As Bruno described last month, we leverage the Landsat Ecosystem Disturbance Adaptive Processing System, or LEDAPS, software routines to process Landsat Level 1 images to surface reflectance. This conversion is one of the most important steps in our larger imagery processing pipeline.Surface Reflectance
Surface reflectance measures the ratio of solar radiation reflected from, rather than absorbed by, the Earth’s surface. To achieve the most accurate reflectance measurement, the effects of the atmosphere need to be taken into account.Landsat surface reflectance products contain the measurements the sensor would capture under ideal conditions — held right above the Earth’s surface without any effects caused by the atmosphere.
Surface reflectance products are ideally suited for change detection and monitoring applications, as removing the atmospheric effects makes it easier to compare images over time. Many higher-level surface geospatial analyses — including vegetation indexes, albedo, Leaf Area Index (LAI), burned area, land cover, and land cover change — rely on surface reflectance products.
The difference is striking — as you can see in the before and after over Hong Kong below.