Basal Area application is designed for simple basal area calculation by using Bitterlich method like as Relascope survey. Step 1 Take forest photos by 360 degree camera, and saved by Equi-rectangular format. Step 2 Copy the photos to smartphone Step 3 Open the file from "Basal Area" application Step 4 Compare the trunk size (1.3m height) of trees with center red circle Step 5 Tap "1.0" an case of the tree is bigger than red circle -> red mark Tap "1.0" an case of the tree is bigger