测站气温与气压对GPS定位结果的影响

分别利用全球气压气温模型GPT和GPT2处理相同的连续观测站数据。对比两组测站位置估值（简称位置）发现，测站气压偏差所导致的先验天顶延迟偏差不能完全被延迟参数所吸收，导致测站垂向位置出现偏差，且偏差的大小与测站纬度及数据处理中所采用的数据权重有关。测站气温偏差对测站位置的影响可忽略不计，但GPS定位结果的内符合精度随着测站气温的升高而降低。

Impact of Surface Temperature and Pressure of GPS Site on Position Estimates

In high-precision GPS analysis, the surface temperature and pressure of GPS sites are used to derive a priori zenith tropospheric delay. By comparing the different estimates of site position obtainedusing the global model of pressure and temperature GPT and GPT2 respectively, we find that the deviation of a priori zenith tropospheric delay due to the site pressure deviation cannot be absorbed completely by the delay parameters. Further, it will cause the deviations of site position estimates, especially for the vertical component; these deviations also depend on site latitude and elevation-dependent data weighting used in the data analysis. The site temperature deviations will not affect the site position estimates clearly. However, statistical analysis based on a large amounts of data show that the accuracy of position estimates decreases with the increase of site temperature. Taking the results of regional network in 2013 as an example, when site temperature increases from 0 ℃ to 30 ℃, the repeatability of daily solutions occupied 4 d decreases from about 1 mm to about 2 mm, and from about 3 mm to about 6 mm for the horizontal and vertical components, respectively.