MODIS/Terra Land Water Mask Derived from MODIS and SRTM L3 Global 250m SIN Grid V061

Description

The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) Land Water Mask (MOD44W) Version 6.1 data product provides a global map of surface water at 250 meter (m) spatial resolution. The data are available annually from 2000 to present. MOD44W Version 6.1 is derived using a decision tree classifier trained with MODIS data and validated with the Version 5 MOD44W data product. A series of masks are applied to address known issues caused by terrain shadow, burn scars, cloudiness, or ice cover in oceans. Version 6.1 is the generation of a time series rather than a simple static representation of water, given that water bodies fluctuate in size and location over time due to both natural and anthropogenic causes. Provided in each MOD44W Version 6.1 Hierarchical Data Format 4 (HDF4) file are layers for land water mask and water body classification. A quality assurance (QA) layer provides users with information on the determination of water. The new seven class water classification layer provides values for shallow ocean, land, shoreline, inland water, ephemeral water, deep inland water, moderate ocean, deep ocean, and a classification deemed to fall outside of the projection. Improvements/Changes from Previous Versions * The Version 6.1 Level-1B (L1B) products have been improved by undergoing various calibration changes that include: changes to the response-versus-scan angle (RVS) approach that affects reflectance bands for Aqua and Terra MODIS, corrections to adjust for the optical crosstalk in Terra MODIS infrared (IR) bands, and corrections to the Terra MODIS forward look-up table (LUT) update for the period 2012 - 2017. * A polarization correction has been applied to the L1B Reflective Solar Bands (RSB). * Additional data files will be produced annually and are scheduled for distribution in the first quarter of the calendar year. * Seven-class water body classification layer produced at 250 meter resolution is provided in tiled format. * For Collection 6.1 and beyond, Antarctica data are now being produced.

Resources

Name Format Description Link
33 The Algorithm Theoretical Basis Document (ATBD) describes the physical and mathematical algorithms for the product. https://lpdaac.usgs.gov/documents/1915/MOD44W_User_Guide_ATBD_V61.pdf
21 The LP DAAC product page provides information on Science Data Set layers and links for user guides, ATBDs, data access, tools, customer support, etc. https://doi.org/10.5067/MODIS/MOD44W.061
21 Classes 4 and 5 of the Water Body Classification Values are incorrectly listed in the data files. Users are requested to follow the legend provided in the User Guide or the Data Set Landing Page. https://landweb.modaps.eosdis.nasa.gov/displayissue?id=568
20 LP DAAC Data Pool provides direct access to available products via HTTPS. https://e4ftl01.cr.usgs.gov/MOLT/MOD44W.061/
20 Earthdata Search allows users to search, discover, visualize, refine, and access NASA Earth Observation data. https://search.earthdata.nasa.gov/search?q=C2565805847-LPCLOUD
21 The LP DAAC website provides detailed information on discovery, distribution, access, and support of land data products. https://lpdaac.usgs.gov/
21 Validation at stage 3 has been achieved for the MODIS Vegetation Continuous Fields data product. https://modis-land.gsfc.nasa.gov/MODLAND_val.html
21 Search results for publications that cite this dataset by its DOI. https://scholar.google.com/scholar?q=10.5067%2FMODIS%2FMOD44W.061
21 Further details regarding MODIS land product validation for the MOD44 data are available from the MODIS Land Team Validation site. https://modis-land.gsfc.nasa.gov/ValStatus.php?ProductID=MOD44

Tags

  • land-surface
  • national-geospatial-data-asset
  • surface-water
  • terrestrial-hydrosphere
  • ngda
  • surface-radiative-properties
  • earth-science

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