introduction
Now that the basic theory of differential leveling has been illustrated, it is time to define the terms that have been presented and look at the detailed procedure that should be followed to perform leveling accurately.
Quick Description Of The Leveling Process
As can be seen, leveling is a very simple process of taking a backsight and a foresight from an instrument setup and repeating it over and over to transfer an elevation from one point to another. Indeed, it is simple, but in order to perform it accurately and to achieve the precision required, much attention must be paid to the details. The following step-by-step description of the process of leveling attempts to cover the details that must be followed. See the Section, Differential Leveling, on Page 7-22.
7-22
Set up instrument and level it.
Step 1
Hold the rod on known elevation point and record to the nearest 0.01 ft. the backsight reading, with the rod person holding the level rod plumb over the point.
Step 2
Advance the rod person to the turning point (an equal distance from the instrument as the backsight station).
Step 3
Hold the rod on the turning point and read and record the foresight reading.
Step 4
Step 5
Step 6
Repeat previous steps until the elevation of the designated point has been determined.
Close the loop by repeating the process back to the benchmark.
