True-color corrected reflectance images of the Ridge-and-Valley Appalachians in Maryland, Virginia, and West Virginia. This comparison image compares imagery from August 26, 2021, on the left ("A" side) with imagery from November 9, 2021, on the right ("B" side). Move the center swipe line back and forth to see the difference between the vegetation in the summer and autumn. The summer vegetation is mostly green while the right side shows the ridges and mountains are covered in senescing trees, with leaves changing to red and brown.
This image was acquired by the Multi-Spectral Instrument (MSI), aboard the ESA (European Space Agency) Sentinel-2A and -2B satellites. It is available in NASA's Worldview as a part of the Harmonized Landsat Sentinel-2 (HLS) project that provides 30 meter resolution true-color surface reflectance imagery from the Operational Land Imager (OLI) instrument aboard the joint NASA/USGS Landsat 8 and the Multi-Spectral Instrument (MSI) aboard the ESA Sentinel-2A and -2B satellites. The data from the two instruments aboard the three satellites are processed through a set of algorithms to make the imagery consistent and comparable across the instruments. This includes atmospheric correction, cloud and cloud-shadow masking, spatial co-registration, and common gridding, illumination, and view angle normalization, and spectral bandpass adjustment.