... Used for: comparisons between time scales comparisons between frequency standards GNSS data essentially always post-processed, with more or less sophistication GPS and Galileo frequency bands Galileo Joint Undertaking, 2005 Reminder of current GPS usage: s ignals Signals used L1 (1575.42 MHz): C/A code P code ( P1 ) carrier phase P code ( P2 ) carrier phase L2 (1227.60 Mhz): Reminder of current ... For GPS data, C/A, P1, P2 and P3 codes are provided for. ...

metrologia The leap second: its history and possible future R. A. Nelson, D. D. McCarthy , S. Malys, J. Levine, B. Guinot, H. F. Fliegel , R. L. Beard and T. R. Bartholome w Abstract. This paper reviews the theoretica l motivatio n for the leap second in the context of the historica l evolutio n of time measurement . Th e periodic insertio n of a leap second step into th e scale of Coordinate d Universal Time (UTC) necessitates frequent changes in comple x timekeepin g systems an d is currentl y th e