CoAuthors

Douglas Chinn (SGT Inc, U.S.A); Nikita Zelensky (SGT Inc., U.S.A.); Karine Le Bail (NVI Inc., U.S.A.)

As part of its DORIS contribution to ITRF2014 the GSC analysis center processed data from January 1993 to December 2014, contributing 1141 SINEX files in the form of normal equations for inclusion in the DORIS combination for ITRF2014. The work for ITRF2014 included numerous improvements in the measurement and force modeling as compared to the submission for ITRF2008, well as the inclusion of new satellite data such as data to Jason-2, Cryosat-2 and HY-2A. We evaluate further updates to the processing including the application of ITRF2014 as an a priori; As a test of force model improvements, we quantify the improvements in the determination of the geophysical parameters from the use of the solar array quaternions on Jason-2. On all the DORIS satellites we have noticed the dramatic increase in the RMS of fit vs. elevation below 20 degrees of elevation, probably due to multipath. We experiment with the use of downweighting function for this lower elevation data and evaluate the impact on the solutions for the geophysical parameters. One of the puzzles in the processing for ITRF2014, was the observation that the scale of the HY-2A solution was biased by ~16mm with respect to other satellites (Jason-2 and Cryosat-2) when the scale of the single satellite station coordinate solutions was compared to a reference (DPOD2008). We investigate different strategies to mitigate this anomalous behavior.