Detecting the Lagoon Level Surface with GPS/RTK-Measurem ents

【摘要】：正The approach here presented is based in the use of a water surface as a reference for studying physical aspects related to the gravity field.The purpose is to use the mean surface of the lagoon system as an approximation of an equipotential surface close to geoid.Instantaneous water levels were also observed in several places with Global Positioning System(GPS) where a single reference station provides the real-time corrections,in this case,the Real Time Kinematic(RTK) is a technique used.In addition,three tide gauges that registered the heights of the water level in the lagoons were also used.It was possible to determine an approximated equipotential surface from the mean lagoon level(MLL) with accuracy better than 0.09 m and to link it with the vertical datum.How to eliminate the instantaneous water level deviation from an equipotential surface during the campaign was the main hurdle to negotiate.