Healthy forests play a crucial role in Earth’s ecosystem as growing trees take up carbon from the atmosphere. NASA satellites and airborne missions study forests to see how carbon moves through ecosystems. Adding in height measurements to more general observations of land cover gives a more complete, three-dimensional portrait of the ecosystem. Scientists need that third dimension to calculate how much carbon is stored in a tree or in a forest. The GLOBE Observer: Trees tool allows citizen scientists to help investigate by using their smartphone to measure tree height. With the tool, observers record tree height by tilting their phone up and down to align the screen with the tree’s top branch and base, and pace off the distance to the tree; the app does the rest to calculate the tree’s height.
Tree height measurements could also help scientists working on NASA missions like the Ice, Cloud and land Elevation Satellite-2 (ICESat-2) which use lasers to measure the height of Earth’s surface below them as they orbit our planet. GLOBE measurements can be used for the validation of tree heights from ICESat-2. Once the GLOBE data starts coming in, the mission will analyze the information to see where a cluster of citizen scientist measurements overlap with ICESat-2’s measurements, and compare the two sets.