Introduction

A total station is an electronic/optical instrument used in modern surveying and building construction that uses electronic transit theodolite in conjunction with electronic distance meter (EDM).It is also integrated with microprocessor, electronic data collector and storage system.The instrument is used to measure sloping distance of object to the instrument, horizontal angles and vertical angles. This Microprocessor unit enables for computation of data collected to further calculate the horizontal distance, coordinates of a point and reduced level of point.Data collected from total station can be downloaded into computer/laptops for further processing of information.
Total stations are mainly used by land surveyors and civil engineers, either to record features as in topographic surveying or to set osut features (such as roads, houses or boundaries). They are also used by archaeologists to record excavations and by police, crime scene investigators, private accident Reconstructionist and insurance companies to take measurements of scenes.

Principle

It is based on the measurement of time for the distance travelled by wave.
1) Total Station Generates a beam that is sent to the prism and returned back.
2) The Time-of-Flight is determined by the Total Station.
3) Knowing the speed of light,the distance can be computed as- Distance = Velocity x Time.

Equipments Used

1) Total station and tripod.
2) prism and tripod.

Dos and Don'ts

Dos

1. Center and level the base of plane table accurately.
   
2. Crosshairs must be focused sharply.
   
3. Measure height of the instrument and height of prism above ground.
   
4. Always take 3 or more observations of each point to take the average.
   
5. Apply check for horizontal angles.
   
   

Don'ts

1. Handle the Total Station and Prism with utmost care.If dropped accidently, Digital display of Total Station may get damaged and Prism may also be broken.
   
2. While shifting the instrument from one station to another station, always keep it in box for transport.
   
3. Protect the instrument from heavy rains.