A Study on the Coast Topography using Real-Time Kinematics GPS and Echo Sounder

Abstract

This research aims at investigation of accuracy potential of RTK(Real-Time Kinematic) GPS in combination with Echo Sounder(E/S) for the coastal mapping. Apart from this purpose, the accuracy of ambiguity resolution with the OTF(On The Fly) method was tested with respect to the initialization time. The result shows that the accuracy is better than 1cm with 5-minute initialization in the distance of 10km baseline. The seaside topography was measured by the RTK GPS only, on the other hand the seafloor topography was surveyed in combination of RTK GPS and E/S. Comparing to the volume of seaside measured by RTK GPS and digital topographical map, the difference of only 2% was achieved. This indicates that the coastal mapping. As a result, it has been revealed that every possible noise in surveying could be corrected and the accuracy could be improved. The accuracy of GPS data acquired in real time was as good as that acquired by post processing. It is expected that it will be useful for the analysis of coastal geographic characteristics because DTM(Digital Terrain Model) can be also constructed for the harbor reclamation, the dredging, and the variation of soil movement in a river.1. IntroductionAlthough GPS surveying with code measurement shows excellent performance in navigation or GIS data acquisition, the accuracy level is not in millimeters (mm) but in several meters (m). Therefore, the RTK GPS surveying using carrier phase should be used in the area requiring higher accuracy such as construction, dredging, ocean surveying, seismological observation, and the taking off and landing of aircrafts.______________________________________________________