INRIM Multi GNSS All-in-View: Software and Results

• Published in: 2019 Joint Conference of the IEEE International Frequency Control Symposium and European Frequency and Time Forum (EFTF/IFC) pp. 1 - 3
• Main Authors: Thai, Tung Thanh, Signorile, Giovanna, Sesia, Ilaria
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.04.2019
• Subjects: Global navigation satellite system; Global Positioning System; Laboratories; Receivers; Satellite broadcasting; Software; Software measurement
• ISSN: 2327-1949
• DOI: 10.1109/FCS.2019.8856122

Time transfer techniques have been playing a crucial role in time metrology since they allow comparison of oscillators all around the world, contributing to the generation of the Coordinated Universal Time (UTC) at the International Bureau of Weights and Measures (BIPM). The Common View (CV) technique using GPS satellites [1] has been used since the eighties for this purpose to compare local realizations of UTC at timing laboratories (namely UTC(k)); later on GLONASS satellites were also included. Currently the most used technique is the All-in-View (AV) technique [2]. Such technique relies on measurements of all satellites in view of a GNSS receiver connected to the local UTC(k), which are included in a standard file called CGGTTS [3] [4]. Currently with many GNSS being operational, an extension to the standard called CGGTTS V2E [5] has been published to include not only GPS and GLONASS, but also Galileo, Beidou and QZSS; the latter three are still not yet officially used in the frame of UTC and TAI computation [6]. This work presents a MATLAB software developed at INRIM, capable of processing different version of CGGTTS files and to compute the time offset between remote laboratory clocks (baselines) using AV technique. Preliminary results obtained using GPS, GLONASS (GLO), Galileo (GAL) and Beidou (BDS) are reported.