Mapping tree cover is vital for monitoring deforestation, restoration and trends in global land cover change. Remote sensing makes it possible to observe forests on a global scale by analyzing imagery from satellites to detect where trees are and aren’t over time. It’s not just dense forests that are important; open canopy forests — which are common in drylands and in non-forested regions like in cities and on farms — are also important to map and monitor. However, doing so has proven challenging: Patches of trees may cover a smaller area than individual satellite pixels.