The King Edward Point Geodetic Observatory

During the period from 7th until 14th February 2013 Norman Teferle (University of Luxembourg) and Seth White (Unavco Inc.) visited King Edward Point (KEP) research station, South Georgia, to establish the KEP Geodetic Observatory (KEPGO). The observatory consists of an autonomous, continuous Global Navigation Satellite System (GNSS) station with auxiliary equipment on Brown Mountain, as well as, benchmarks on Brown Mountain and at KEP research station. The primary objective of the observatory is to measure vertical land movements in order to study sea level changes using the KEP tide gauge record or satellite altimeter data. Therefore, the existing tide gauge was connected to the observatory through precise levelling and campaign GNSS observations. The levelling was carried out over the tide gauge itself, two existing United Kingdom Hydrographic Office (UKHO) and four newly established KEPGO tide gauge benchmarks (TGBMs). The GNSS observations were carried out on two benchmarks and their coordinates were computed with respect to the continuous GNSS station on Brown Mountain. Taking the UKHO height information together with the levelling and GNSS results it is suggested that the UKHO TGBM on the jetty may have settled by a few centimetres over the period from 2003 to 2013 and that the UKHO height datum requires a shift of by about -1 m in order to bring it closer to a globally consistent vertical reference system. This technical report details the installation work and analysis carried out during and after the visit.