Triangulation system may be classified according to Degree of accuracy required Magnitude of work

Photographic surveying also called photograph icing is a method of surveying in which plans or maps are prepared from photographic taken at suitable camera stations or photographic is the science of making measurement from photographs. In terrestrial photo-grammetry maps are prepared from terrestrial (or ground) photographs or terrestrial

It is the branch of surveying which deals with any body of still or running water such as a lake, harbor, stream or river. Hydrographic surveys are used to define shore line and under water features. Hydro-graphic surveying are carried out for one or more of the following activities.

The survey of the shore line of a river is made by running a theodolite and tape traverse on a shore at a convenient distance form the edge of the water. If the river is narrow, a single theodolite and tape traverse is on one bank and both banks. Located by staid or plane table methods. If the river is wide, it is necessary to run traverses on both banks and locate each shore

In an extensive survey, the primary horizontal control is established primary horizontal control secondary once by running theodolite and tape traverse b/r the triangulation station, the traverse lines being run to following the shore lines approx. in survey of less extent the primer horizontal, control only is required and is established by running a theodolite and tape