MEANING OF TRAVERSE SURVEYING –ALL YOU NEED TO KNOW
A series of connected straight lines whose lengths and directions in the field are known as traverse. The word traverse means to pass across. In the process of traversing the direction of the survey, the line is fixed by taking the angular measurements with suitable instruments and distance by chaining of taping.
Also, A traverse is a series of connected lines whose lengths and directions are to be measured and the process of surveying to find such measurements is known as traversing. In general, chains are used to measure length and compass or theodolite are used to measure the direction of traverse lines.
Types of traverse Surveying:-
There are two types of traverse surveying.
Closed traverse: When the lines form a circuit which ends at the starting point, it is known as a closed traverse. The traverse, which returns to its starting station or to another whose location is already known as closed traverse.
Open traverse: When the lines form a circuit ends elsewhere except starting point, it is said to be an open traverse. The traverse, which does not return to its starting station or to another station is called on the open traverse. It consists of a series of connected links.
Different methods:-
The traversing is performed by four different methods and these methods are classified according to the survey instrument used. The methods are as follows.
- Chain Traversing
- Compass Traversing
- Theodolite Traversing
- Plane Table Traversing
Chain Traversing
The method in which the whole work is done with chain and tape is known as chain traversing. No angle of measurements is used, and the direction of the lines is fixed entirely by the linear measures of angles and fixed by linear or tie measurements, and it’s called chain angels.
The method is unsuitable or accurate work, and it is used if the angle of measuring instruments like complex, syntax, or theodolite is available.
In the case of compass traversing, both linear and angular measurements of traverse lines are taken by using chain and prismatic compass respectively. Both fore bearing and back bearings are measured and required corrections for local attraction are applied. If any closing error is obtained while plotting of traverse, then Bowditch rule is applied for the adjustment of error.
Theodolite Traversing
In the case of theodolite traversing, the linear measurements are done by using chain or stadia method and angular measurements are done by theodolite. Using theodolite, the magnetic bearing of the first traverse line is measured and from that magnetic bearing of other sides are calculated. This method is very accurate compared to other methods.
Plane Table Traversing
In this method, we do not use any theodolite and compass for traversing. Only we have to use a table at site and plot all the points along the traversing and also calculate the linear measurements.