Proportional estimates of cover are developed from global training data derived using high-resolution imagery. The training data and phenological metrics are used with a regression tree to derive percent cover globally. The model is then used to estimate areal proportions of the following:
The current V004 collection of the yearly MODIS Vegetation Continuous Fields (VCF) product contains only percent tree cover, with the other layers to follow in later releases.
The data layers in the VCF product (MOD44B) are generated on an annual basis from monthly composites of MODIS 500-meter Surface Reflectance data. Compositing is based on the second darkest albedo to remove clouds and cloud shadow. Bands 1–7 are used to derive metrics for the calculation of percent tree cover. Any areas of confusion are alleviated using an additional metric derived from the MODIS Surface Temperature product composited to the same 32-day time step.
Inter-annual comparison of the percent tree cover product should be done with extreme caution as there are many reasons for fluctuations in the percentage from year to year. Until on-going development of a multi-year change product derived from VCF is complete, users interested in change are encouraged to look at the MODIS Vegetative Cover Conversion product.
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Area | ~10 x 10 lat/long |
File Size | ~1.3 MB |
Projection | Sinusoidal |
Data Format | HDF-EOS |
Dimensions | 2400 x 2400 rows/columns |
Resolution | 500 meters |
Science Data Sets (SDS HDF Layers) | 1 |
U.S. Geological Survey (USGS)
Center for Earth Resources Observation and Science (EROS)
47914 252nd Street
Sioux Falls, SD 57198-0001
Phone Number: | 605-594-6116 |
Toll Free: | 866-573-3222 |
866-LPE-DAAC | |
Fax: | 605-594-6963 |
Email: | lpdaac@eos.nasa.gov |
Web: | http://lpdaac.usgs.gov |