A case study of the application of GPS to lunar laser ranging timing systems

Abstract

Abstract The Hartebeesthoek Radio Astronomy Observatory is currently building a Lunar Laser Ranging station. This geodetic technique requires a good timing system to measure a round trip of laser photons from the telescope to the Moon and back to the telescope. We test the newly acquired timing system using examples of the Global Positioning System applications. Data in Receiver Independent Exchange Format was processed using GAMIT/GLOBK software. The results were compared against those derived from the Global Positioning System receivers that were integrated with a frequency standard from a hydrogen maser and a standard internal quartz. The results indicate that (i) the rubidium clock operates optimally and the clock drifted to within error margins of sub-centimetre level during the period of 2.5 seconds, (ii) the selected site for the permanent installation of the timing antenna has minimal multipath effect and (iii) we observed no improvement in Global Positioning System products derived from receivers that were integrated with different frequency standards.