GRAPHICAL METHOD
Plane Table Survey:
Plane Table Survey is a method of Surveying in which field work and the office work are
done simultaneously. It is also known as the graphical method of Surveying. A manuscript
map is made in the field and the topographic details can be filled in later.
Significance and Applications
This is the easiest method in plane tabling. It is used when:
All the details are visible and accessible from one instrument station
The ground is level and smooth
Distances are so small that can be measured with single tape
It is simple and cheaper than theodolite survey
List of Instruments used in Surveying:
(1) Plane Table
(2) Alidade
(3) Plumbing fork and Plumb bob
(4) Spirit Level
(5) Chain or Tape
(6) Rain roof cover for the plane table
(7) Compass
(8) Ranging Rods
(9) Drawing Sheets
(10) Drawing equipment.
, Plane-Table survey
Procedure: To do the plane tabling one has to follow the following procedure at every plane
table set-up:
(a) Fixing the plane table to the tripod stand
(b) Setting up and temporary adjustments:
1. Leveling the plane table with the help of spirit level
2. Centering with the help of plumbing fork
3. Orientation by trough compass or by back sighting
(c) Sighting the points with the help of Alidad
Methods of plane tabling:
1. For locating details:
(a) Radiation Method: A ray is drawn towards the point with the help of the Alidade. With
the help of Chain or Tape the horizontal distance is measured from the Plane Table to the
point and this point is located on the sheet by plotting it into the scale of the map.
(b) Intersection Method: In this method two instrument stations are used but no chain or
tape is required. Intersecting rays are drawn from these two stations whose location is already
plotted (by measuring the distance between them), the point of intersection is the location of
the point.
2. For locating Plane Table Stations:
Plane Table Survey:
Plane Table Survey is a method of Surveying in which field work and the office work are
done simultaneously. It is also known as the graphical method of Surveying. A manuscript
map is made in the field and the topographic details can be filled in later.
Significance and Applications
This is the easiest method in plane tabling. It is used when:
All the details are visible and accessible from one instrument station
The ground is level and smooth
Distances are so small that can be measured with single tape
It is simple and cheaper than theodolite survey
List of Instruments used in Surveying:
(1) Plane Table
(2) Alidade
(3) Plumbing fork and Plumb bob
(4) Spirit Level
(5) Chain or Tape
(6) Rain roof cover for the plane table
(7) Compass
(8) Ranging Rods
(9) Drawing Sheets
(10) Drawing equipment.
, Plane-Table survey
Procedure: To do the plane tabling one has to follow the following procedure at every plane
table set-up:
(a) Fixing the plane table to the tripod stand
(b) Setting up and temporary adjustments:
1. Leveling the plane table with the help of spirit level
2. Centering with the help of plumbing fork
3. Orientation by trough compass or by back sighting
(c) Sighting the points with the help of Alidad
Methods of plane tabling:
1. For locating details:
(a) Radiation Method: A ray is drawn towards the point with the help of the Alidade. With
the help of Chain or Tape the horizontal distance is measured from the Plane Table to the
point and this point is located on the sheet by plotting it into the scale of the map.
(b) Intersection Method: In this method two instrument stations are used but no chain or
tape is required. Intersecting rays are drawn from these two stations whose location is already
plotted (by measuring the distance between them), the point of intersection is the location of
the point.
2. For locating Plane Table Stations:
