What is the height of collimation method?

Height of Collimation is the height of the horizontal plane through the telescope. In order to see the staff on the BM the instrument must be higher. To find the Height of Collimation (Instrument Height) add the staff reading to the level of the Bench Mark.

What is collimation method in levelling?

In levelling, a method of calculating reduced levels by subtracting staff readings from the level of the line of sight (collimation line) of the instrument. This method is usually favoured where it is required to obtain the levels of many points from one set-up.

What is collimation method in surveying?

The collimation method is the height-of-instrument method of leveling whereby fore-and-aft readings are made on a leveling staff by an instrument placed intermediately so that the rise or fall between the fore station and the back station is shown by a change in the staff reading. See Also: rise and fall. ii.

Is height of collimation same as height of instrument?

The RL of line of collimation is called Height of Instrument. From this, the staff readings of all intermediate stations is subtracted to get the RL at those points.

What formula is used in arithmetic check in height of collimation method?

Arithmetic check for Collimation Method: Sum of B.S. – Sum of F.S. = last R.L. – First R.L.

Is height of instrument same as height of collimation?

The height of collimation method of booking levelling runs can also be known as the height of instrument method. Terminology used in Levelling. Both methods of booking the readings of a levelling run are the same.

What are the basic differences between the height of instrument method collimation method and the Rise & Fall method of levelling?

Difference between Height of Instrument (HI) and Rise and Fall method

S.No. Line of Collimation or HI method Rise and fall method
1 It is more rapid and saves a considerable time and labour.
2 It is well adopted for reduction of levels for construction work such as longitudinal or cross-section levelling operations.