Variable Plot Cruising: A Short-Cut Slope Correction Method

In variable plot cruising it has been the practice, when prisms or angle gauges are being used, either to make multiple corrections taking account of the slope to each tree, or to use a secant multiplier for enlarging uncorrected slope circles. Error is encountered when the secant of the average slope at each point is used, and loss of control of the sampling intensity occurs even when mathematical error is overcome by use of the secant of the maximum slope at each point. With the described method only one slope correction need be made at each point. Methods of field implementation are suggested, and a table of instrument settings is provided.