2. Syllabus
Linear measurements and chain surveying: Definition of surveying, classification of
surveys, scales, types of chains and tapes, chaining and ranging, principles of chain survey,
instruments, applications, errors and corrections, obstacles in chaining.
Compass Surveying: Measurement of bearing, computation of angles from bearings,
designation of bearings, fore bearing and back bearing, prismatic compass, principles of
compass survey, local attraction and corrections, compass traverse and adjustments.
Plane Table Surveying: Instruments, working operations, different methods, advantages
and disadvantages, two and three-point problems.
Levelling: Principle, levelling instruments, dumpy level, classification of levelling, booking
and reducing levels, profile and reciprocal levelling, curvature and refraction corrections,
bubble tube and its sensitiveness, levelling difficulties.
Contd.
3. Syllabus Contd.
Contouring: Definition of contouring, contour interval, characteristics of contours, direct and
indirect methods of contouring, interpolationof contours, contour gradient, uses of contour maps.
Theodolite surveying: Types of theodolites, temporary and permanent adjustments, measurement of
horizontal and vertical angles, theodolite traversing, included angles from bearings, fundamental lines
and desired relations, errors in theodolite work, electronic theodolite, plotting a traverse, latitude and
departure of lines, consecutive and independent coordinates, closing error, balancing a traverse,
Gale’s traverse table, omitted measurements, calculation of area.
Modern surveying instruments:Electronic Distance Measuring (EDM) equipment, totalstation.
Remote sensing: Introduction and basic concepts, spectral reflectance of ground features, data
acquisition and interpretation, applications of remote sensing for resources mapping, Global
Positioning System and Geographic Information System.
Aerial photogrammetry: principles, computation of scale and distance between points, relief
displacement, measurement of the height of different objects, ground control, flight planning.
4. Course Outcome
CO1: Understand different procedures to survey areas with varied topography.
CO2: Understand the basics of electronic distance measurement instruments and
remote sensing.
CO3: Carry out surveying and record the surveying data for an area using survey
instruments.
CO4: Prepare a plan or map of an area surveyed.
CO5: Analyse and appropriately distribute the survey errors.
5. Books
1. Subramanian, R., Surveying and Levelling, Oxford (2012).
2. Punmia, B.C., Jain, A. K. and Jain, A. K., Surveying Vol. I and II, Laxmi
Publications (2016).
3. Basak, N. N., Surveying and Levelling, Tata McGraw Hill (1994).
4. Agor, R., Surveying, Khanna Publishers (1982).
5. Venkatramaiah, C., A Text Book of Surveying, Universities Press (1996).
6. Outline
• Introduction
• Objective
• Applications
• Classification of surveying
• Principles of surveying
• Plans and maps
• Scales
• Example problem
7. Introduction
Surveying is an art of determining the relative positions of various points of interest
on, above or below the surface of the earth by means of direct or indirect
measurement of horizontal and vertical distances, angles and taking the details of
the points.
Objective
• The primary objective of surveying is to prepare a plan or map to show the relative
position of the objects on the surface of the earth.
• It is also used to determine the areas, volumes and other related quantities.
8. Applications
Surveying is useful in various applications
• To prepare plan required for the construction of buildings, bridges,
railway lines, water supply and irrigation schemes etc.
• To prepare a topographical map which shows the hills, valleys, rivers,
towns, forests etc. of a country.
• To prepare a contour map to help in finding possible route of roads,
railways etc.
9. Classification of surveying
Two primary divisions of surveying are:
• Plane surveying and,
• Geodetic surveying
• Plane surveying is that type of surveying in which the mean surface of
the earth is considered as a plane and the spheroidal shape is
neglected. The assumption seem to be reasonable, e.g. for 12
kilometres long distance error is only 1 cm.
• Geodetic surveying considers the curvature of the earth. The objective
of this type of survey is to determine the precise position on the
surface of the earth, of a system of widely distant points. Geodetic
surveying is carried out over an area exceeding 250 km2.
