GPS 大地高测量精度的季节性变化

摘要

通过对两个香港GPS参考站2004～2005年的数据进行试验和分析，发现两年高程方向坐标序列的相关系数达到0．846，这说明GPS大地高精度呈现明显的季节性重复变化。进而由气象数据分析可知：GPS大地高测量精度主要是受残余对流层延迟影响而呈季节性变化的。利用这一性质可建立残余对流层延迟误差的季节性改正模型，从而提高GPS大地高测量精度。%The GPS data of two reference GPS stations in Hong Kong GPS Reference Network from 2004 to 2005 was processed to obtain the ellipsoid heights in each day .After that , the results were compared with the original ellipsoid height of the reference stations .The correlation of the two ellipsoid height data series in 2004 and 2005 was 0 .846 .This shows that the vertical accuracy of GPS changes based on the seasons and repeats year to year .After analyzing the weath-er data in these two years ,it can be found that the seasonal change of the weather results in the seasonal change of residu -al tropospheric delay ,and then results in the seasonal change of the vertical accuracy of GPS .Based on this property ,a seasonal tropospheric delay correction model can be set up to improve the vertical accuracy of GPS .