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.
|File Size||~500 KB|
|Temporal Extent||2000-01-01 to 2015-12-31|
|Geographic Dimensions||1200 km x 1200 km|
|Number of Science Dataset (SDS) Layers||2|
|Pixel Size||250 m|
|SDS Name||Description||Units||Data Type||Fill Value||No Data Value||Valid Range||Scale Factor|
|Water_mask||Land/Water Mask||N/A||8-bit unsigned integer||250||253||0 to 1||N/A||Water_mask_QA||Quality Assurance (QA)||N/A||8-bit unsigned integer||10||253||1 to 8||N/A|
|250||Outside of Projection|
|1||High confidence observation|
|2||Lower confidence water, but MOD44W V5 indicated water|
|3||Lower confidence land|
|5||Ocean mask, but no water observations recorded|
|6||Burned area (MCD64A1)|
|7||Urban or impervious surface|
|8||No water detected, but MOD44W V5 shows inland water|
|10||Fill (outside of projected area)|
Quality information is provided in the Water Mask QA layer. Additional product quality information is provided on page 5 of the User Guide and Algorithm Theoretical Basis Document (ATBD).
Known issues are described in the User Guide and ATBD.