| The last decade has seen significant progress in analysis methods for networks of (continuously operating) GPS receivers. The progress, however, has been incremental, resulting in discontinuities in existing time-series of GPS data. The first goal of this project is to re-analyse existing GPS data (going back to 1992) using state of the art analysis methods, and produce homogeneous time-series of station positions, integrated water vapour, and other parameters. The second goal of the project is to have an in-depth investigation of systematic errors, and if possible, to mitigate these errors and improve the time series. Two novel approaches will be implemented and tested. The first approach is based on aggregated residuals in the observation domain to study instrumental and atmospheric effects (antenna, multipath atmosphere modelling, rain contamination). The latter can be observed by weather radar. The second approach, which deviates from the conventional daily processing of the GPS data, consists of binning the normal equations in small intervals (few minutes) in order to study tidal, loading and other sub-diurnal signals. The third goal of the project is to investigate and interpret the improved time series and systematic effects in co-operation with relevant user communities. |
