A procedure was developed for surveying cross sections using a sag tape with unequal end elevations. The procedure is as accurate as traditional engineer's level surveys, is faster and easier, and can be programed for a digital computer by following the flow diagram which is provided.
Ray, Gary A.; Megahan, Walter F. 1979. Measuring cross sections using a sag tape: a generalized procedure. Gen. Tech. Rep. INT-GTR-47. Ogden, UT: U.S. Department of Agriculture, Forest Service, Intermountain Forest and Range Experiment Station. 12 p.