The JPL IGS Analysis Center: Results from the reanalysis of the global GPS network

As one of the Analysis Centers for the International GNSS Service (IGS), the Jet Propulsion Laboratory (JPL) is participating in the 2009 campaign to reprocess the historical time series of Global Positioning System (GPS) data. We present results from our reprocessed solutions by providing internal and external metrics on the accuracy of the orbit and clock solutions for the GPS constellation, as well as the observed variations in the terrestrial reference frame and Earth orientation parameters. We discuss various analyses that were used to define our overall reanalysis approach, emphasizing those aspects of our estimation strategy and force models for the GPS constellation that may differ from other IGS centers. In addition, we present results from some preliminary analyses that have been performed as a precursor for future reanalysis of the historical GPS data, such as the impact of recently available models for tidal variations in the Earth orientation parameters and alternative models for the phase variations of the GPS transmit antennas.