Surface reflectance

The fraction of sunlight a surface reflects in each band, after removing the atmosphere’s distortion. The standard “analysis-ready” optical measurement.

Why it matters

Reflectance is what vegetation indices, land-cover classification, and most optical science are built on — atmospheric correction makes scenes from different days comparable.

In plain terms

The surface’s true color and brightness, with the haze of the atmosphere stripped away — so today’s image matches last month’s.