基于空间统计方法的电离层折射修正技术

摘要

针对中国上空电离层所具有的特殊性和GPS观测站在中国西部分布相对稀疏的特点,尝试探索中国卫星增强系统电离层时延信息修正技术,为卫星导航定位以及遥感、遥测等空间应用工程的电波修正提供数据.利用中国地壳形变监测网提供的双频GPS数据,以空间统计方法为主要工具,给出了普通Kriging电离层估计算法,构建了平静期和磁暴期电离层理论变异模型,详细分析了电离层折射修正的精度.结果表明,将空间统计方法应用于卫星增强系统中的电离层时延改正问题,有利于提高增强系统的电离层折射修正精度,特别是在观测样点相对较少的情况下,有利于系统完整性的实现.%Considering the particularity of ionosphere over China and scattered GPS stations in the west, ionospheric refraction correction technologies was explored to provide accuracy data for the single-frequency users of the navigation positioning and remote sensing systems based on satellite. Employing variogram and ordinary Kriging as main tool, this paper elaborated the main idea of ordinary Kriging ionospheric delay correction. Exponential model that is possibly close to the ex- periment variogram was established respectively considering the quiet and stormy cases. This paper discussed in detail the precision of SBAS ionosphere correction for China region using dual GPS data from Chinese crust deformation monitoring net. Also, result from Kriging is compared with that from planar distance interpolation. The relevant results reveal that Kriging method can improve the accuracy of ionosphere correction and guarantee the integrity of system especially for scattered sample in the cover region.