There are three methods of field surveying and mapping. Why?

Routing method, allocation method and resource method.

Field survey is mainly based on the existing survey control network (survey traverse, etc. ), using the method of "hierarchical network layout and step-by-step control", following the principle of "from whole to part, control first and then divide", using theodolite, total station and other measuring instruments to carry out field measurement and obtain the coordinate information of space objects. ?

Field measurement is a traditional measurement method. The data obtained by this method is specific and accurate, but it takes a lot of manpower and a long working period. Generally, the measured data are mapped and then input into the database of land information system. When modifying the local data of the database, you can directly input the measurement data without drawing first.

Extended data

Surveying studies the theoretical and technical disciplines of measuring and calculating the geometric position of ground points, the shape of the earth and the gravity field of the earth, measuring the natural shape of the earth's surface and the geometric distribution of artificial facilities, and combining with the geographical distribution of some social and natural information, compiling various scale maps and thematic maps of the world and local areas. Also known as measurement. It includes two main contents: measurement and drawing. Surveying and mapping is widely used in economic construction and national defense construction.

In urban and rural construction planning, land resources utilization, environmental protection and other work, it is necessary to conduct land survey and map various maps for planning management. In geological exploration, mineral development and water conservancy and traffic construction, geological survey, control survey of various building design and construction, mine survey, route survey and topographic map must be carried out. Marching operations need military maps, as well as accurate geocentric coordinates and gravity field data to ensure that long-range weapons can accurately hit targets.