Glossary of Module 10 |
Centring : The process involved in setting of a plane table above a ground station in such a way that the plotted position of station lies exaclly over the station. Orientation : The process involved in aligning a plane table by rotating it in the horizontal plane in such a way that all the plotted lines are parallel to the corresponding lines on the ground. Backsight : It is the sight taken from a plane table station to another station whose position had already been plotted. Foresight : It is the sight taken from a plane table station to another station whose position is yet to be located. Radiation : A method of locating field objects by drawing a radial line from the plane table station towards that point along the fiducial edge of alidade. Intersection : A method of locating a point by the intersection of the two rays drawn from two different stations to the same object. Resection : This is a method of locating the station occupied by the plane table when the position of that station had not been previously plotted from other stations. Pivoting of alidade : The alidade is kept on the drawing sheet, with the zero mark of the fiducial edge set on the station point. Resector : A line drawn after bisecting an object with alidade pivoted to its plotted position. Great Circle : The imaginary circle passing throught the three points in the field of the three point problem. Great Triangle : The imaginary triangle with vertices at the three point (in the field) of three point problem. |