11. Other classifications
• Classification based on nature of field survey:
• Land surveying
• Marine or hydrographic survey
• Astronomical survey
• Classification based on objective:
• Engineering survey
• Military survey
• Geological survey
• Archaeological survey
12. Principles of surveying
The general principles of surveying are:
1. Working from the whole to the part, and
2. To locate a new point by at least two measurements from the
reference points
• According to the first principle, the whole area is first enclosed by
main stations and main survey lines. The area is then divided into a
number of parts by forming Well-conditioned triangles. The purpose
of this process of working is to prevent accumulation of error.
14. A triangle is said to be well conditioned triangle when no angle in it is
less than 30˚ and not greater than 120˚. An equilateral triangle is the best
well-conditioned triangle (Ideal Triangle) possible.
Well conditioned triangle
60˚
60˚
60˚ 85˚
50˚
45˚ 140˚
20˚
20˚
Well-conditioned triangles Ill-conditioned triangle
15. Principles of surveying Contd.
• According to the second principle, the new stations should always be
fixed by at least two measurements from fixed reference points. The
measurements can be combination of linear and angular
measurements.
Let, P and Q be the reference
points on the ground. Any
other point, such as R, can be
located by any of the methods
in Fig. 1
Fig. 1
16. Plans and maps
• A plan is the graphical representation, to some scale, of the features
on, near or below the surface of the earth as projected on a horizontal
plane which is represented by plane of the paper on which the plan is
drawn.
• The representation is called a map if the scale is small while it is called
a plan if the scale is large.
• On a plan, generally, only horizontal distances are shown. On a
topographic map, however, the vertical distances are also represented
by contour lines or other systems.
18. Scales
The area that is surveyed is vast and, therefore, plans are made to some
scale. Scale is the fixed ratio that every distance on the plan bears with
the corresponding distance on the ground.
Scale can be represented by the following methods:
a. One cm on the plan represents some whole number of metres on the ground.
Such as: 1 cm = 10 m etc. This type of scale is called Engineer's Scale.
b. One unit of length on the plan represents some number of same units of
length on the ground, such as 1/1000 etc. This ratio of map distance to the
corresponding ground distance is independent of units of measurement and
is called Representative Fraction (R. F.).
20. Error due to wrong scale
If the length of a line existing on a plan or a map is determined by
means of measurement with a wrong scale, the obtained length will be
incorrect.
• The true or correct length of the line is given by the following relation:
• Similarly, if the area of a map or plan is calculated with the help of
using a wrong scale, the correct area is given by:
R. F. of wrong scale
Correct length = Measured length
R. F. of correct scale
2
R. F. of wrong scale
Correct area = Calculated area
R. F. of correct scale
21. Shrunk scale
If a graphical scale is not drawn on the plan and the sheet on which the
plan is drawn shrinks due to variations in the atmospheric conditions, it
becomes essential to find the shrunk scale of the plan.
• The shrinkage ratio or shrinkage factor is then equal to the ratio of the
shrunk length to the actual length. i.e.
• The shrunk scale is then given by:
Shrunk scale = Shrinkage factor × Original scale
Shrunk length
Shrinkage factor =
Original length
22. Example problem
An old map was plotted to a scale of 20 m to 1 cm. Over the years, the
map has been shrinking, and a line originally 20 cm is only 19.5 cm
long at present.
i. Calculate the shrunk scale.
ii. If the present area of the map measured by a planimeter is 50 cm2,
find the true area of the land surveyed.
23. Solution
1 cm 1 cm 1
R. F. =
20 m 20 100 cm 2000
= =
Shrunk length 19.5
Shrinkage factor = 0.975
Original length 20
= =
Shrunk scale = Shrinkage factor × Original scale
= 0.975 ×
1 1
2000 2051
=
Actual area = ( )
2 2 2
50 2051 210330050 cm 21,033 m
= =
24. In the next class
Linear Measurements ~ Chaining
