Trigonometric point determination
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.

This classical method of determining points is based on measuring directions, distances and vertical angles between neighbouring points using theodolites and tachymeters (distance meters).
They form the basis for calculating the coordinates and height of the surveyed objects on the basis of the rules of trigonometry. Today, digital instruments are used for making these calculations directly.
The data are stored in the device and can subsequently be transferred to the computer system in the office for further processing. This method is also called triangulation.