Abstract: The method of combining unmanned boat with network GNSS RTK technology is used to measure the topography and calculate the earthwork of an area, which coveres both land and water. The unmanned boat is used to survey the underwater topography, while the network GNSS RTK is used to measure the landform. Afterwards, the volume of earthwork is calculated through the method of DTM, which is based on irregular triangle network with the fusing data of landform and underwater topography, the underwater relief map is also obtained through the data of underwater topography, which is measured by unmanned boat. Both the volume of earthwork and underwater relief map can provide basis for project construction. The method of combining the unmanned boat and the network GNSS RTK technology proposed in this paper can provide an important reference for measurement practice of related engineering.

Key words: unmanned boat, GNSS RTK, earthwork, underwater relief map, bathymetric chart