What is a total station?
A total station is an electronic surveying instrument that combines a theodolite (angle-measuring instrument) with an electronic distance meter and a small computer. In a single operation it measures the horizontal angle, the vertical angle and the distance to a point. From these readings the instrument immediately calculates the coordinates and level of that point.
How it works
- The total station is set up on a tripod over a known point and levelled.
- Using known reference points, it is oriented to the project’s coordinate system.
- Distance is measured with an infrared or laser beam, either to a prism on a pole, or reflectorless directly onto a wall or other surface.
- Robotic total stations track the prism automatically, so one person can measure and set out alone with the pole and a controller.
Uses in construction
- Setting out: placing grid lines, corners, foundations, piles and anchor bolts exactly where the drawings say.
- Checking during construction: verifying that columns, walls and floors are in the right place and at the right level.
- Surveying existing conditions: boundaries, facades and terrain as a basis for design.
- As-built surveys: recording what was actually built.
- Monitoring: tracking movement or settlement of buildings, sheet pile walls or quay walls over time.
Points to watch
- Stable set-up: a tripod on loose ground or near vibrating plant causes errors.
- Calibration: have the instrument checked regularly; small angle or distance errors add up over long distances.
- Check shots: always re-measure an extra known point to confirm the set-up is correct.
- Line of sight: the instrument has to see the prism. On sites with many obstacles, combining it with GNSS (GPS) measurement can be easier.
For a small renovation you rarely need a total station; a tape, spirit level and cross-line laser will do. For new builds, extensions up to the boundary or complex shapes, a surveyor with a total station is the safe choice.
Related terms
- Theodolite
- Spirit level
- Excavation pit
- Sheet pile wall
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