Making Tree Height Observations
With the Trees observation, users locate, measure the height of, and take a photograph of trees. Each GLOBE Observer tree height observation includes finding a tree or trees and taking tree height measurements using the smartphone cameras and the Trees tool built-in angle measuring techniques.
In the introduction, the user will be asked to submit their height, from this, the Trees tool will estimate stride length and height of phone of the user. The user will first choose a tree and find a spot 7-15 meters away from the tree that allows a clear view of the top and bottom of the tree. The app then guides the user to use their smartphones to align to the bottom of the tree and then to the top of the tree, then walk to the base of the tree, counting steps, and entering the number of steps into the app. At the base of the tree, the user will measure the latitude and longitude.
Once the user becomes familiar how the app works, through a required, short tutorial, the user will be able to choose to take observations in Expert Mode. Included in the app is an optional measurement of the tree circumference. The only additional equipment you will need is a tape measure for measuring the circumference of the tree.
Finally, before the user submits an observation, they will be asked to review and make any changes to the measurements.
Trees measured should be at least 5m (16.4ft) tall;
Trees measured should be isolated trees or the tallest trees in a large grouping of trees