The now traditional REDM survey requires the surveyor to measure individual or unique points in order to build up a comprehensive survey of the subject matter. The logical development of this technology is for the survey instrument to scan over an area at a predetermined increment and record a close net of three-dimensional points.

This is the role of the laser scanner which can scan a selected area in a very short time and produce a cloud of three-dimensional points. This cloud can subsequently be used to produce the more conventional survey formats in terms of plans, elevations, sections and surface models.

Laser scanners are still under intensive development but already a number of models exist to give a range of options from scanners which record small areas at very high accuracy and resolution to scanners which will scan whole horizons but with lower accuracies.

The laser scanner is a new but very important tool in the surveyors' armoury.