Surveying procedures

With trigonometric point determination the survey points are determined from the ground and calculated in accordance with the rules of trigonometry. These triangulation points – familiar metal pyramids at lookout points that serve as witnesses to the earliest national survey – are the result of this method.

Modern national surveying is based on signals from global navigation satellites.

Levelling is the classical and still valid method of determining heights.

With photogrammetry, survey images and photographs are used for determining the spatial location or three-dimensional form of an object.

Laser scanning refers to the linear or grid-based scanning of surfaces or objects with a laser beam in order to measure them, process them or produce an image.

The Earth’s gravity field influences practically all geodetic measurements and thus always has to be taken into account. It is determined with the aid of gravimetric measurements.

Every six years, swisstopo re-measures the national survey control network. Thanks to these measurements it is possible to obtain more precise information regarding Switzerland’s tectonic stability. Almost all geodata (i.e. data with a spatial context) that are used in Switzerland are based on one of the national survey control (fixed point) networks. It is therefore all the more important to periodically re-measure these networks. State-of-the-art satellite measurement technology is used for this purpose.