New SLR-based geocenter estimates for orbit centering and impact on altimeter sea surface analysis
Event: 2016 Ocean Surface Topography Science Team Meeting
Session: Precision Orbit Determination
Presentation type: Type Oral
Increased accuracy in representation of the geocenter motion for altimeter satellite POD will ensure orbit centering more truly reflects the Earth’s center of mass, and consequently better references the altimeter sea surface to the Earth’s center of mass (CM). We have shown that the SLR-derived Ries (2013) annual geocenter model improves orbit centering (Zelensky et al., 2014). However this geocenter model was developed without consideration of non-tidal loading, including atmospheric loading, and this precludes further orbit improvement. The true geocenter is better represented with improved modeling of the center of figure which includes non-tidal surface deformation (Wu et al., 2012). Also we have shown that atmosphere loading improves station position modeling but should not be applied together with the current geocenter model (Zelensky et al., 2014). Using 6-years (2006-2011) of LAGEOS 1-2 Satellite Laser Ranging (SLR) data we evaluate a new ITRF2014-based model of geocenter variations for application to altimeter satellite orbit determination, where we forward model the station displacement corrections due to atmospheric loading. In a consistent fashion we apply these atmospheric loading corrections (which can amount to 10-15 mm for some stations) and the new CM model to further improve Jason satellite precise orbit computations, and evaluate the impact on altimeter sea surface estimates.