基于球冠谐分析的区域精密对流层建模

摘要

The troposphere delay is one of the major error resources for the accuracy of GPS posi-tioning.Empirical models were unable to provide sufficient accuracy for the precise positioning with increasing demand of precision,the continuously operating reference stations (CORS)built around the world shed lights on constructing more precise tropospheric delay model.Based on the analysis of drawbacks of common real-time regional tropospheric delay models,a new regional real-time troposphere model based on spherical cap harmonic analysis (SCHA)was proposed in this paper.Detailed SCHA model calculations was introduced,and the optimal the SCHA area troposphere model was established by experimental comparison analysis.In order to verify the effect of the SCHA model,the four-parameter model and rectangular harmonic analysis (RHA) model were established at the same time.The comparative analysis of modeling results from three models shows that SCHA model̓s inner coincident precision has obvious advantage (RMS<6 mm)and its externally coincident precision increases about 50% than four-parameter model (RMS<1 cm).SCHA model̓s fitting accuracy is slightly better than RHA model as a whole.SCHA model could describe special variations of troposphere more reasonably and is adequate to regional real-time troposphere delay modeling for large areas.%对流层延迟是影响GPS定位精度的主要误差来源.随着精度要求的提高,经验模型已经不能满足精密定位的需要,而许多地区建立的连续运行参考站系统为建立区域对流层模型提供了一个很好的契机.本文分析常用的对流层区域实时模型方法的不足,提出基于球冠谐(spherical cap harmonic analysis,SCHA)的区域精密对流层模型.详细介绍 SCHA模型的计算方法,并根据试验对比分析建立了最优 SCHA区域对流层模型.为了验证 SCHA模型的效果,本文将之与四参数模型和矩谐分析(rec-tangular harmonic analysis,RHA)模型进行对比与分析.其结果表明 SCHA 模型在内符合精度上有明显的优势(RMS值在6 mm 内),外符合精度相比四参数模型提高了50％左右(RMS值在1 cm 内),且建模精度整体上略优于 RHA模型.SCHA模型能更好地描述对流层的空间变化,适用于大区域对流层延迟实时建模.