Vector representation of ice sheet velocity in meters per year for 2021. Calculated by QGreenland Team. === Original Data Source === MEaSUREs Greenland Annual Ice Sheet Velocity Mosaics from SAR and Landsat, Version 4 This data set, part of the NASA Making Earth System Data Records for Use in Research Environments (MEaSUREs) program, contains annual ice velocity mosaics for the Greenland Ice Sheet derived from Synthetic Aperture Radar (SAR) data obtained by the German Space Agency's TerraSAR-X/TanDEM-X (TSX/TDX) and the European Space Agency's Copernicus Sentinel-1A and -1B satellites, and from the US Geological Survey's Landsat 8 optical imagery for years 2015 to 2021. See Greenland Ice Mapping Project (GrIMP) website for related data: http://nsidc.org/data/measures/gimp. Citation: Joughin, I. (2022). MEaSUREs Greenland Annual Ice Sheet Velocity Mosaics from SAR and Landsat, Version 4 [Data Set]. Boulder, Colorado USA. NASA National Snow and Ice Data Center Distributed Active Archive Center. https://doi.org/10.5067/RS8GFZ848ZU9. [Accessed on: 2023-08-24] Citation URL: https://doi.org/10.5067/RS8GFZ848ZU9