Cadastral survey data is based on the coordinates and heights of the Swiss national land survey (swisstopo Geodesy Division). These accurately fixed control points provide the reference framework for all survey work in Switzerland.
A fixed (control) point is a surveyed point with known coordinates and/or height which is permanently marked by means of a stone monument or a bolt (sometimes covered by a manhole).
These fixed control points form the basis for all spatially referenced data. This includes, for example, official cadastral survey data, national topographic mapping, utilities’ asset registers and mapping, geographical information system (GIS) data, building zoning plans, etc.
There are two general types of fixed points: planimetric and vertical control points. These are classified in the following hierarchy:
