A New Regional Troposphere Fitting Model and Its Application to PPP

Based on the analysis of common regional troposphere surface models such as four-parameter surface model and a curve model,we propose a new kind of regional troposphere delay model based on multi-faceted functions.We use our zero-difference troposphere estimate software to process the CORS data of one province to analyze results of various types of model.The experimental results show that multi-faceted function model fitting residual RMS of the troposphere is about ±6 mm,and the convergence in the initial stage is much smaller than four-parameter surface model,greater stability between the epoch,there is no significant ups and downs,to better describe the regional troposphere.At the same time,we use different troposphere solutions to get PPP results,the two ways are random walk and model fitting.The experimental results indicate that model fit method can reduce the number of unknown parameters,and enhance strength and stability,which will improve the accuracy of the initial epochs.The accuracies of positioning after the convergence are with considerable accuracy.This new method can help to get dm-level PPP results quickly,but it doesn′t have obvious effect for improving the speed of convergence to cm-level.