Traverse in Surveying

Traverse in surveying is the series of connected survey lines whose distance is measured with the help of tape & chain and direction is measured with the help of compass or theodolite, from one point to another point in the field is called traverse in surveying.

TYPES of Traverse

OPEN TRAVERSE

The traverse lines which does not return to its starting point in the survey lines is called open traverse. Generally these goes very long distances as shown in fig below the open traverse start with point A to B, C, D, E and so on…

Example of open traverse – Railway line traversing, Road line traversing, river traversing etc.

 

CLOSE TRAVERSE

The traverse lines in the survey which forms a close loop means the return on its original starting position is called close traverse. These are mainly small distance traverse as shown in fig above that the traverse start with point A to B, C, D, E and again A.

Example of close traverse – Close polygon survey on the field, for any building complex etc.

ALSO READ Chain Surveying

What are the various method of doing theodolite traversing ? Describe the deflection angle method in detail ? – SSC JE 2007

 

Theodolite traversing

The traversing in which we use the surveying instrument theodolite. The angle measurement in the traversing is done by the theodolite.

Method of Theodolite traversing

The following method are used for theodolite traversing

• Deflection angle method
• Direct angle method
• Included angle method
• Loose needle method
• magnetic bearing method

Deflection Angle Method

The theodolite traversing in which deflection angle is measured by the next point.

At every point the theodolite is setup on zero sighting towards back-sight after that rotate the theodolite by 180 degree and sight towards fore-sight and measure the deflection angle.

The error in angle measurement is checked immediately by whole circle bearing (WCB).

WCB of a traverse line = Forward WCB of the preceding line ± deflection angle.