Download Geodetic Surveying

Division Of Surveying
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Rampurwala Taher Z.
Panchal Deep S.
Shah Akash K.
Patel Apurv K.
Rathod Hardipsinh B.
Introduction
• The approximate shape of the earth can best be defined as
an oblate tri-axial ovaloid. But, most of the civil
engineering works, concern only with a small portion of the
earth which seems to be a plane surface. Thus, based upon
the consideration of the shape of the earth, surveying is
broadly divided into two types.
• Plane Surveying
• Geodetic Surveying
Scope and Use of Plane surveying
• Plane surveys are carried out of engineering projects on
sufficiently large scale to determine relative positions
of individual features of the earth surface.
• Plane surveys are used for the layout of highways,
railways, canals, fixing boundary pillars, construction
of bridges, factories etc.
• The scope and use of plane surveys is very wide.
Division of Plane Surveying
• Plane surveying can be divided in the
following ways.
• Chain Surveying
• Traverse Surveying
• Plane Tabel Surveying
• Ordinary Leveling
Chain Surveying
• Chain surveying is the simplex type of
surveying in which the area to be surveyed is
divided into a number of triangles. The length
of the sides are measured and the interior
details are recorded. The whole area is then
plotted on a suitable scale to produce a map.
Chain Surveying
Traverse Surveying
• Traverse surveying is a type of surveying in
which the plot of land to be surveyed is enclosed
by a series of straight lines making angles with
one another. The length of the lines and the angles
are measured and plotted with all interior details
on a drawing sheet to a suitable scale to produce a
map.
Diagram of an
open traverse
Diagram of a
closed traverse
Plane Table Surveying
• Plane table is a graphical method of surveying
in which the field works and the plotting is
done simultaneously. It is particularly adopting
in small mapping. Plane table surveying is
used for locating the field computation of area
of field.
Plane Table Surveying
Merits
• It is most suitable for preparing small scale map or surveying small
area.
• It is most rapid method.
• Field book is not necessary.
• No great skill is required for satisfactory map.
• It is particularly suitable for magnetic area where prismatic compass
is not reliable.
• Contour and irregular object may be represented accurately.
• It is less costly.
Demerits
• Plane Table Essentially a tropical instruments.
• It is not suitable to work in wet climate.
• There are several accessories to be carried out
and therefore they are likely to be lost.
• It is not suitable for accurate work.
Geodetic Surveying
• Geodetic surveying measures all elevations from a level
surface, and because all instruments use a straight
reference plane, this requires all instrument readings of
elevation to be adjust for the curvature of the earth.
Geodetic surveys are used when a high degree of
accuracy is needed and when the survey will cover long
distances or a large area.
Use of Geodetic Surveying :
• Engineering purposes: The engineers uses Geodetic
Surveying for finding out the exact location of the
concerned point or area. Latitudes and longitudes are
needed for any engineering constructions.
• Construction purposes: The builders used Geodetic
Surveying for finding out the direction of the buildings
or their exact location for vaastu shastra.
• Land Surveying and assessment: The vertical elevation
and the horzontal attributes , the latitude and longitudes
of the area surveyed are found out through Geodetic
Surveying .
The End
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