Preliminary Test of Tide-independent Bathymetric Measurement Based on Gps

A GPS system was designed to carry out so-called ‘tide-independent’ bathymetric measurement, in order to compare with the conventional technique in which the tidal observations are made at tide gauges along the coast. Through the estimation and introduction of attitude parameters and height corrections, both based on the GPS solutions, the tide-independent bathymetric measurement can be implemented without making any direct tidal observation. The data set was collected by the field test on the northwestern coast of Taiwan. The preliminary results show that the measurement quality has been effectively improved by using the proposed tide-independent technique. The bathymetric accuracy, estimated from the check points, indicated an improvement of between 7% and 26%, depending on whether the attitude correction was applied or not applied. This level of accuracy satisfies the first-order standard required for hydrographic surveys.