Pole Coordinates and Length of Day from Laser Ranging of Low Earth Orbiters

Abstract

This article is devoted to determining Earth’s Orientation Parameters (EOP) from reprocessing of the Laser ranging observations of the specially designed satellites. These are laser geodynamics satellites Lageos and Etalon and Low Earth Orbiters Lares, Ajisai, Starlette, and Stella. New software was created by the author and a new approach was proposed to analyze each model of geodynamics phenomena; a transformation or process was first tested separately and only then included into the package. The main attention was paid to the analysis of the possibility to use Laser Ranging data to Low Earth Orbiters for EOP determination. It was shown that, despite the much lower Lares’s orbit (height is 700 km) than the Lageos’s orbit (7000 km), the resulting EOP series from Lares data have the same precision in general. It was achieved by new software and a new author approach to the study of the models. Final EOP data sets were computed at the same time by a combination of raw EOPs from each satellite or from the combination of the conditional equations. In the latter case, the precision of the final solution is 10–15% better. It allows us to recommend Low Earth orbiters for geodynamics on a permanent basis.