Analysis of possibilities of referential transformation and update of estimated coordinates using PPP

The official reference system adopted in Brazil is SIRGAS2000 (ITRF2000 densification) and was materialized at the epoch 2000,4. Since the GPS week 1709 (07/10/2012), the IGS (International GNSS Service) reference frame, including IGS ephemerides, is the IGb08 (ITRF2008). Thus, the online PPP services provide the coordinates of the GNSS stations in IGb08, at the epoch of GNSS data collection. Therefore, it becomes necessary to perform the transformation of IGb08 reference frame (ITRF2008, epoch of GNSS data collection) for SIRGAS2000 (ITRF2000, epoch 2000.4). For this purpose, there are at least 45 possibilities, because there are at least 3 sets of transformation parameters that can be combined with at least 15 velocity models. The objective of this paper is to evaluate these possibilities in the IBGE-PPP. To accomplish this task, were processed GNSS data of 86 stations of Permanent GNSS Network of Brazil (15/07/2013). The results show that the best possibility of transformation between reference frames and coordinate update, on average, is one that uses the transformation parameters supplied by Luzum and Petit (2010), combined with the velocity field model MORVEL2010.

Keywords:
IBGE-PPP; velocity field; GNSS; transformation parameters