ASTER On-Demand L2 Polar Surface and Cloud ClassificationEntry ID: AST13POL
Abstract: This product is discontinued.
The ASTER On-Demand Level-2 Polar Surface and Cloud Classification product provides a classification map discriminating between different surface and cloud features over polar areas. The product aims to classify the cloud and snow-ice spectral signatures in both the visible and infrared wavelengths. The current algorithm works with data acquired during the daylight ... hours.
This product will assist those studying greenhouse forcings in the polar regions where cloud cover exerts its effects on sea ice conditions, the regional ice-albedo feedbacks, the polar heat balance, and surface melting. This product will provide data used in cross-validating the MODIS cloud optical thickness and effective particle sizes, both of which impact the Earth's radiative budget.
The ASTER On-Demand Level-2 Polar Surface and Cloud Classification product uses an hierarchical algorithm executed in four stages: In the first stage, the VNIR data are sub-sampled by half (15 m to 30 m) while the TIR data are sampled three times (90 m to 30 m). The SWIR data at 30 m are retained in their original resolution. The VNIR and SWIR digital numbers (DN) are normalized for solar irradiance, solar zenith angle, observation angle, and calibration coefficients. The TIR DNs are converted to temperature. In the second stage, the data are pre-classified to reduce the class ambiguity of a pixel's feature vector by using key features like coastline data, land-water mask etc. The third stage involves the use of a back-propagation neural network to aid in the resolution of feature vectors to one of nine possible classes. In the fourth stage, a spatial consistency test is performed on the classification mask and pixels deemed to be spatially inconsistent with their neighbors are re-classified. The final product is a coded pixel map containing the following thematic classes:
 ice cloud
 thin water cloud
 water cloud over water
 sea ice
 water cloud over land
 bare ground/tundra
V002 data set release date: 2001-10-26
V003 data set release date: 2002-05-03
The key determinants between these versions are the use of a newer algorithm with an improved set of radiometric calibration and geometric correction coefficients databases in version 003.
Data Set Characteristics:
Area: ~60 km x 60 km
Image Dimensions: 4200 rows x 4980 columns
File Size: ~42 MB
Projection: Universal Transverse Mercator (UTM)
Data Format: HDF-EOS
Vgroup Data Fields: 1
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Data Set Citation
Dataset Originator/Creator: Land Processes Distributed Active Archive Center (LP DAAC)
Dataset Title: ASTER On-Demand L2 Polar Surface and Cloud Classification
Dataset Release Date: 2001-10-26
Dataset Release Place: Sioux Falls, South Dakota, USA
Dataset Publisher: U.S. Geological SurveyOnline Resource: https://lpdaac.usgs.gov
Latitude Resolution: 30m
Longitude Resolution: 30m
Horizontal Resolution Range: 30 meters - < 100 meters
Quality Sensor anomalies may be present.
Access Constraints This product is discontinued.
Use Constraints None.
Data Set Progress
Distribution Media: HTTP
Role: TECHNICAL CONTACT
Phone: (Toll Free) (866) 573-3222
Phone: (605) 594-6116
Fax: (605) 594-6963
Email: LPDAAC at usgs.gov
LP DAAC User Services U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center 47914 252nd Street
City: Sioux Falls
Province or State: SD
Postal Code: 57198-0001
Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) publication references: [available online at http://asterweb.jpl.nasa.gov/asterbiblio20120719.pdf]
National Aeronautics and Space Administration, revised 2004, EOS Reference Handbook, a Guide to NASA's Earth Science Enterprise and the Earth Observing System: Greenbelt, Maryland, Goddard Space Flight Center, 261 p. [available online in pdf format at http://eospso.gsfc.nasa.gov/ftp_docs/data_products_1.pdf].
Extended Metadata Properties
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Creation and Review Dates
DIF Creation Date: 2002-08-05
Last DIF Revision Date: 2013-01-31