Ice sheet velocity x component (vx) in meters per year for 2021.
Annual mosaics are produced from data with resolutions varying from a few
hundred meters to 1.5km. The 2021 annual mosaic includes data collected between
2020-12-01 and 2021-11-30.

Note that these data have been rounded to the nearest centimeter for QGreenland
to save disk space. Please see the original data source for the un-modified and
additional data:

* x and y component velocity error estimates (ex, ey).
* A temporal offset parameter (dT) that reports the difference in days between
  the date of each velocity estimate and the midpoint date of the corresponding
  measurement period.
* Shapefile that indicates the source of the image pairs (SAR or Landsat 8) used
  to produce the mosaic.

=== 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