Thermal imaging from
satellites can be used for monitoring drought and water consumption,
administering irrigation projects, and predicting water demand. Image
courtesy of Martha Anderson, ARS. |
|
Taking Earth's Temperature via Satellite
By Don
Comis August 12, 2008
Imagine adding a thermometer to GoogleTM Earth. That's the
vision of Agricultural Research
Service (ARS) scientists
Martha
Anderson and
Bill
Kustas, who see the need for high-resolution thermal infrared imaging
tools--such as those aboard the aging Landsat satellites--as vital to monitoring
earth's health.
These thermal data are especially important given the combination of
global warming and the growing population's increasing demand for water.
Anderson is a physical scientist and Kustas is a hydrologist at the
ARS Hydrology
and Remote Sensing Laboratory in Beltsville, Md. Based on remote sensing
experiments over the past two decades, Anderson and Kustas see the potential to
combine results from a suite of satellites for regional monitoring of
evapotranspiration and drought on a daily basis.
As with GoogleTM Earth, users could zoom in from the
continental scale to a single field or irrigation operation.
Thermal remote sensing of the earth's land surface and plant canopies
from satellites is a valuable way to diagnose water stress and drought
conditions. Also, thermal imaging can be used in lieu of precipitation data,
providing much-needed information on soil moisture status in data-poor parts of
the world.
The ability to map evapotranspiration and soil moisture via satellite
has broad applications in monitoring drought and water consumption,
administering irrigation projects, predicting water demand, and providing
information for hydrological and weather forecast computer models.
Landsat 5 is more than 24 years old; Landsat 7 is 9 years old, but
already has operational problems. When the Landsat satellites fail, which could
happen at any time, there will be a gap in high-resolution thermal measurements
until the National Aeronautics and Space
Administration launches its HypspIRI satellite, possibly sometime between
2013 and 2020.
An article on this research recently appeared in
Eos, a weekly newspaper
published by the American Geophysical Union.
ARS is a scientific research agency of the
U.S. Department of
Agriculture.