MODIS/Terra Land Water Mask Derived from MODIS and SRTM L3 Global 250m SIN Grid V006

The MOD44W Version 6 data product was decommissioned on July 18, 2024. Users are encouraged to use the [MOD44W Version 6.1](https://doi.org/10.5067/MODIS/MOD44W.061) data product.

The Terra Moderate Resolution Imaging Spectroradiometer (MODIS) Land Water Mask (MOD44W) Version 6 data product provides a global map of surface water at 250 meter (m) spatial resolution. The data are available annually from 2000 to 2015. MOD44W Version 6 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. A primary improvement in Version 6 is the generation of time series data 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 Hierarchical Data Format 4 (HDF4) file are layers for land, water, no data, and an associated per pixel quality assurance (QA) layer that provides users with information on the determination of water.

Known Issues
* The mask area for pixels outside of the Sinusoidal Grid for tile h27v14 should be labeled as 250 (Outside of Projection) instead of 0 (Land) and the QA values should be 10 (Fill) instead of 3 (Lower confidence land) for years 2000 through 2015.
* Additional known issues are described in the User Guide and ATBD.
* For complete information about known issues please refer to the [MODIS/VIIRS Land Quality Assessment website](https://landweb.modaps.eosdis.nasa.gov/knownissue?sensor=MODIS&sat=Terra&as=6).