Timescale Naming Conventions

GPSTGPS system time
GSTGalileo system time
trcvTime in the local receiver timescale; the receiver timescale is realized through the oscillator of the GNSS receiver and a clock model that is continuously updated in the real-time navigation filter to minimize the difference between the receiver timescale and GPST or, alternatively, GST.
tCODETime in the reference timescale of precise GNSS clock products of the Center for Orbit Determination in Europe (CODE); the CODE timescale is realized through a highly stable hydrogen maser clock and closely aligned to GPST.