USGS EROS Archive - Aerial Photography - Advanced Solid-state Array Spectroradiometer (ASAS)

Science Center Objects

The Advanced Solid-state Array Spectroradiometer (ASAS) data collection contains data collected by the ASAS sensor flown aboard NASA aircraft.

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Example of Advanced Solid-state Array Spectroradiometer (ASAS) Imagery

Example of Advanced Solid-state Array Spectroradiometer (ASAS) Imagery
(Public domain)

Advanced Solid-state Array Spectroradiometer (ASAS) data collected by National Aeronautical Space Agency (NASA) fundamental use is to characterize and understand the directional variability in solar energy scattered by various land surface cover types (e.g.,crops, forests, prairie grass, snow, or bare soil). The sensor's Bidirectional Reflectance Distribution Function determines the variation in the reflectance of a surface as a function of both the view zenith angle and solar illumination angle.

The ASAS sensor is a hyperspectral, multiangle, airborne remote sensing instrument maintained and operated by the Laboratory for Terrestrial Physics at NASA's Goddard Space Flight Center in Greenbelt, Maryland. The ASAS instrument is mounted on the underside of either NASA C-130 or NASA P-3 aircraft and is capable of off-nadir pointing from approximately 70 degrees forward to 55 degrees aft along the direction of flight. The aircraft was flown at an altitude of 5000 - 6000 meters (approximately 16,000 - 20,000 ft).  ASAS data are not geo-rectified or geo-located, nor are they corrected for atmospheric effects.

Data in the ASAS collection primarily cover areas over the continental United States, but some ASAS data are also available over areas in Canada and western Africa. The ASAS data were collected between 1988 and 1994. Some applications of ASAS data include validating forest canopy reflectance models, estimating biophysical parameters used in forest ecosystem models, deriving vegetation algorithms, and retrieving information on atmospheric properties.  See the NASA format document for more information on ASAS. 

Coverage Maps

Coverage Maps indicating the availability of ASAS Products are available for download.

Additional Information

Access Data

EarthExplorer can be used to search, preview, and download Advanced Solid-state Array Spectroradiometer (ASAS) data.  The collection is located under the Aerial Imagery category.

Digital Object Identifier (DOI)

Advanced Solid-state Array Spectroradiometer (ASAS) Digital Object Identifier (DOI) number: /10.5066/F7CF9NCQ