Absolute-calibration of geodetic receivers for time-transfer: Electrical-delay measurements, uncertainties and sensitivities

摘要

Our absolute calibration bench has allowed the determination of electrical delay of each receiver at room temperature of 20 deg C with a maximum deviation about 0.1 deg C: (1) BIPM Z12-T Rx : 293.19 ns -TtP, [20 - 70 ns] (2) CNES Z12-T Rx : 292.71 ns -TtP, [20 - 70 ns] (3) CNES PolaRx2 Rx 1 : 192.30 ns (4) CNES PolaRx2 Rx 2 : 192.71 ns STDEV of 0.40 ns and 0.42 ns have been respectively performed for the electrical-delay determination of Ashtech Z12-T receivers and Septentrio PolaRx2 receivers. However some precautions must be taken into account. First one, a systematic measurement of simulator delay has to be performed at each pseudoranges acquisition. Next, a very good repeatability has been obtained on the measurement of both electrical delays of RF and 1PPS links. But TIC presents a significant uncertainty. This point will be taken into account through a timing calibration of TIC.