EDG Data Set Name
ASTER On-Demand L2 Decorrelation Stretch TIR
Granule Shortname
AST_06TD
Data Set Characteristics
Area: ~60 km x 60 km
Image Dimensions: 700 rows x 830 columns
File Size: ~3 Megabytes
Spatial Resolution: TIR: 90 m
Projection: Universal Transverse Mercator (UTM)
Data Format:
HDF-EOS
GeoTIFF
Vgroup Data Fields: 3
Product Description The ASTER On-Demand L2 Decorrelation Stretch (TIR) is an on-demand product with user-specified processing options. Users need to pick three from the available five TIR spectral bands as input. This product is a color-enhanced image of the TIR radiance data, produced from ASTER Level-1B data set. Decorrelation stretch is a process used to enhance the color differences in an image by removing the inter-band correlation in the radiance values of the input TIR pixels. Such an image provides a general overview that emphasizes emissivity and reflectance variations, and restrains variations owing to topography and temperature. The general purpose of a decorrelation stretched image is to serve as a data visualization tool while reviewing and selecting ASTER image data for further analysis and research. It attempts to address three broad requirements of such a visualization tool:
How well does the image spectrally discriminate among different feature types?
How consistent are the color, brightness, and spectral signatures across time and space?
How consistent is the information in the image compared to other satellite images, maps, and aerial photographs?
The decorrelation stretch product algorithm calculates the principal components of a three-band TIR image. Each component is rescaled or contrast-stretched by normalizing the variances of the vectors, and rotated back into the RGB color space.
Ordering ASTER On-Demand L2 Decorrelation Stretch TIR Product
The ASTER Decorrelation Stretch TIR product can be ordered through the EOS Data Gateway. The process and procedures for ordering this product are described in the following tutorial: http://lpdaac.usgs.gov/tutorial/. As part of that process, it is necessary to first select an ASTER Level 1A granule from the EOS Data Gateway.
LP DAAC User Services
U.S. Geological Survey (USGS)
Earth Resources Observation and Science Center (EROS)
47914 252nd Street
Sioux Falls, SD 57198-0001