Electronic Distance Measurement

Electronic distance measurement (EDM) equipment is used in surveying, essentially capturing the distance between two theodolites. Total stations, meanwhile, can be used to measure distance and angles.

Devices known as total stations share similarities with theodolites and can be used to measure distances as well as angles. The telescope on a transit theodolite will also rotate, enabling back-sighting with data collected and made available for triangulations through a built-in computer interface.