16:30 〜 16:45
[G06-2-01] High-resolution troposphere models based on Numerical Weather Prediction for GNSS real-time Precise Point Positioning
Tropospheric delay is highly correlated with the receiver clock and receiver height. To efficiently de-correlate these parameters in Precise Point Positioning (PPP), a change in constellation geometry is required. An alternative approach is to introduce the external high-quality regional tropospheric delay model to constrain tropospheric estimates. In this study, we present a high-resolution troposphere model based on Numerical Weather Prediction (NWP) model and Global Navigation Satellite Systems (GNSS) data, suitable to support PPP. We investigate the impact of different tropospheric models and mapping functions on the position accuracy and convergence time. We propose a routine to constrain the tropospheric estimates, which we implemented in the in-house developed real-time PPP software. We take advantage of the spatial high-resolution NWP Weather Research and Forecasting (WRF) model to reconstruct troposphere delay from WRF model and near real-time GNSS data combined by the least-squares collocation technique. We also present mapping functions calculated from WRF model using the ray-tracing technique. We compare commonly used troposphere models such as UNB3m or VMF1-FC and the high-resolution GNSS/WRF-based troposphere model with the reference EUREF Permanent Network (EPN) data on 14 Polish stations during three weeks of different tropospheric conditions: calm, standard and severe. The application of the high-resolution model results in the best agreement with the official EPN coordinates. In both static and kinematic mode this approach results in average reduction of 3D bias by 20 and 10 mm respectively. The application of high-resolution tropospheric model also shortens the convergence time by 13% for horizontal components and 20% for vertical component compared to the standard models.