Professional subdivision of surveying and mapping specialty

Theories and methods to study and determine the shape and size of the earth, the gravity field of the earth and the geometric position of ground points. Geodesy is a branch of surveying and mapping.

The theoretical basis of a branch of geodesy, the basic task is to establish ground control network and gravity network, accurately determine the three-dimensional position of control points, provide control basis for topographic maps, provide basis for various engineering construction, and provide information for studying the shape, size, gravity field and its changes of the earth, crustal deformation and earthquake prediction. In this paper, seawater and seabed are taken as the objects, and the state of the ocean is studied, and the marine geoid and average sea surface, seabed and sea surface topography, and ocean gravity are determined.

And the geographical distribution of natural and social information such as marine magnetism and marine environment, and the theory and technology of compiling various charts. It provides guarantee for ship navigation safety and marine engineering construction. Photogrammetry refers to an information science that obtains, processes, extracts and expresses the information achievements of image research. The definition of traditional photogrammetry is to obtain the shape, size, position, characteristics and their relationship of objects by processing the photos obtained by optical cameras.