| FOR IMMEDIATE RELEASE | Contact Sandra Cleva: (703) 379-2480 |
| October 1, 1997 | E-mail: geotimes@agiweb.org |
ALEXANDRIA, VA. -- "The satellites are coming," warns longtime remote-sensing
expert William E. Stoney in the October issue of Geotimes. And they're bringing
with them dramatic improvements in our ability to study Earth from space.
In his article "Data Deluge," Stoney describes in detail the remote-sensing revolution
that's now under way. His review of our current satellite resources and those in the works
fittingly marks the 25th anniversary of the first Landsat launch.
In 1972, Landsat 1 began civilian land-sensing programs for the United States; earth-
observation systems from 10 other countries are also operating today. "NASA should be
proud," Stoney writes. "Imitation is the sincerest form of flattery." But in addition to the
Landsat-like satellites, there are numerous other systems in orbit, and many more to come.
Hyperspectral and radar satellites will provide us with capabilities barely dreamed of 25 years
ago.
The satellite data will have multiple uses in fields ranging from mapping and land
management to mineral exploration and monitoring global change. As Stoney explains, "Earth-
observation satellites will be providing more and increasingly better data to help us understand
our planet's surface and manage its problems."
Improving our understanding of Earth is also the theme of J.H. Fang's article, "Fuzzy
Logic and Geology." Fang explains the strange but useful world of fuzzy logic and fuzzy
reasoning, and argues that these analytical tools can help geologists make sense of the
"complex" and "ill-defined systems" they study.
Fang looks at conventional set theory and contrasts it with fuzzy concepts, using simple
examples to describe membership in sets, and grades or degrees of membership. He explains
the difference between probability and possibility, and then moves on to define fuzzy logic and
fuzzy reasoning.
"Just as conventional logic is derived from binary set theory, fuzzy logic is rooted in
fuzzy set theory," Fang writes. "Although it is over 2,000 years since Aristotle invented logic,
the basic assumption upon which two-valued logic is based -- that every proposition is either
true or false -- has not changed. But," he continues, "things are not always black or white...
[and] two-valued logic has been extended to many-valued logic, which forms the kernel of
fuzzy logic." It is precisely this ability to deal with matters that are not simply "black or
white" that makes fuzzy logic a useful approach to geoscience.
Also in Geotimes, Cathryn A. Manduca contributes the story of a highly
successful model for student research, the Keck Geology Consortium Undergraduate Research
Program. "Learning Science Through Research" captures the enthusiasm of the student
participants for a program that allows them to explore exciting problems in geology and make
real contributions to the science.
Last summer, nearly 80 students took part in the Keck Program, working on eight
projects around the country. One group, based at Washington and Lee University in
Lexington, Va., investigated the planets; another collected field data to test a thory of
landscape evolution for the Basin and Range Province.
All of the students will present the results of their research at the Keck Research
Symposium next spring. All will, as Manduca writes, "Know what it means to do science."