Abstract Cubic-foot volumes obtained from Spiegel Relaskop measurements of 25 shortleaf pines were only 1.6 percent higher than comparable volumes based on Barr and Stroud measurements. Differences between volume estimates with the two dendrometers were related to tree size; the greatest difference occurred in the 6-inch diameter class. Observer differences were larger with the Spiegel Relaskop (3.7 percent) than with the Barr and Stroud (0.5 percent). Separate analyses with Speigel Relaskop data indicate that 4-inch taper step measurements overestimate volume by 1.3 percent as compared to 2-inch taper steps and that the subneiloid algorithm is more accurate than the conoid or paraboloid for volume determination of the whole tree.
Yocom et al. (Mon,) studied this question.