Introduction to Total Station
In surveying, total station is defined as the advanced electronic instrument utilised to measure vertical and horizontal angles along with distance.
In field survey, based instruments are now so extensive that it would be hard to imagine any present site surveying without it. The latest electronic technology in the surveying instruments has authorised the surveyors to collect and analyze the field data much more easily and to a higher level precision than general instruments.
The total station is combined and interfaced with electronic distance measurements (EDMs) and electronic data collectors. It can read and record vertical and horizontal angles along with slope distance.
These are handled using a multi-function keyboard which is attached to a microprocessor made into the instrument. The microprocessor can store observations using an internal memory.
Features of Total Station
(a) Angle Measurement
Angles are measured by an electronic theodolite of the total station. All features of electronic theodolite are similar to the total station.
A total station can record angle measurements from 1” to 20”. All the instruments include either dual axis compensator or single axis compensator.
(b) Distance Measurement
A total station measures a slope distance and the microprocessor uses vertical angles (vertical angles recorded by theodolite with line of sight) to calculate the horizontal distance.
Additionally, the height between the horizontal axis and prism center is also displayed by total station. Co-axial optics are used in total stations. Co-axial optics include electronic distance measurements (EDM) transmitter and receiver integrated with the theodolite telescope.
These three modes are normally available for measurements of distance.
- Standard mode : Standard mode has 1 mm resolution and 1 to 2 seconds measurement time.
- Precise mode : This mode is more accurate than standard mode. It has 1” resolution but 4 to 8 seconds measurement time.
- Tracking mode : The measurement of distance is repeated automatically at less than 1” interval.
(c) Control Panel
The total station is operated by its control panel. It includes a keyboard and multiple line LCD (liquid crystal display). The LCD is waterproof, can be lit up and some LCD has control to include different viewing angles.
The keyboard allows the user to choose different measurements and apply modes and allow special functions of software to be utilised. Angle and distance measurements are generally electronically recorded in digital form as data.
(d) Power Supply
Nickel-cadmium batteries are used to power supply. The usage time is from 2 hours to 10 hours.
Some total stations have auto power save mode. This mode helps to save power when the instrument is off or into some standby mode.
Benefits of Total Station
- Total station collects quick information.
- More than one survey can be performed at one set up location.
- Easy to measure horizontal distance.
- Construction site layout preparation is quick and efficient.
- CAD software design data can be uploaded to the data collector.
- Daily survey data can be quickly downloaded into CAD.
Drawbacks of Total Station
- The total station is costlier than other traditional surveying instruments.
- Working with total stations is not so easy, as more skilled surveyors are needed for total station surveys.
FAQs on Total Station
What is a total station used for?
Total station is mainly used by civil engineers and land surveyors, either to do topographic surveying or to set out features such as boundaries, houses and roads.
What are the operations of total station?
The total station is combined and interfaced with electronic distance measurements (EDMs) and electronic data collectors. It can read and record vertical and horizontal angles along with slope distance.
What are the main parts of total station?
It consist of theodolite and Electronic Distance Measuring (EDM) instrument.
What is total station types?
Scanning Total station, Autolock Total Station, Robotic Total Station, Prism Total Station and Total Mechanical Stationary are types of total station.
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