Improving GPS Time Transfer Accuracy with the NIST Ionospheric Measurement System

Dick Davis, Marc A. Weiss, Ken Davies, Gerard Petit

Abstract:	The NIST Ionospheric Measurement System (NIMS)uses the GPS P-codes on Ll and L2 without decoding them to measure the ionospheric delay on Ll. Data are available every 15 s for all satellites in view. 15 min linear fits to this data are available via modem. The NIMS will also automatically correct time measurements from an NBSlGPS type receiver for the measured ionospheric delay. The accuracy is shown to be a few ns by comparison with the Faraday rotation measurements from the GOES-2 satellite and by computing a time closure around the world with GPS data corrected with ionospheric measurements. The stability of the measurements is about 1 ns at 15 s, and they integrate as white phase noise to about 16 min.
Published in:	Proceedings of the 4th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1991) September 11 - 13, 1991 Albuquerque, NM
Pages:	253 - 268
Cite this article:	Davis, Dick, Weiss, Marc A., Davies, Ken, Petit, Gerard, "Improving GPS Time Transfer Accuracy with the NIST Ionospheric Measurement System," Proceedings of the 4th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 1991), Albuquerque, NM, September 1991, pp. 253-268.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In