Report

On
Linear Measurements

Name : R.M.L.W.Bandara
Reg.No : 6866
Resignation : Survey Student
Date :

Department of Spatial Sciences

Faculty of Built Environment and Spatial Sciences
General Sir John Kotelawala Defense University - Southern Campus
 Contents

1.0 Introduction ........................................................................................................................................ 3

2.0 Objectives and Usages ....................................................................................................................... 4

2.1 Objectives ....................................................................................................................................... 4

2.2 Usages ............................................................................................................................................ 4

3.0 Methodology ...................................................................................................................................... 5

3.1 Equipment Used ............................................................................................................................. 5

3.2 Field Work...................................................................................................................................... 5

3.3 Office Work .................................................................................................................................... 5

3.4 Plan Work ....................................................................................................................................... 5

4.0 Discussion .......................................................................................................................................... 6

5.0 Document Annexed............................................................................................................................ 8

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 1.0 Introduction
The process of measuring distances between points on a surface is called Linear Measurement.

Usually this is done with a tape measure, but can also be done with lasers. There are three methods of linear
measurementsin surveying.
1) Direct method –
 Approximate method (By Pacing/ Stepping, Passometer, Speedometer/Odometer)
 Chaining and taping method (By using chain or tape)
2) Optical or Indirect method –
 Observations are taken through the telescope, and calculations are done for distance as in
tachometer or triangulation.
3) Electromagnetic method
 The instruments used in the electromagnetic method are Geodimeter, Tellurometer, Decca
Navigator.
 The most accurate method is chaining method.
It is essential to study ranging in linear measurements.It is the process of establishing intermediate
points on a straight line between two end points.
There are two types of ranging methods.
They are,
 Direct Ranging – The rods are fixed on a straight line and end stations are intervisible.
 Indirect Ranging Method – Used to elevated ground where the end stations are not
intervisible.

There can be obstacles when chaining. Various obstacles such as woods, hills,
rivers, buildings, etc., are met with a chaining. Those obstacles can be classified as three types.

1) Chaining free but vision obstructed

2) Chaining obstructed but vision free
3) Both chaining and vision are obstructed

Special methods are employed in measuring distances across the obstructions

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 2.0 Objectives and Usages

2.1 Objectives
 Accurate distance determination
 To provide baselines and reference points that act as a basis for additional measurements and
constructions.
 Obtain horizontal distances in slopping terrain

2.2 Usages
 Carry the knowledge about linear measurements to Chain Surveying tasks.
 To get more accurate measurements in the field.

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 3.0 Methodology
3.1 Equipment Used
 Steel tape(50m) 1
 Linen tape(30m) 1
 Ranging rods 4
 Drawing Accessories

3.2 Field Work

The given task was to measure the Boo-Maluwa area including the Boo-Maluwa which is a
part of the KDU Southern Campus Garden State.

Fieldwork started on - 2024/03/16

Fieldwork ended on - 2024/04/04
Meridian - Arbitrary North

Practical Procedure:

1) First we reconnaissanced the field.

2) Next we put a cement picket on Station 1.
3) Then we put another cement picket on Station 2.
4) After, we measured the distance between Station 1 and Station 2 using ranging rods and the steel
tape.
5) We got offsets to the corners of Boo-Maluwa while measuring.
6) Finally, all measurements we obtained, entered to the field book.

3.3 Office Work

After the field work, completed my dairy on field book.

3.4 Plan Work

No plan works were done.

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 4.0 Discussion
Linear measurement practical is the first practical task that we entered the field as survey students. It is an
important practical which will be useful in our surveying career.
We learnt from this,
1) Understanding measurement techniques
 How to observe the ground
 How to place the stations correctly
 How to do the ranging
 How to take the offsets using the linen tape and what kind of places should be taken as
offsets.
2) Instrument handling and accuracy
 How to handle ranging rods correctly
 How to get the readings from the linen tape
3) Error identification and correction
 Sagging of the tapes.
 Error of measurements took by members.
 Careless measurements.
4) Field procedures
 Chaining: The process of measuring distances using a chain or tape, including setting out
lines and recording measurements.
 Triangulation: Dividing an area into triangles to measure and map it accurately
5) Data recording and interpretation
 How to use field book
 How to keep recordings
6) Practical application
 Applying these skills in real-world scenarios, such as land surveying, construction site
layout, and infrastructure development

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Advantages of this method;
1) Simplicity: Linear measurements are straightforward and easy to understand. They don’t require
complex calculations or advanced equipment.
2) Cost-Effective: The equipment used for linear measurements, such as tapes and chains, is relatively
inexpensive compared to more advanced surveying tools.
3) Accuracy: For short distances and flat terrains, linear measurements can be quite accurate.
4) Versatility: Linear measurements can be used in various surveying methods, including traversing,
triangulation, and trilateration.
5) No Need for Conversion: When surveying flat or regular terrain, there’s no need to convert data
into three dimensions.

Disadvantages of this method;

1) Limited Range: Linear measurements are less effective for long distances or in rough terrains where
it is difficult to lay out tapes or chains.
2) Environmental Constraints: Factors like wind, temperature, and obstacles can affect the accuracy of
linear measurements.
3) Labor-Intensive: The process can be time-consuming and labor-intensive, especially for large areas.
4) Obsolescence: With the advent of modern electronic and optical surveying instruments, traditional
linear measurement methods are becoming less common.
5) Human Error: Manual measurements are prone to human error, which can affect the overall
accuracy of the survey.

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 5.0 Document Annexed
 Field book/level book numbers :
 Signature :
 Name : R.M.L.W.Bandara
 Designation : Survey Student
 Date :

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