Canadian Forest Service Publications
A comparison of existing models for dbh estimation from large-scale photos. 1989. Hall, R.J.; Morton, R.T.; Nesby, R.K. Forestry Chronicle 65(2): 114-120.
Available from: Northern Forestry Centre
Catalog ID: 11188
The performance of 12 diameter prediction models suggested in the literature was studied in a controlled operational test. These models were linear and logarithmic transformations of tree height and/or crown area and were analyzed for white spruce, lodgepole pine, and trembling aspen and balsam poplar combined. Overall, all models were statistically significant, with differences due to variations in species and model form. Although simpler models may be adequate depending on operational objectives, two models emerged as deserving further investigation. It was unclear whether both tree height and crown area were needed as predictors of tree dbh for all species. Tree height was more highly correlated with dbh than crown area for all species except lodgepole pine. Measuring both tree height and crown area in comparison with tree height alone, however, increases measurement cost substantially from $10.29 to $17.50 per plot (1987 dollars).