ABSTRACT
Satellite laser ranging (SLR) began as a concept in 1962 when Plotkin [1] of the Goddard Space Flight Center (GSFC) in Maryland, USA first proposed the development of accurate laser ranging to retro-reflectors on orbiting spacecraft in order to improve geodetic information. At that time optical and radar tracking of satellites was being used to yield tracking station coordinates at a level of accuracy of only about 100 m. The interesting geophysical processes that deform the solid Earth, such as Earth tides and plate tectonic motions, were understood at that time to be affecting station coordinates at the level of only a few centimetres over timescales varying from sub-daily to several years. It was clear that in order to challenge the theoretical work the measurement techniques would have to reach a level of accuracy of a few centimetres and the observations would need to be carried out over many years.
