Some considerations and developments to the operational use of differential GPS in Marine Geodesy

Abstract

Two different types of differential global positioning systems (DGPS) are used for precise positioning and navigation. The “ordinary”; DGPS combines range corrections from a reference station with carrier smoothed pseudoranges at the moving station. This method works on a routine basis and provides accuracies of down to I m or even less. The precise differential GPS concept (PDGPS) uses carrier phase observations of both stations and requires an ambiguity resolution while the user platform is moving. This technique provides accuracies of 0.1 m or less, but it is much more difficult to realize. Within this paper both concepts are discussed and presented in examples. In particular, the limitations and chances of the PDGPS technique and the possibility of its operational use are critically investigated.

Keywords:

• differential GPS
• GEONAP software
• global positioning system
• kinematic positioning
• precise differential GPS