But most of topographical map database produced by survey department is only cartographic data, which is vector data structure, but cannot be imported into GIS directly to meet GIS using.

CASS, which is the topographical and cadastral survey system, not only can link digital mapping system and interface of GIS, but also customize the personal code and custom the cartographic symbol.

By methods of engineering drilling and geophysical investigation, this survey had ascertained the topographical feature of seabed, strata structure and physical mechanics property within survey area.