Web Site Helps Teachers Use Landsat Images in the Classroom

Contact: Carolyn Merry, (614) 292-6889; Merry.1@osu.edu
 
Written by Pam Frost, (614) 292-9475; Frost.18@osu.edu
 

COLUMBUS, Ohio — An Ohio State University engineer has designed a Web- based teaching aid to help deliver satellite images of Earth to classrooms around the country.
 
The teacher’s kit, called "A Global View of the Earth," helps teachers create lesson plans and activities for 5th to 8th grade students using images taken by NASA’s Landsat-7 satellite.
 
Carolyn Merry, associate professor of civil and environmental engineering and geodetic science, described the teacher’s kit May 30 at the American Geophysical Union Spring Meeting in Washington D.C.
 
"It’s imperative that we share these images with the public, particularly with students in grade schools and high schools, so they can realize satellite images are a resource for learning just like a book or encyclopedia," Merry said.
 
Teachers can use Landsat images for lessons in any number of environmental subjects, from agriculture and geology to urban planning, Merry said. Space science and cartography are two of many other possibilities.
 
Teachers can learn more about "A Global View of the Earth" at     http://ltpwww.gsfc.NASA.gov/Landsat7/teacherkit/index.html .
The Biospheric Sciences Branch of NASA Goddard Space Flight Center funds the project.
 
Merry began this project during a sabbatical in 1998, when she was a visiting scientist at NASA Goddard Space Flight Center in Greenbelt, MD. Karen Chu, an undergraduate education major from the University of Maryland, helped Merry with the project.
 
The teacher’s kit breaks the study of Landsat images into several individual lessons. First, students learn about Landsat itself and construct a paper model of the satellite.
 
Next students identify "mystery images" — full-color, visible-light images of man-made objects like airports, bridges, and golf-courses as seen by Landsat from more than 400 miles above. Then they see images taken at other wavelengths of electromagnetic radiation.
 
Since Landsat records images of the earth in seven different wavelengths — including near-infrared and thermal radiation and different colors of visible light — different images emphasize different aspects of a region.
 
Forests, Merry explained, appear dark in visible blue wavelengths of light, but bright in the near infrared. Pavement reflects brightly across all wavelengths.
 
Merry routinely combines satellite images taken at different wavelengths for her research of water quality. Water containing many small particles appears bright in blue light, she explained, but dark in infrared. "We integrate different sets of data together, and that gives us a better handle on what’s going on in the water," she said.
 
Lastly, the teacher’s kit helps students tackle the more complex problem of how Landsat orbits the earth. The students calculate the satellite’s orbital path, for instance, and its height above the earth.
 
The teacher’s kit takes advantage of the fact that copies of Landsat images now cost a fraction of what they did a few years ago. Poster-sized images showing regions of the United States 115 miles wide — the distance from Washington, D.C. to Ocean City, MD — now cost less than $500, down from $4,400. The new price reflects NASA’s change of commercial companies to market the images to the public, Merry said.
 
Schools can use the teacher’s kit even if they can’t afford the $600 posters. Some images are available on-line, as are graphics of Landsat-7. All written materials, including descriptions of the satellite and instructions on interpreting the images, are free.
 
Merry is involved in another NASA outreach program for Landsat data — the OhioView Consortium. Organized by eight Ohio colleges and universities, the consortium will give Ohio students a unique opportunity to learn about geographic features in their home state, Merry said.
 
With the help of NASA Glenn Research Center and the online library system OhioLink, as well as Ohio State and the seven other Ohio colleges and universities, the U.S. Geological Survey (USGS) is cataloging images taken by Landsat-7 each time it passes over Ohio — once every 16 days. Students will be able to see how the Ohio landscape changes over the course of a year, Merry said.
 
And, because Landsat launched its first satellite in 1972, students can gauge the expansion of cities and suburbs in Ohio since then. The nearly 30-year-old images are still available, Merry pointed out, and USGS sells them at a reduced price.
 
OhioView Consortium images will be free to all educational institutions. Merry and other researchers from Ohio State are working to break the high-resolution images into manageable chunks so schools can easily download them from the Web. If successful, USGS plans to expand its pilot project in Ohio to other states in the future.
 
The OhioView Consortium is also funded by NASA.
 
Merry continues to revise and update the teacher’s kit. She gives workshops on interpreting satellite data to interested schools around Ohio, and to teachers and students who visit Ohio State.