An optical instruments generally used for the survey of building construction which effectively utilizes an Electronic Distance meter along with theodolite in conjunction. This is basically used to measure the sloping distance of the reference object along with their vertical and horizontal angles. Total station is considered as one of the most important ​land surveying instruments ​which accounts for the highest accuracy and reliability towards surveying the land.

Need for change :

The conventional method for surveying endorses tapes and chains for linear measurements and local theodolite and compass to achieve angular measurements. To ensure levelling, a leveling staff along with a dumpy level is considered optimal. Incorporating the above, the entire process turns tedious as well as time consuming. In order to overcome the limitations as stated , modern ​land surveying instruments​have been brought into use.

Instruments and their Use :

1. Electronic Distance Meter: ​It ensures direct measurements of distances of electronic instruments that rely upon propagation, reflection and sound waves. It comprises of three major elements

Infrared Wave Instruments

Light wave Instruments

Microwave Instruments

2. Total Station : ​A combination of both EDM and an theodolite to measure angular distances, a total station is light in weight , Integrated and compact. Various functions performed by ​Total Station Survey ​are data processing, angular measurements, distance measurements, data storing in Ebook, and display of data on digital fields. The major features possessed by Total station are as below

Ensures the entire control or functionalities through the central keyboard.

All the data are viewed digitally. It consists of a digital panel which is used to display values when the target is the reflector. The values could range from height, coordinate of the points observed, distances, angles etc.

The coordinates of the points or the bearer of the reflector can be recorded and stored for future reference.
There could be objects present at remote heights . A ​total station survey helps in measuring heights of inaccessible objects.
At instances when the direction of the horizontal or vertical distance needs to be kept track of for the sole purpose of locating the target, the instrument can effectively point the angle at which the theodolite needs to be tilted along with the distance by which the reflector requires to be moved.
3. Global Positioning System:​Developed the defense department of US also known as Navigation System. 24 satellites stationed at a distance of 20200 km , it can be effectively used to track target objects. All that a user requires is a receiver to locate the corresponding position. The receiver on getting the position process the signal to know the location of the point.

4. Automatic Level: ​The leveling instrument used in land Surveying that comprises of an optical compensator which ensure maintenance of the line of sight even though the instrument tilts.

Benefits :

The presence of ​total station survey ​has been found to tremendously increase the productivity in the method employed for land surveying. With modern technology and their corresponding instruments, the accuracy with which survey is done has been impressive. Along with it, the overall efficiency and productivity has also elevated. Due to the fact that they can be easily operated from a distance, it eliminates the need to have twin surveyor, the work can be efficiently achieved by one. They have mapping software that allows data to be stored in various systems. With this ,it seems to be the best in field of Surveying.