Application of a no-fiducial approach to SLR data reduction

Satellite Laser Ranging (SLR) data reduction is generally done in the coordinate frame defined by the SLR tracking sites. To overcome the unreasonable, inconsistent, repetitive definitions of coordinate frame, we carried out a “no-fiducial” approach to the solution of Earth Orientation Parameters (EOP) and site coordinates experimented under using the LAGEOS-1 SLR data of the year 1999. The application of the no-fiducial approach to SLR data reduction is different from that in GPS in that SLR data are too sparse to provide a rigid polyhedron of the tracking sites. Additional constraints must be imposed to avoid rank defect of the normal equations. The RMS for site coordinates is 1.3cm after having the site coordinates transformed to the ITRF97 coordinate system. Compared with the IERS eopc04 series, the EOP derived here differ by 0.37mas and 0.30mas in the Xp and Yp components, and by 0.018ms in the Length of Day (LOD).