Consistent modeling of the geodetic precession in Earth rotation

TL;DR

This paper presents a relativistic model for Earth's rotation that accurately accounts for geodetic precession, revealing significant errors in standard treatments that could affect high-precision Earth rotation observations.

Contribution

It introduces a consistent post-Newtonian relativistic model for Earth's rotation, correcting inaccuracies in the standard approach to geodetic precession.

Findings

Standard treatment of geodetic precession is inconsistent.

Errors up to 200 microarcseconds over a century.

Relativistic model improves accuracy of Earth rotation theories.

Abstract

A highly precise model for the motion of a rigid Earth is indispensable to reveal the effects of non-rigidity in the rotation of the Earth from observations. To meet the accuracy goal of modern theories of Earth rotation of 1 microarcsecond (muas) it is clear, that for such a model also relativistic effects have to be taken into account. The largest of these effects is the so called geodetic precession. In this paper we will describe this effect and the standard procedure to deal with it in modeling Earth rotation up to now. With our relativistic model of Earth rotation Klioner et al. (2001) we are able to give a consistent post-Newtonian treatment of the rotational motion of a rigid Earth in the framework of General Relativity. Using this model we show that the currently applied standard treatment of geodetic precession is not correct. The inconsistency of the standard treatment leads to errors in all modern theories of Earth rotation with a magnitude of up to 200 muas for a time span of one century.