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Cropland Datalayer Layer (CDL) are satellite images depicting
agricultural land cover. The images are a useful tool for
monitoring crop rotation patterns, land use changes, water
resources and carbon emissions.
These crop-specific, digital data layers are suitable for
use in geographic information systems (GIS) applications.
They can be used by agribusinesses, farmers, government agencies,
researchers and academic institutions to study pesticide risk,
epidemiology, transportation, fertilizer usage, carbon dioxide
flux and other topics.
NASS produced the CDLs using satellite images observed at
56-meter (0.775 acres per pixel) resolution and collected
from the Resourcesat-1 Advanced Wide Field Sensor (AWiFS),
Landsat Thematic Mapper and Moderate Resolution Imaging Spectroradiometer
(MODIS). The collection of images was then categorized using
on-the-ground farm information including field location, crop
type, land cover, elevation, tree canopy and urban infrastructure.
The most current CDL data is available free for download along with extensive metadata, FAQs, and other detailed technical information at http://www.nass.usda.gov/research/Cropland/SARS1a.htm.