Some nice folks at the Washington Post had tipped us off that they were interested in doing a piece on fall foliage, and asked if we'd be able to lend a hand. Surprisingly, neither of us had ever specficially looked for fall colors from space before. We asked ourselves, could we?
The answer was a resounding yes - on nice cloud free shots, you can clearly see fall colors from Landsat and Sentinel-2 imagery. However, we wanted to go further. We wanted to create a broad view of fall colors across the country, a composite of fall foliage if you will, which the revisit times of Landsat and Sentinel-2 simply didn't allow. So, we turned to a coarser sensor for help: MODIS on the Aqua and Terra satellites.
Interestingly, the places with some of the best foliage in the country, like Pennsylvania, are also the cloudiest. After a lot of experimentation, we settled on weekly decadal rolling composites of MODIS imagery. Put another way, each composite included the same seven days over the past ten years, stepped forward by a single day. We found that this composite approach contained enough information to beat down clouds, while also being granular enough to tease out the entire spectrum of fall colors over time.
Check out the article for more details, with some bonus stunning foliage shots from higher resolution sensors.