GLOBE Observer

I found a pretty cool app from NASA called Globe Observer which, among other things, lets you measure the height of a tree. I’d often wondered how tall a few of our bigger trees are and today I used the app to measure one of our biggest Douglas firs. (We’re mostly redwoods but we have about half a dozen big Doug firs that range from a few feet in diameter to over 5 feet.)

The big Doug fir tree that I measured today has a diameter of just over 5 feet at chest height (which I already knew) and today I learned it’s about 230 feet tall. Wild! That’s taller than a 20 story building.

I can’t see the base and top of our big redwood from any easy vantage point, which the app requires, so I can’t easily measure it but it’s a 7 foot DBH tree that’s sits lower and sticks up above this Doug fir so I’m guessing it over 250 feet tall.

These are some pretty big trees — nothing like the old growth redwood giants in the park next door, but substantial nonetheless.

If you’re interested in measuring trees around you, check out the app in the Android and iOS app stores: https://observer.globe.gov/about/get-the-app

Note: I didn’t explain the app. It’s an augmented reality app that uses your camera to overlay a marker you line up with the bottom of the tree and the top of the tree. Presumably the app uses the gyroscope in the phone to calculate the angle you tilted the phone when marking the bottom and top of the tree. Then the app asks you to pace off the distance to the foot of the tree. From your height it estimates your stride length and the distance to the tree. With the distance to the foot of the tree and the angle it can calculate the height of the tree.