A slope distance between two points P and Q is measure using a laser EDM, giving a corrected slope distance of 13,978.811m. The elevation of the lower point P is 470.381m. Reciprocal vertical angles are measured at P =+2o12’15”, and at Q =-2o19’15”. Assume the instrument and target are at the same height above the ground at the two stations.
What is the elevation of point Q?
Use the two approach
(a) using only the single vertical angles on both
locations and applying the correction for curvature and refraction and obtain the average of the two, and
(b) using the average obtained by both vertical angles with applying the curvature and refraction correction.