Monitoring glaciers and ice sheets is complicated work. They move and change shape. They melt.
A scientist at Rochester Institute of Technology is giving NASA better tools for assessing changes in the fragile polar region. John Kerekes won a three-year, $561,130 grant from NASA to help the space agency's scientists better interpret remotely sensed data collected with laser light.
The technology -- known as lidar or "light detection and ranging" -- measures altitude by shooting pulses of laser light, or photons, at a target. The light pulses reach the surface and bounce back to the sensor. The detector measures the distance traveled and forms an image of the shape pulse by pulse. The processed data creates three-dimensional renderings or digital elevation maps that scientists can use to measure changes in the polar ice. Future NASA missions, such as the upcoming Ice, Cloud and land Elevation Satellite-2, or ICESat-2, will use lidar devices. Slated for launch in 2016, ICESat-2 will measure ice-surface topography and assess changes to Greenland and Antarctic ice sheets and sea ice.
"The ICESat-2 science team wants to be able to measure annual changes in ice-sheet thickness to within a few millimeters, averaged over the entire ice sheet," says Kerekes, an associate professor in the Chester F. Carlson Center for Imaging Science at RIT.
"Take a flat mirror -- a pulse of light comes down, bounces off the mirror and you know exactly how long it took," he explains. "But real ice sheets and glaciers have narrow crevasses that may be only a few meters wide and tens of meters deep. And the laser pulse is going to interact with that complex surface in a way that will be very different than if it were just a flat surface."
Kerekes' team will give lidar a trial run in a simulated arctic environment well before NASA launches the technology on its future mission. They will use the Digital Imaging and Remote Sensing Image Generation t
|Contact: Susan Gawlowicz|
Rochester Institute of Technology