GeoFile 2006-8:
Examining ASTER Imagery with the MapPlace Image Analysis Toolbox
A Tutorial Manual
W.E. Kilby and C.E. Kilby
Cal Data Ltd.
Geoscience BC Report 2006-3
Contribution #GBC 015
Data Release
View GeoFile 2006-8 (PDF,
5520 KB)
View Video Tutorials
Remote sensing images have been continually added to the
MapPlace since 2003. The
Image Analysis Toolbox (IAT)
was created to utilize this data. Making use of such image data is new for
many clients of the website. This manual is provided as an introduction to
ASTER imagery and to assist users in navigating the toolbox. Portions of
this manual are derived from three B.C. Geological Survey papers in
Fieldwork: Kilby et al. (2004), Kilby (2005) and Kilby and Kilby (2006), and
many other sources noted in the text or under References at the end of the
manual.
Advanced Spaceborne Thermal Emission and Reflection
Radiometer (ASTER) is an imaging instrument flying on the Terra satellite,
launched in late 1999. The instrument has 3 subsystems that capture
readings from different portions of the electromagnetic spectrum at
different resolutions. The three subsystems are referred to as VNIR (Visible
and Near Infrared), SWIR (Shortwave Infrared) and TIR (Thermal Infrared).
Reflectance values in the SWIR range are particularly useful in
differentiating rock and soil mineralogy related to alteration zones.
An ASTER image contains 14 bands of information, 4 bands in
the VNIR with 15 metre resolution, 6 bands in the SWIR with 30 metre
resolution and 5 bands in the TIR with 90 metre resolution. Two of the VNIR
bands sample the same wavelength range but one is back-looking providing the
ability to generate a stereo view of the scene. A single ASTER scene covers
an area of about 60 by 60 kilometres. The ASTER web site
http://asterweb.jpl.nasa.gov is
an excellent source of information on the instrument, its mission, available
imagery, usage examples and analysis tools.
The “Image Analysis Toolbox” project developed and
implemented an image analysis capability for the MapPlace and was delivered
by Cal Data Ltd. The Toolbox is a framework in which a variety of multi and
hyperspectral imagery can be added and processed online by end users. The
results of the analysis are georeferenced and can be completely integrated
with the information already contained in the MapPlace. The suite of
analysis tools in the IAT was added to the
Exploration
Assistant page of the MapPlace. The appearance and operation of the IAT
was designed to maintain the general look and feel of the Exploration
Assistant. The purpose of the Toolbox is to provide the ability for MapPlace
users to experiment with a variety of imagery and analysis procedures in
their search for exploration targets.
