Time transfer by laser link between China and France

TL;DR

This paper discusses the development and characteristics of the T2L2 laser link experiment for precise time transfer and clock synchronization between China and France, aiming to improve astrometric accuracy.

Contribution

It presents the characteristics of the T2L2 laser link system for clock comparison between China and France, enhancing time transfer precision using space-based laser communication.

Findings

Laser link provides better control than radio waves for time transfer.

Characteristics of common view and non-common view comparisons are detailed.

Supports high-precision clock synchronization for advanced astrometry.

Abstract

To advance from milli-arcsecond to micro-arcsecond astrometry, time keeping capability and its comparison among different stations need to be improved and enhanced. The T2L2 (Time transfer by laser link) experiment under development at OCA and CNES to be launched in 2008 on Jason-2, allows the synchronization of remote clocks on Earth. It is based on the propagation of light pulses in space which is better controlled than the radio waves propagation. In this paper, characteristics are presented for both common view and non-common view T2L2 comparisons of clocks between China and France.