Underscoring how space technology can help us to better
understand and protect our home planet, NASA’s Jet Propulsion
Laboratory, Pasadena, Calif., has completed the first
comprehensive high-resolution topographic map of Central America,
a region where persistent cloud cover had made high-quality
satellite imagery difficult to obtain.
A mosaic image created from the map, which was collected
during the 2000 Shuttle Radar Topography Mission, is available on
the JPL Planetary Photojournal at:
http://photojournal.jpl.nasa.gov/catalog/PIA03364 .
The image depicts all of Central AmericaóBelize, Costa Rica,
El Salvador, Guatemala, Honduras, Nicaragua and Panamaóplus
southern Mexico and portions of Cuba and Jamaica. Home to 37
million people, Central America comprises just one-half percent
of Earth’s land mass, yet houses seven percent of Earth’s animal
species.
The dominant topographic feature of northern Central America
is the Sierra Madre Range, spreading east from Mexico between the
narrow Pacific coastal plain and the limestone lowland of the
Yucatan Peninsula. Parallel hill ranges sweep across Honduras
and extend south, past the Caribbean Mosquito Coast to lakes
Managua and Nicaragua. The Cordillera Central Mountains rise to
the south, gradually descending to Lake Gatun and the Isthmus of
Panama. A highly active volcanic belt runs along the Pacific
seaboard from Mexico to Costa Rica.
“Central America is a unique geographic region dominated by
rugged mountains, heavy vegetation and influenced by two major
oceans,” said Dr. Michael Kobrick, Shuttle Radar Topography
Mission project scientist at JPL. “Its proximity to Earth’s
equator and the Pacific and Caribbean results in frequent cloud
cover, which makes traditional satellite imagery difficult. The
Shuttle Radar Topography Mission’s synthetic aperture imaging
radar was able to penetrate that cloud cover, allowing the region
to be mapped more precisely than ever before. Residents of
Central America stand to benefit greatly from this more precise
digital elevation data, which can help them better prepare for
natural hazards such as landslides and floods, improve aviation
safety through a better understanding of mountainous terrain, and
increase the efficiency of critical infrastructure developments
such as roads, reservoirs, aqueducts and communications.”
Two visualization methods were combined to produce the
image: shading and color coding of topographic height. The shade
image was derived by computing topographic slope in the north-
south direction. Color-coding is directly related to topographic
height, with green at the lower elevations, rising through
yellow, red and magenta, to white at the highest elevations.
NASA is processing mission data for research purposes in
response to requests from NASA principal investigators and other
qualified scientists. NASA expects to release the Central America
data for broad public access in 2003.
The Shuttle Radar Topography Mission, flown from Feb. 11 to
Feb. 22, 2000, made 3-D measurements of the more than 80 percent
of Earth’s landmass between 60 degrees north and 56 degrees south
of the equator, areas home to nearly 95 percent of the world’s
population. The mission is a cooperative project of NASA, the
National Imagery and Mapping Agency of the U.S. Department of
Defense, and the German and Italian space agencies. It is
managed by JPL for NASA’s Earth Science Enterprise, Washington,
D.C.
For more information on the Shuttle Radar Topography
Mission, visit:
http://www.jpl.nasa.gov/srtm/ .
The California Institute of Technology in Pasadena manages
JPL for NASA.