《Evaluation of the ITRF2016 GPS vertical velocities using satellite antenna z-offsets》.pdf

GPS Solut DOI 10.1007/s10291-012-0274-8 ORIGINAL ARTICLE Evaluation of the ITRF2008 GPS vertical velocities using satellite antenna z-offsets X. Collilieux • R. Schmid Received: 21 April 2011 / Accepted: 7 June 2012 Springer-Verlag 2012 Abstract We develop a method to evaluate the terrestrial related to the accuracy of vertical velocities, our estimates reference frame (TRF) scale rate error using Global Posi- supply a conservative evaluation that can be used for error tioning System (GPS) satellite antenna phase center offset budget computation. (APCO) parameters and apply it to ITRF2008. We search for the TRF in which z-APCO parameters have the smallest Keywords Terrestrial reference frame GPS Satellite drift. In order to provide realistic error bars for the z-APCO antenna phase center Space geodetic techniques drifts, we pay attention to model periodic variations and Kalman filter auto-correlated noise processes in the z-APCO time series. We will show that the GPS scale rate with respect to a frame is, as a first approximation, proportional to the Introduction estimated mean z-APCO trend if that frame is used to constrain station positions. Thus, an ITRF2008 scale rate Vertical station velocities obtained from different space error between -0.27 and -0.06 mm/yr depending on the geodetic techniques at co-location sites are not fully con- GPS analysis center can be estimated, which demonstrates sistent due to modeling errors and/or differences in the the high quality of the newly constructed ITRF2008. We conventional frame definition (Altamimi et al. 2002). The will also demonstrate that the traditional estimates of the velocity differences are usually compensated by means of GP