Advanced surveying (22301) MSBTE curriculum I scheme Chapetr1- Plane table surveying

1. PLANE TABLE SURVEYING
( 8 marks)

3. 1a.Explain the functions
and use of given
accessories of plane table
survey
1d.Compare the given two
methods of doing plane
table survey
1b.Describe the method of
orienting the plane table in
given situation
1c.Select the method of
plane tabling for given
situation
1.Use plane table survey to
prepare of 5 sided closed
traverse by Radiation
method
3.Use plane table survey to
prepare plans and locate
details by intersection
method
4.Use plane table survey to
prepare plans and locate
details by traversing
method
a. Prepare plans using Plane
Table Surveys
5.Use plane table to carry
out Survey Project for
closed traverse for
minimum 5 sides around a
buildings
UO’s PrO’s
CO’s

4. Introduction
Plane tabeling is graphical method of surveying.
Here, the field work and plotting are done simultaneously
Such survey does not involve the use of field book

5. Suitability
It is mainly suitable for filling interior details when traversing
is done by theodolite
 Sometimes traversing by plane table may also be done
But this survey is recommended for the work where great
accuracy is not required

6. Principle
The principle of plane tabeling is parallelism, meaning that rays
drawn from station to the object on the paper are parallel to
the lines form the station to the object on ground.
The relative positions of the objects on the ground are
represented by their plotted positions on the paper and lie on
respective rays.
 The table is always placed parallel at each successive station to
the position it occupied at starting station

7. Accessories of plane table
Accessories
Plane table
Alidade
Spirit level
Trough compass
U fork with plumb
bob
Plane alidade
Telescopic
alidade

8. Plane table
It is a drawing board of
750X600 mm made of well
seasoned wood like teak, pine
etc. The top surface of it is well
levelled. The bottom surface
consists of threaded circular
plate for fixing the tripod on
the tripod stand by wing nut.
Function:
It is meant for fixing drawing
sheet over it.

9. Plane table

10. Alidade
a)Plain alidade:
It consists of metal or wooden
ruler of length about 50 cm.
One pf its edge is beveled and is
known as fiducial edge. It consists
of two vanes at both ends. One is
called as ‘Object vane’ which
carries ‘Horse hair’ and other is
called ‘Sight vane’ which has a slit.

12. Alidade
b) Telescopic alidade:
It consists of telescope meant for
inclined sight or sighting distant
object clearly. This alidade does
not have vanes but is provided
with fiducial edge.
Function of alidade:
The function of alidade is to sight
object. The ray should be drawn
along fiducial edge of alidade.

14. Spirit level
Spirit level is a small metal tube
consists of a small bubble of
spirit. The bubble is visible on the
top along a graduated glass tube.
Function:
The spirit level is meant for
levelling the plane table.

15. Trough compass
Trough compass is rectangular box
made of non magnetic metal
containing a magnetic needle pivoted
at the center. It has 0 mark at both
ends to locate N-S directions.
Function:
1.It is meant to mark north direction
on drawing sheet
2.It is used for orientation of plane
table

17. U-fork with plumb bob
It is a metal strip bent in a shape of U(
hair pin) having equal arm lengths. The
top arm is pointed and a bottom arm
carries a hook for suspending a plumb
bob.
Function:
This is meant for centering the table
over station.

19. Setting of plane table
Fixing the table on tripod stand
Levelling the table
Centering the table
Marking the north line
Orientation

20. Orientation
Orientation
By magnetic
needle
By
backsighting

21. Orientation by magnetic needle

22. Orientation by backsighting

23. Methods of plane table surveying
Methodsofplanetable
surveying
Radiation method
Intersection
method
Traversing

24. Radiation Method

25. Intersection Method

26. Traversing Method

27. Merits/Advantages of plane table surveying
It is most rapid method of surveying
There is no need of field book thus problem of mistakes in
booking field notes does not arise
Plotted work can be compared with actual object
regardless of weather or not they are properly represented
There is no possibility of overlooking any important object
There is no possibility of overlooking any measurements as
plotting is done in field

28. Merits/Advantages of plane table surveying
Irregular objects can be represented accurately
It is suitable in magnetic areas
The map can be prepared easily and does not require any great
skill
Errors in measurement and plotting can be detected by check
lines
Inaccessible points can be easily located by intersection

29. Demerits/Disadvantages of plane table surveying
The plane table is not suitable for accurate work as the fitting
arrangement is not perfect
Plane table surveying is not suitable in wet climate, in the rainy season,
on foggy mornings and in windy weathers
The number of accessories required in such survey are large and they are
likely to be lost
The instrument is very heavy and difficult to carry
The map cannot be replotted to a different scale as there is no field book

30. THANK YOU!