ARMY TOPOGRAPHIC ENGINEERING CENTER FORT BELVOIR VA
The United States Army Corps of Engineers has been developing a Global Positioning System GPS carrier phase based positioning system for hydrographic surveying and dredging since 1988. This system provides real-time three-dimensional positions with horizontal and vertical accuracies better than 1 decimeter over ranges up to 20 kilometers from a single reference station without static initialization. The project has passed from concept development through feasibility studies, system analysis, resolution of carrier ambiguities on-the-fly OTF, to final system integration which is nearing completion. The real-time testing of the system began in March of 1993. This testing was performed under varying operating conditions to evaluate the limits of OTF ambiguity resolution for precisely positioning moving platforms. This paper will summarize the results of those tests. Early real-time tests performed have shown 1-3 centimeters in all three dimensions. The final design of the real-time system and its integration to hydrographic survey platforms also will be discussed. Global positioning system, Real time, 20 Kilometers, Resolution of carrier ambiguities on-the-fly, and subdecimeter accuracies.