Abstract's details
Impact of the next foreseen IERS mean pole model (linear) on altimeter satellite precise orbits, validation of updated measurement models (DORIS antenna phase maps and satellite geometry)
CoAuthors
Event: 2017 Ocean Surface Topography Science Team Meeting
Session: Precision Orbit Determination
Presentation type: Type Poster
Contribution: PDF file
Abstract:
To improve the orbits, it is necessary to use the best available models, for the station coordinates (e.g., SLR validation), and measurements modelling. We propose an analysis of three recent models whose effects are seen on the orbit or station coordinates of the DORIS network. This analysis is based on past and current altimeter missions from 1992 to 2017.
The accuracy of the location of the ground stations depends on the mean polar motion model (effect of the pole tide). A linear model for the mean pole was suggested at UAW 2017 (Paris) to better compute the rotational deformation due to the pole tide. Orbit solutions were computed using this model and compared to the cubic-linear model of the IERS Conventions (2010) on the contemporary missions, with the same ITRF realization coordinates. We validate the improvement looking at SLR residuals and geographically correlated orbit differences.
A new phase correction map was provided by CNES for the Alcatel DORIS ground antennas. These antennas were predominant over the TOPEX/Poseidon lifespan. The model is tested and compared to the previous one, focusing on the estimates of DORIS satellite phase center radial offset and vertical station positioning.
Finally, for Sentinel-3A, we re-estimate the phase center offsets of the three POD instruments using the measured attitude and measured orientation of the solar panels, showing that these offset corrections could be represented by an error in the knowledge of the satellite’s center of mass location.
The accuracy of the location of the ground stations depends on the mean polar motion model (effect of the pole tide). A linear model for the mean pole was suggested at UAW 2017 (Paris) to better compute the rotational deformation due to the pole tide. Orbit solutions were computed using this model and compared to the cubic-linear model of the IERS Conventions (2010) on the contemporary missions, with the same ITRF realization coordinates. We validate the improvement looking at SLR residuals and geographically correlated orbit differences.
A new phase correction map was provided by CNES for the Alcatel DORIS ground antennas. These antennas were predominant over the TOPEX/Poseidon lifespan. The model is tested and compared to the previous one, focusing on the estimates of DORIS satellite phase center radial offset and vertical station positioning.
Finally, for Sentinel-3A, we re-estimate the phase center offsets of the three POD instruments using the measured attitude and measured orientation of the solar panels, showing that these offset corrections could be represented by an error in the knowledge of the satellite’s center of mass location.