期刊名称：ISPRS Annals of the Photogrammetry, Remote Sensing and Spatial Information Sciences
印刷版ISSN：2194-9042
电子版ISSN：2194-9050
出版年度：1992
卷号：XXIX Part B7
页码：635-642
出版社：Copernicus Publications
摘要：The Forest I nventory and Analysis unit of the USDA Southern Forest ExperimentStation is charged with conducting continuous inventories of the forest resources ofthe USA's Midsouth Region. One new approach for estimating the density of foreststands involves the derivation of a technique for obtaining stand density from aerialphotographs based on the principles of selection with probability proportional tosize. This is accomplished by the development and use of an aerial-photo anglegaugethat is used in a procedure very similar to the ground point-samplingtechnique developed by Bitterl ich (1948).Data from the 1984 forest inventory of Louisiana and the 1988 forest inventory ofTennessee were obtained; the relationship between diameter at breast height (dbh)and crown diameter was investigated and correlations and models analyzed.Sampling angles were calculated and dimensions of aerial-photo angle-gauges weredetermined and the gauges were constructed. Areas were inventoried using boththe photo-based method and the standard ground-based method.Though promising in theory, the angle-gauge sampling technique resulted in a forestinventory that vastly underestimated the number of trees, total volume, and totalbasal area of the forest resource. Problems encountered included an omission ofboth small diameter trees and large diameter trees from the tall ied sample trees.
