Subject :- 20CE303 Surveying and

Geomatics

Mr. V. Yogeshwaran
Assistant Professor
Department of Civil Engineering
Definitions, Classifications – Basic
Principles
Lecture videos & E-books

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 Definition
 Surveying is the art of and science of determining the
relative positions of various points or stations on the
surface of the earth by measuring the horizontal and
vertical distances, angles, and taking the details of these
points and by preparing a map or plan to any suitable
scale.
 Surveying is defined as the science of making measurements of the earth

specifically the surface of the earth. This is being carried out by finding the spatial

location (relative / absolute) of points on or near the surface of the earth.

 Different methods and instruments are being used to facilitate the work of

surveying.

The primary aims of field surveying are :

 to measure the Horizontal distance between points.

 to measure the Vertical elevation between points.

 to find out the Relative direction of lines by measuring horizontal angles with

reference to any arbitrary direction and

 to find out Absolute direction by measuring horizontal angles with reference to a

fixed direction.
 OBJECTIVES OF SURVEYING
• The object of surveying is to prepare a map or plan to show
the relative positions of the objects on the surface of the earth.
• The map or plan is drawn to some suitable scale.
• It also shows boundaries of districts, states, and countries too.
• It also includes details of different engineering features such
as buildings, roads, railways, dams, canals etc.
 COMMON THINGS TO KNOW
 Before plan topography of the site and boundaries must be
determined.
 In survey horizontal distances are measured.

 What is the purpose of survey?

The primary object 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.
 PLAN
 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.
 The horizontal plane is represented by plane of drawing sheets
on which the plan is drawn to some scale, however the surface
of the earth is curved it cannot be truly represented on a plane
without distortion.
 MAP
 If the scale of the graphical projection on a horizontal plane
is small then it is called as map. Whereas the horizontal
projection is large then it is plan.
 On plan, generally only horizontal distances and directions
or angles are shown. On topographical map, however the
vertical distances (elevations) are also represented by
contour lines.
Objective of Surveying
TOPOGRAPHICAL MAPS
GEOLOGICAL MAP
ARCHAEOLOGICAL MAP
CONTOUR MAP
USES OF SURVEYING

 To prepare a contour map to know the topography of the

area to find out the best possible site for roads, railways,
bridges, reservoirs, canals, etc.
 Surveying is also used to prepare military map,
geological map, archaeological map etc.
 For setting out work and transferring details from the
map on the ground.
The surveying may be used for following purposes:
 To prepare a topographical map which shows hills, valleys,
rivers, forests, villages, towns etc.
 To prepare a cadastral map which shows the boundaries of
fields, plots, houses and other properties..
 To prepare an engineering map which shows the position of
engineering works such as buildings, roads, railways, dams,
canals.
CLASSIFICATION OF SURVEYING
• Primary Divisions of Surveying

• We know that the shape of the earth is spheroidal. Thus the

surface is obviously curved. Surveying is primarily divided into
two types considering the curvature of the earth’s surface.
• Plane Surveying

• Geodetic Surveying
• Plain Surveying
• The plain surveying is that type of surveying in which earth
surface is considered as a plane and the curvature of the
earth is ignored. In such surveying a line joining any two
stations is considered to be straight. The triangle formed by
any three points is considered as a plane triangle, and the
angles of the triangle are considered as plain angles.
• Surveying is carried out for a small area of less than 250 km2.
It is carried out by local or state agencies like R & B
department, Irrigation department, Railway department.
Plain Surveying
• Geodetic Surveying
• The geodetic Surveying is that type of surveying in which the
curvature of the earth is taken into account. It is generally
extended over larger areas. The line joining any two stations is
considered as curved line. The triangle formed by any three
points is considered to be spherical and the angles of the triangle
are considered to be spherical angles. Geodetic surveying is
conducted by the survey of India Department and is carried out
for a larger area exceeding 250 km2
Geodetic Surveying
Plain Surveying Vs Geodetic Surveying
No. Plain Surveying Geodetic Surveying
1 The earth surface is The earth surface is considered as
considered as plain Surface. Curved Surface.

2. The Curvature of the earth is The curvature of earth is taken into

ignored account.
3 Line joining any two stations is The line joining any two stations is
considered to be straight considered as spherical.
4. The triangle formed by any The Triangle formed by any three
three points is considered as points is considered as spherical.
plain
5. The angles of triangle are The angles of the triangle are
considered as plain angles. considered as spherical angles.
6. Carried out for a small area < Carried out for a small area > 250 km2
250 km2
 Fundamental Principles of Surveying
Two basic principles of surveying are:
• Always work from whole to the part, and
• To locate a new station by at least two measurements
(Linear or angular) from fixed reference points.
Always work from whole to the part:

• According to the first principle, the whole survey area is first enclosed by

main stations (i.e.. Control stations) and main survey lines. The area is then

divided into a number of divisions by forming well conditioned triangles.

