EUROMET project 529: Results of the 2004 GPS receiver calibration campaign

The goal of the EUROMET Project 529 is to extend the GPS receiver calibrations performed by the BIPM to all the European Laboratories that contribute with their data to the computation of the TAI. During 2004 a TTR6-AOA GPS receiver from ROA has been sent to selected European Laboratories with some expertise in former GPS calibration trips, to elaborate a procedure valid within Europe. A relevant result of the experience is that the pilot laboratories, ROA and VSL, have gained a valuable experience allowing to increase the performance of the 'traveling standard' and have confidence in the results. In this paper the results of the year 2004 calibration trip are exposed including the expression of the considered uncertainties well below ten nanoseconds.