Intersection Method, Surveying and Levelling | Surveying and Levelling Notes- Agricultural Engg - Agricultural Engineering PDF Download

INTERSECTION METHOD
In this method the plane table is shifted to a known distance in a particular direction marked on the ground and the line of sights are drawn to make intersection of the radial lines already drawn from the first set up of the instrument.

PROCEDURE

• Select two points P and Q such that the points (building corners) to be plotted are visible from their stations.
• Set the table on P and locate on the sheet.
• Pivot on P bisect Q draw a ray.
• Measure the distance PQ and locate Q on the sheet to a convenient scale.
• Now PQ is known as the base line.
• Pivot ‘P’ bisects the inaccessible objects A and B (building corners) and draw rays.
• Shift the table to ‘A’ such that P is over Q and do temporary adjustments.
• Place the alidade along QP and the rotate the table till P is bisected, clamp table.
• Pivot on Q bisect the objects A and B and draw rays.
• The instruction of rays drawn from P and Q will give the points A and B.
• To check the accuracy measured AB and compare with plotted distance AB.
• The same procedure is applied for other features of the campus. each point is bisected from two stations.