Determination of Global Geodetic Parameters Using Satellite Laser Ranging Measurements to Sentinel-3 Satellites

Sentinel-3A/3B (S3A/B) satellites are equipped with a number of precise instrumentsdedicated to the measurement of surface topography, sea and land surface temperatures and oceanand land surface color. The high-precision orbit is guaranteed by three instruments: GlobalPositioning System (GPS) receiver, laser retroreflector dedicated to Satellite Laser Ranging (SLR)and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS) antenna. In thisarticle, we check the possibility of using SLR observations and GPS-based reduced-dynamic orbits ofactive S3A/B satellites for the determination of global geodetic parameters, such as geocenter motion,Earth rotation parameters (ERPs) and the realization of the terrestrial reference frame, based on datafrom 2016-2018. The calculation process was preceded with the estimation of SLR site range biases,different network constraining tests and a different number of orbital arcs in the analyzed solutions.The repeatability of SLR station coordinates based solely on SLR observations to S3A/B is at the levelof 8-16 mm by means of interquartile ranges even without network constraining in 7-day solutions.The combined S3A/B and LAGEOS solutions show a consistency of estimated station coordinatesbetter than 13 mm, geocenter coordinates with a RMS of 6 mm, pole coordinates with a RMS of0.19 mas and Length-of-day with a RMS of 0.07 ms/day when referred to the IERS-14-C04 series. Thealtimetry observations have to be corrected by the geocenter motion to obtain unbiased estimates ofthe mean sea level rise. The geocenter motion is typically derived from SLR measurements to passiveLAGEOS cannonball-like satellites. We found, however, that SLR observations to active Sentinelsatellites are well suited for the determination of global geodetic parameters, such as Earth rotationparameters and geocenter motion, which even further increases the potential applications of Sentinelmissions for deriving geophysical parameters