A GPS parallel common-view experiment

In May-June 1995 an experiment was carried out at the IREE, Prague, in collaboration with the PTB, Braunschweig, and the IEN, Turin to assess the performance of the GPS common-view time transfer to IREE. At each laboratory two GPS receivers were in parallel operation. While the first receivers were scheduled according to the recommendation of Bureau International des Poids et Mesures (BIPM), the second receivers followed a special schedule with equally-spaced tracks and with satellites at high elevations. As a comparative measure of the white-noise PM present in the common-views, the time deviation /spl sigma//sub x/(/spl tau//sub 0/) was used. The best noise performance with /spl sigma//sub x/(/spl tau//sub 0/)=1.5 ns for the sampling interval of 1 hour was shown in the case of the UTC(TP)-UTC(IEN) common-view difference measured by the second-receiver pair. A favourable impact of higher satellite elevations has been observed. Daily variations with a variable amplitude up to several nanoseconds were found in all common-view pairs. As a first step in seeking the main source of these variations, antenna temperature sensitivity of the two IREE´s receivers has been measured. All filtering throughout the analysis was realised by using Vondrak smoothing.