What is "relascope"

n. An instrument for forest inventory, consisting of a sight hole and marked scales, primarily used to find the height, basal area and diameter of a tree anywhere along the bole.

The relascope, invented by Walter Bitterlich, is a multi-use instrument for forest inventory. It is primarily used to find height of a tree, basal area of a tree and diameter of a tree anywhere along the bole. This instrument is used mostly for applications involving variable radius sample plots in a forest survey.