Increased Navigation Performance from GPS Block IIR

Willard Marquis

Abstract:	There are now six new GPS Block IIR Space Vehicles (SVs) in the GPS constellation. Five were made active in a relatively short span of 13 months from early 2000 through 2001. The sixth and oldest now has a track record of five years of superb performance. Fourteen more have been built and are scheduled to be launched over the next five years. What does this mean to the user? Has navigation accuracy been any better? What will it be like with the rest of the IIRs available? Have there been as many outages? What new capabilities and features does the IIR have? Examination of the constellation performance with the Block IIRs now added gives good news. There have been both increased navigation accuracy and increased availability of a healthy signal. This paper analyzes this increased performance in detail. It also examines the expected trend toward even greater accuracy and availability in the future, as more IIRs become the backbone of the constellation. Finally, the new Block IIR features are highlighted: those which are currently implemented (e.g., the advanced Rubidium Clocks) as well as those that are yet to come (e.g., Modernization with the new Civil Signal code on L2, even better clocks, and enhanced L-band signal power).
Published in:	Proceedings of the 15th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GPS 2002) September 24 - 27, 2002 Oregon Convention Center Portland, OR
Pages:	1225 - 1235
Cite this article:	Updated citation: Published in NAVIGATION: Journal of the Institute of Navigation
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