Relascope / Angle Gauge for Forestry (Metric)

thingiverse

Tool to estimate the volume forest per hectare, both by calculating the basal area and height of the trees. I designed it after my own liking as a two part objects to reduce its size and to add the possibility to carry it around you neck as the rope is tied in a loop. The relascope relies on the 50 cm distance to 1cm opening ratio making the basal area equal to that of each counted tree(i did the derivation if anyone is interested). Note that you need about 1.1m rope/cord to get to 50cm knots included. Formula is as follows: volumeforest [m3/hectare] = K * h/2 * N, were K is a constant depending on the tree spices, h is the average height of the trees and N is the basal area estimated using this tool. The height of the trees, h, can be estimated by combining the tool to a 45 degree triangle with 10cm sides. Hold the triangle up to you eye and distance yourself so that the top and trunk of the tree is aligned within the triangle, add your height at eye-level and distance to the tree and you got its height. Simple trigonometry at its best.