Differential leveling is a surveying technique whereby the difference in elevation of two stations is computed by comparing the height of a level horizontal line passing above the stations. Originally, the horizontal line was established by placing an accurately leveled telescope approximately midway between the two points and using it to read a calibrated rod held vertically on each point. The process was repeated in stages to transfer a known elevation to an unknown elevation.

differential leveling (last edited 2009-03-21 21:03:19 by localhost)