Abstract Plot volume estimates were made from measurements of individual trees on large-scale 1:1,200, 70 mm air photographs. Species, total height, crown area, and where possible stem diameter of each tree were determined on 1/5-acre photo plots. Gross cubic volume of each tree was obtained from form-class volume tables entered with photo height and dbh, the latter provided either by regression equations of dbh on the combined photo variables crown area and height or direct photo measurements of dbh. Plot volume estimates were compiled and accuracy tested against plot volumes determined on the basis of field measurements. Accuracy was ± 15 percent of plot volume with 95 percent confidence. Bias was — 6.9 percent of total volume of 15 test plots.
Aldred et al. (Fri,) studied this question.