等问题,进一步开展全球PDOP长周期实时监测服务,引入两种等面积格网模型:等弧长格网模型(equal-arch-length grid, GRID_EAL)和正二十面体球面格网模型( icosahedron-based grid, GRID_IB ),并分析其与GRID_ELL模型之间的差异。结果表明,两种等面积格网模型能够显著改善GRID_ELL模型全球格网点分布不均匀的现象以及目前全球PDOP监测评估统计结果中的偏差。重点针对不同格网间距的GRID_EAL模型适用性进行测试,结果表明,5°间隔的GRID_EAL模型能在保持全球PDOP监测评估准确性的同时,在计算效率和存储上带来36.3%和34.1%的提升与优化。
Abstract:To solve the problems of unreasonable distribution of global grid points, biased statistical results and low calculation and storage efficiency of the equal-arch-length grid (GRID_ELL), which is often used in position dilution of precision (PDOP) monitoring and evaluation, we introduce the equal-arch-length grid (GRID_EAL) and the icosahedron-based grid (GRID_IB) to further develop the global PDOP long-period real-time monitoring service. We analyze the differences between them and the GRID_ELL model. The results show that the two equal-area grid models can significantly improve the uneven distribution of global grid points in the GRID_ELL model and the bias in the current global PDOP monitoring assessment statistics. Focusing on the applicability of the GRID_EAL model with different grid spacing, the results show that the GRID_EAL model with 5° spacing can bring 36.3% and 34.1% improvement and optimization in its computational efficiency and storage while maintaining the accuracy of the global PDOP monitoring assessment.
WANG Zhitao,SONG Shuli,JIAO Guoqiang et al. An Efficient Method for GNSS PDOP Assessment by Using Equal-Area Grid Models[J]. jgg, 2022, 42(6): 606-611.