Plane Table Surveying

Plane table surveying method is a method of surveying where, the plan position of individual features on the surface of the earth . In this method field observation and plotting are continuing simultaneously. The following operations are followed at each plane table surveying; Levelling, Centering and Orientation.

Method of Plane Table surveying

The following methods are adopted for a plane table surveying.

• Radiation Method – In this method , plane table is setup at any commanding station. Now detailed points are plotted on the radiating lines which are basically drawn from the each location of the plane table station, after reducing the respective ground distances on the desired scale of the pointed map.
• Intersection Method – In this method ,a firm base line of convenient length is plotted on the scale of survey and location of any other detail point, is determined by drawing rays from each end station after proper orientation of the table.
• Traversing Method – In this method , a series of connected straight lines each joining two stations on the ground, is established by setting up the plane table at each successive station, drawing a foresight to next station and plotting its position by measuring the distance directly between the two stations.
• Resection Method – In this method the location of the station occupied by the plane table , is obtained by means of drawing rays from the stations whose location has already been plotted on the paper. Resection may be done with the help of two points and three points.
1. Two point Problem – After finding the location of the station occupied by the table on the paper , which is actually sighting to two well defined points whose locations have previously been plotted on the paper , is known as two point problem.
2. Three point problem – After fixing the location of station which is occupied by a lane table on the paper e sighting to three well defined points whose positions have previously been plotted on the sheet, is known as three point problem.