Common View Time Transfer Using Worldwide GPS and DMA Monitor Stations

摘要

Analysis of the on-orbit Navstar clocks and of the GPS monitor station reference clocks is performed by the Naval Research Laboratory using both broadcast and postprocessed precise ephemerides. The paise ephemerides are produced by the Defense Mapping Agency (DMA) for each of the GPS space vehicles from pseudo-range measurements collected at five GPS and at five DMA monitor stations spaced around the world. Recently, DMA established an additional site co-located with the U.S. Naval Observatory precise-time site. The time reference for the new DMA site is the DoD Master Clock. Now, for the first time, it is possible to transfer time every 15 minutes via common view from the DoD Master Clock to the 11 CPS and DMA monitor stations.