The offshore positioning market has undergone massive change over the past decade. This has been brought about by the rapid acceptance of the differential use of the Global Positioning System (GPS) as the primary means for precise navigation. Within the space of a year, the evolution of differential GPS (DGPS) had devastated the traditional market for the existing radio positioning systems. Bearing this in mind, the commercial DGPS market is now itself potentially on the brink of enormous change. Operational DGPS services that are provided free of charge by many governments have mainly been responsible for this change; these services existed primarily to enable safe navigation in coastal waters, however, they are also used for precise navigation by the offshore industry. Additionally, further GPS augmentations are currently under development by various nations to enable safe and precise navigation in the field of civil aviation. These "wide area" schemes are due to be operational in North America and Europe before the end of the decade. This paper attempts to predict the effect that these government sponsored augmentation schemes will have on the future commercial market for DGPS, particularly with regard to the transmission of DGPS correction messages via communications satellites. Potential changes to the control mechanism and hardware of the GPS satellites are also discussed, with reference to their possible effects. This paper describes the current market for DGPS with a summary of how the commercial systems evolved, followed by an introduction to the various planned augmentation schemes and a discussion of how these may affect the DGPS market. Various scenarios are also considered for the future of the DGPS market.
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