高纬度地区GPT2w模型的适应性分析

GPT2w模型是现有精度最高的天顶对流层模型，但是应用在高纬度地区时存在较大误差.为更好地保障卫星导航定位系统在高纬度地区的高精度应用，评定了GPT2w模型在高纬度地区的精度，获取天顶对流层湿延迟、干延迟和总延迟，探讨了GPT2w模型改正对精密单点定位的影响.试验结果表明: GPT2w模型在高纬度地区的精度为厘米级，优于其在中低纬度地区的精度；南北极地区天顶对流层呈现明显季节变化特征和区域一致性特征，夏季天顶对流层总延迟高于冬季，北极地区天顶对流层湿延迟明显高于南极地区，北极地区天顶对流层随季节的变化幅度大于南极地区.PPP试验结果表明，GPT2w模型能够有效改善定位精度，适应高纬度地区的高精度定位需求. 

Adaptability Analysis of GPT2w Model in High Latitudes

The GPT2w model is the most accurate zenith tropospheric model in current, but there exists large error at high latitudes. In order to better ensure the high-precision application of satellite navigation and positioning system in high latitudes, the accuracy of GPT2w model in high latitudes is evaluated, and GPT2w model is used to obtain zenith tropospheric wet delay, dry delay and total delay, and the impact of GPT2w model correction on precise point positioning is explored. The test results show that the accuracy of GPT2w model in high latitudes is in the centimeter level, which is better than that in the middle and low latitudes. The zenith tropospheric delay in the Antarctic and Arctic regions has obvious seasonal variation characteristics and regional consistency characteristics. The total tropospheric delay in summer is higher than that in winter. The tropospheric delay in the Arctic region is significantly higher than that in the Antarctic region, and the zenith tropospheric delay in the Arctic region varies with the seasons more than the Antarctic region. The PPP test results show that the GPT2w model can effectively improve the positioning accuracy and adapt to high-precision positioning in high latitudes.