The SASR
(Standard Atmosphere Surface Reflectance) product is a per-pixel, per-band
estimate of the surface spectral reflectance (in W m-2 µm-1)
as it would have been measured at ground level as if there were no atmospheric
contribution. It first calibrates imagery to the at-sensor (or
top-of-atmosphere or planetary) reflectances
and then, assuming a standard atmosphere, corrects it for the atmospheric
transmittance terms, atmospheric depth deviation from the sea level, sensor
off-nadir view angles, solar off-zenith angles, and the curvature of the earth.
The product is a raster image, linearly scaled between 0 (0% reflectance) to 10,000
(100% reflectance).
The SASR
calibration improves radiometric properties of the imagery and allows for
superior land cover and crop mapping, change analysis, as well as image
mosaicing and comparison.
Currently Supported Sensors: P6-AWiFS, P6-LISS III,
P6-LISS IV, Landsat 5 TM, Landsat 7 ETM+, Landsat 7 ETM+ SLC-off, IKONOS-2,
QuickBird-2, SPOT-2, SPOT-4, SPOT-5, DMC AISAT-1, DMC Beijing-1, DMC Deimos-1,
DMC NigeriaSAT-1, DMC NigeriaSAT-2, DMC UK-DMC-1, DMC UK-DMC-2. Additional
sensors may be available upon request.
- Standard Delivery Format: 16-bit integer uncompressed
GeoTIFF format stored in .zip archives
- Pixel Resolution: The same pixel
resolution as the original image
- Projection/ Reference System: The
same projection and reference system as the original image