Total Station
A total station is a survey instrument that combines an electronic theodolite with a distance meter, measuring horizontal and vertical angles plus slope distance from one setup. Its onboard computer converts those readings into coordinates and heights, which is why it remains the standard tool for boundary, layout and topographic work.
The instrument most Kerala site work still runs on - angles, distances and coordinates from a single, verifiable setup.
ALSO CALLED: electronic total station · ETS · robotic total station · EDM · survey total station · total station machine
Typical specifications
Class-level figures. Individual models vary, so treat these as the range to check a quotation against rather than a guarantee.
- What it measures
- Horizontal angle, vertical angle and slope distance
- Typical angular accuracy
- 1" to 7" depending on grade
- Typical distance accuracy
- ±(2 mm + 2 ppm) to prism, class dependent
- Typical range to prism
- 3,000 – 5,000 m in good conditions
- Typical reflectorless range
- 300 – 1,000 m on a cooperative surface
- Common output
- Coordinate file, raw observation file, DXF/DWG via office software
How a total station works
01
Set up over a known point
The instrument is centred and levelled over a control point, and its height above that point measured. Everything downstream depends on this being right.
02
Orient to a reference
A backsight to a second known point fixes the instrument's bearing, so every subsequent reading lands in the project coordinate system rather than a local one.
03
Measure angle and distance
The EDM times an infrared or laser signal to a prism - or directly to a surface in reflectorless mode - while encoders read both angles simultaneously.
04
Compute coordinates
The onboard processor resolves angle and distance into northing, easting and elevation on the spot, so errors are caught in the field rather than in the office.
05
Set out or record
The same instrument works in reverse: given a design coordinate it guides the pole to that exact spot, which is how buildings and roads get pegged out.
What it is used for
- Boundary and cadastral surveys
- Building layout and setting out
- Topographic and contour surveys
- Road centreline and cross-section work
- As-built verification against drawings
- Quarry face and bench surveys
- Deformation and settlement monitoring
- Control traverse establishment
Who uses it
- Licensed surveyors
- Civil contractors
- Builders and developers
- Local bodies and revenue departments
- Engineering colleges
- Quarry operators
How to choose a total station
Angular accuracy grade
A 2" instrument costs meaningfully more than a 5" one and is worth it for control and monitoring. For plot layout and general topography, 5" is usually sufficient.
Robotic or conventional
A robotic total station tracks the prism and lets one person do a two-person job. On a site with steady daily setting-out, it pays for itself in labour; for occasional work it does not.
Reflectorless performance
Quoted reflectorless range assumes an ideal surface. On dark, wet or oblique faces you will get far less, so treat the headline figure as a ceiling rather than a working number.
Onboard software and data flow
Check how data leaves the instrument and whether it opens cleanly in the CAD package you actually use. A cheaper instrument with an awkward export costs you every single day.
Service and calibration access
A total station needs periodic collimation and calibration checks. Buying a brand nobody nearby can service turns a two-day repair into a two-month one.
What it costs
Total station price is driven mainly by angular accuracy grade, whether it is robotic, and the onboard software. Accessories - prism, tripod, tribrach, data collector - add a substantial and often overlooked share of the total. To confirm: total station price bands by accuracy grade
Total Station vs the alternatives
Total Station vs DGPS / GNSS receiver
GNSS is far faster over open ground and needs no line of sight, but fails under canopy, indoors and beside tall buildings. A total station works anywhere it can see the target. Most surveys use both.
Read about dgps / gnss receiverTotal Station vs Theodolite
A theodolite measures angles only; distances must be taped or computed. A total station adds distance measurement and onboard computation, which is why theodolites now survive mainly in teaching labs.
Read about theodoliteWhat Axisline does with a total station
FAQ
Total Station - common questions
What is a total station used for?
A total station is used to measure and set out precise positions on site - property boundaries, building corners, road centrelines, contour points and as-built checks. It records angles and distances from a known setup and converts them to coordinates immediately, so the surveyor can verify the work before leaving the site.
How accurate is a total station?
Typical instruments read angles to between 1" and 7" and distances to around ±(2 mm + 2 ppm) against a prism. In practice, achieved accuracy depends far more on careful centring, levelling, correct instrument and target heights, and good control than on the instrument grade printed in the brochure.
What is the difference between a total station and DGPS?
A total station measures angles and distances optically from a fixed setup and needs clear line of sight. DGPS/GNSS derives coordinates from satellites and needs open sky instead. GNSS is much faster across open land; a total station is the only option under canopy, indoors, in narrow streets and inside built-up areas.
How often should a total station be calibrated?
Most manufacturers recommend a calibration check at least annually, and immediately after any knock, drop or long transport. Field checks for collimation and vertical index error can be done far more often and take only minutes - they catch most problems long before a formal calibration is due.
Can one person operate a total station?
A conventional total station needs two people - one at the instrument, one on the prism pole. A robotic total station is designed for single-operator use: it locks onto and follows the prism while the surveyor controls it from the pole, which typically halves the crew on repetitive setting-out work.
Do you supply and service total stations in Kerala?
Yes. Axisline Sales & Service supplies surveying instruments with installation and operator training, runs an in-house calibration lab, and handles service, spares and annual maintenance. Survey field crews using the same instruments cover all 14 districts of Kerala, and equipment supply reaches clients pan-India.
Need a total station - or the survey it produces?
Supply, calibration and service across Kerala and pan-India, with field crews covering all 14 districts.