Modeling tropospheric effects in GNSS signals has been addressed for decades through empirical models (low-cost receivers) or parameter estimation (for high accuracy applications). Previously, we have successfully applied machine learning to predict time series of GNSS tropospheric delays at known geodetic locations; the difficulty arises when we predict the delays at new locations. At our institute we have utilized least-squares collocation to interpolate in space tropospheric parameters using simplified physical models.
In this work, we propose a combination where we exploit their complementary characteristics. We use neural networks to predict time series of tropospheric delays and collocation to produce high resolution fields of tropospheric delays and/or refractivity. For the entire territory of Switzerland, we report and accuracy of 1-2 cm.
The paper can be found: external page https://doi.org/10.1016/j.actaastro.2022.10.007.