• The main survey lines are measured very accurately with precise survey

instruments. The remaining sides of the triangle are measured. The purpose

of this method of working is to control accumulation of errors. During

measurement, if there is any error, then it will not affect the whole work, but

if the reverse process is followed then the minor error in measurement will

be magnified.
Work from Whole to the Part
To locate a new station

According to the second principle the points are located by

linear or angular measurement or by both in surveying. If two
control points are established first, then a new station can be
located by linear measurement. Let A & B are control points,
a new point C can be established.
• Following are the methods of locating point C from such reference points A

& B.

• The distance AB can be measured accurately and the relative positions of

the point can be then plotted on the sheet to some scale.

• (a) Taking linear measurement from A and B for C.

• (b) Taking linear measurement of perpendicular from D to C.

• (c) Taking one linear measurement from B and one angular measurement

as ∕ ABC

• Taking two angular measurement at A & B as angles / CAB and / ABC.

• Taking one angle at B as / ABC and one linear measurement from A as AC.
CLASSIFICATION OF SURVEYING

Based on instrument
Based on methods
Based on object

Based on nature of field

 Secondary Surveying

ON
Chain Surveying Compass Surveying
THE
BASIS
Theodolite
Plane Table OF Surveying
Surveying INSTRUMENTS

Photographic
Modern Surveying
Surveying
Classification based on Instrument

1. Chain Survey : This is the simplest type of surveying in which

only linear measurements are made with a chain or a tape.
2. Compass Survey : In compass survey, the angles are
measured with the help of a magnetic compass.
3. Plane table Survey: It is graphical method of surveying in
which field works and plotting both are done simultaneously.
4. Theodolite Survey : In theodolite survey, the horizontal
angles are measured with a theodolite more precisely
than compass and the linear measurements are made
with a chain or a tape.

5. Photogrammatic Survey : This type of survey is used to

determine the vertical distances indirectly.

6. Modern Survey : In this type of survey, measurements are

made with the instruments like EDM & Total station.
Chain Survey
Compass Survey
Theodolite Survey
Photogrammetric Survey
Triangulation ON
THE
BASIS
OF
METHODS
Traversing
 Classification based on Methods
1. Triangulation : Triangulation is a basic method of surveying.
When the area to be survey is large, triangulation is adopted

2. Traversing : A traverse is a circuit of survey lines. It may be

open or closed. When the linear measurement are done
with a chain and a tape and the directions or horizontal
angles are measured with a compass or a theodolite
respectively, the survey is called traversing.
Triangulation
Traversing
Mine Surveying ON Archeological
THE Surveying
BASIS
OF
NATURE OF OBJECT
Geological
Military Surveying
Surveying
 Classification based on OBJECT

1. Geological Survey : In this both surface and subsurface surveying are

conducted to locate different minerals and rocks.

2. Mine Survey : Mine survey include both surface and underground surveys. It is

conducted for the exploration of mineral deposits and to guide tunneling and

other operations associated with mining.

3. Archeological Survey : It is conducted to locate relics of antiquity, civilization,

kingdoms, forts, temples, etc.

4. Military Survey : It has a very important and critical application in the military.

Aerial surveys are conducted for this purpose.

 Geological Survey

Geological Maps

Hydrological Maps
Mine Survey
Archaeological Survey
Military Survey
Land Surveying ON Marine
THE Surveying
BASIS
OF
NATURE OF FIELD
Astronomical Aerial
Surveying Surveying
 Classification based on Nature of Field
1. Land Survey : Land survey is done on land to prepare plans
and maps of a given area.
2. Hydrographic Survey : This survey is conducted on or near
the body of water such as lake, river, coastal area.
3. Astronomic Survey : The surveys are conducted for the
determination of latitudes, longitudes, azimuths, local time,
etc.
4. Aerial Survey : An aerial survey is conducted from aircraft.
Aerial cameras take photographs of the surface of the earth
in overlapping strips of land.
Land Survey
 Hydrological Surveying

Hydrological Maps
Hydrological Maps
Astronomical Survey
Aerial Survey
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 Review question

1. Find the distance between two invisible stations (from Sri

Krishna Temple to Admin Block in SKCET) using direct &
indirect ranging methods. Establish the intermediate points
as per the ground conditions. Use Chain, Cross staff, Pegs
and arrows for fixing the intermediate points, marking and
offset purposes.