Study on a bottom topography of a lake using positioning data and depth data

The bottom topography of a lake is investigated. Numerical techniques to utilize positioning data and depth data are described. Data sets obtained in RTK-GPS positioning consist mainly of temporal, latitudinal, longitudinal, and altitudinal records. Data sets obtained in echo-sounder measurement consist of temporal records and depths. The latitudinal and longitudinal data are transformed to rectangular coordinates by the Gauss-Krüger Projection, and the resultant positional data sets are synchronized with depths to yield trajectories over the lake's floor. A bottom topography over a triangular mesh is updated using the positioning data and the depth data.