PC Media 4/PC MEDIA CD04.iso/nasa/sc-raco.txt

Text File | 1995-02-23 | 4KB | 69 lines

PUBLIC INFORMATION OFFICE
JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIFORNIA 91109.  TELEPHONE [phone]

PHOTO CAPTION                                             P-43882
                                                   April 10, 1994

This image is a false-color composite of Raco, Michigan, centered
at 46.39 degrees north latitude, 84.88 degrees west longitude.
This image was acquired by the Spaceborne Imaging Radar-C and X-
Band Synthetic Aperture Radar (SIR-C/X-SAR) aboard the space
shuttle Endeavour on its sixth orbit and during the first full-
capability test of the instrument on April 9, 1994.  This image
was produced using both L-band and C-band data.  The area shown
is approximately 20 kilometers by 50 kilometers (12 by 30 miles).
Raco is located at the eastern end of Michigan's upper peninsula,
west of Sault Ste. Marie and south of Whitefish Bay on Lake
Superior.  The site is located at the boundary between the boreal
forests and the northern temperate forests, a transitional zone
that is expected to be ecologically sensitive to anticipated
global changes resulting from climatic warming.  On any given
day, there is a 60 percent chance that this area will be obscured
to some extent by cloud clover which makes it difficult to image
using optical sensors.  In this color representation (red=LHH,
green=LHV, blue=CHH), darker areas in the image are smooth
surfaces such as frozen lakes and other non-forested areas.  The
colors are related to the types of trees and the brightness is
related to the amount of plant material covering the surface,
called forest biomass.  The black area in the upper right corner
is the ice-covered Lake Superior.  The blue mosaic areas in the
lower part of the image are bare agricultural fields with hay
stubble.  The large blue area to the center left of the image
corresponds to a large frozen swamp with no trees and lots of
grass trufts.  The light greenish-yellow areas are red pine trees
approximately 30 meters (100 feet) in height.  The brownish
yellow areas are jack pine trees of various ages.  The dark
patches are areas of recent clear cuts in the managed Hiawatha
National Forest.  The shore line of Lake Superior in the light
greenish blue is a mixture of aspen and birch trees.  South of
that, surrounding McNearny and Johnson lakes is a dark purple
area containing north hardwoods.  Accurate information about
land-cover is important to area resource managers and for use in
regional- to global-scale scientific models used understand
global change.

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SIR-C/X-SAR radars illuminate Earth with microwaves allowing
detailed observations at any time, regardless of weather or
sunlight conditions.  SIR-C/X-SAR uses three microwave
wavelengths:  L-band (24 cm), C-band (6 cm), and X-band (3 cm).
The multi-frequency data will be used by the international
scientific community to better understand the global environment
and how it is changing.  The SIR-C/X-SAR data, in conjunction
with aircraft and ground studies, will give scientists clearer
insights into those environmental changes which are caused by
nature and those changes which are induced by human activity.
SIR-C was developed by NASA's Jet Propulsion Laboratory.  X-SAR
was developed by the Dornier and Alenia Spazio companies for the
German space agency, Deutsche Agentur fuer
Raumfahrtangelegenheiten (DARA), and the Italian space agency,
Agenzia Spaziale Italiana (ASI) with the Deutsche
Forschungsanstalt fuer Luft und Raumfahrt e.v. (DLR), the major
partner in science, operations and data processing of X-SAR.

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