The Electronic Total Station – A Versatile, Revolutionary New Geological Mapping Tool

Abstract

The “electronic total station,” which is now used routinely by engineering surveyors, provides geologists with a remarkable new tool that can accurately measure (±5 mm over 1 km) in a few seconds the position of points relative to the instrument, either as angles and distances or as x, y, and z coordinates in a given reference frame (for example, easterly, northerly, and vertically) and can download its measurements to a portable computer. The speed and accuracy of data collection makes possible not only the construction of geologic maps directly in the field but also the measurement of the attitude of structural features such as layering and lineations, thus dispensing with a relatively inaccurate compass. In addition to providing a more accurate and rapid way of doing routine mapping such as that done previously with an alidade and plane table, the instrument offers the possibility of doing completely new types of mapping, such as measuring the flow directions and velocities in a river by tracking a floating, reflecting prism. The instrument also is easily operated and requires far less training to master than does a transit or alidade. Based on our brief experience with the electronic total station, we have come to believe that it will revolutionize detailed geologic mapping.