UNIT–3 : THEODOLITE TRAVERSING
Written in simple Diploma language, with definitions, steps, formulas, and points for numericals.
UNIT–3 : THEODOLITE TRAVERSING
3.0 THEODOLITE TRAVERSING
Traversing
Traversing is a method of surveying in which a series of connected straight lines are measured, and
the directions of these lines are determined using a theodolite.
Theodolite Traverse
A traverse in which lengths are measured by chain/tape and angles are measured by theodolite is
called a theodolite traverse.
3.1 METHODS OF TRAVERSING WITH THEODOLITE
1. Included Angle Method
Angles measured are the interior angles between two consecutive sides.
Commonly used for closed traverses.
Procedure:
1. Measure length of each traverse side.
2. Measure included angle at each station.
3. Calculate bearings from known bearing.
4. Compute latitudes and departures.
Advantages:
High accuracy
Suitable for closed traverse
2. Deflection Angle Method
Angle measured between the extension of previous line and next line.
Angle may be right deflection or left deflection.
Uses:
Roads, railways, pipelines
Merits:
Simple field work
, Quick observations
3. Bearing Method
Bearing of each traverse line is measured directly.
Bearings may be whole circle bearing (WCB) or quadrantal bearing (QB).
Merits:
Simple calculations
Useful when reference meridian is known
3.2 PLOTTING THE TRAVERSE BY COORDINATE METHOD
Coordinate Method
Traverse is plotted by calculating coordinates of each station with respect to a reference point.
Steps:
1. Calculate latitude and departure of each line.
2. Find consecutive coordinates.
3. Plot points on graph sheet.
4. Join points in sequence.
Advantages:
Accurate plotting
Errors easily detected
3.3 CHECKS FOR OPEN AND CLOSED TRAVERSE
Open Traverse
Does not form a closed figure.
Used for roads, canals.
Check:
No geometrical check possible.
Closed Traverse
Forms a closed polygon.
Checks:
Written in simple Diploma language, with definitions, steps, formulas, and points for numericals.
UNIT–3 : THEODOLITE TRAVERSING
3.0 THEODOLITE TRAVERSING
Traversing
Traversing is a method of surveying in which a series of connected straight lines are measured, and
the directions of these lines are determined using a theodolite.
Theodolite Traverse
A traverse in which lengths are measured by chain/tape and angles are measured by theodolite is
called a theodolite traverse.
3.1 METHODS OF TRAVERSING WITH THEODOLITE
1. Included Angle Method
Angles measured are the interior angles between two consecutive sides.
Commonly used for closed traverses.
Procedure:
1. Measure length of each traverse side.
2. Measure included angle at each station.
3. Calculate bearings from known bearing.
4. Compute latitudes and departures.
Advantages:
High accuracy
Suitable for closed traverse
2. Deflection Angle Method
Angle measured between the extension of previous line and next line.
Angle may be right deflection or left deflection.
Uses:
Roads, railways, pipelines
Merits:
Simple field work
, Quick observations
3. Bearing Method
Bearing of each traverse line is measured directly.
Bearings may be whole circle bearing (WCB) or quadrantal bearing (QB).
Merits:
Simple calculations
Useful when reference meridian is known
3.2 PLOTTING THE TRAVERSE BY COORDINATE METHOD
Coordinate Method
Traverse is plotted by calculating coordinates of each station with respect to a reference point.
Steps:
1. Calculate latitude and departure of each line.
2. Find consecutive coordinates.
3. Plot points on graph sheet.
4. Join points in sequence.
Advantages:
Accurate plotting
Errors easily detected
3.3 CHECKS FOR OPEN AND CLOSED TRAVERSE
Open Traverse
Does not form a closed figure.
Used for roads, canals.
Check:
No geometrical check possible.
Closed Traverse
Forms a closed polygon.
Checks:
