October 02, 2008 –
Researchers take to the field at the Santa Margarita Ecological Reserve.
When the Hyperspectral Airborne Tactical Instrumenttook a test flight recently over the Santa Margarita Ecological Reserve near San Diego, researchers from several organizations, including the CALIT2-affiliated Center for Hydrometeorology and Remote Sensing, were on the ground, doing their part to help test and calibrate the airplane-mounted high-resolution imaging device.
HATI uses technology first developed for NASA’s Earth Observing satellite sensors. It allows scientists to obtain incredibly detailed views of trees, vegetation, soil, moisture and other ground data undetectable to the human eye.
All objects possess a unique spectral identification – similar to a fingerprint – created as they reflect solar radiation at various wavelengths. Only a small portion of the wavelength spectrum is visible to the human eye, but hyperspectral imaging can measure reflected light at hundreds of wavelengths beyond the eye’s reach.
In fact, a hyperspectral sensor can measure 20 times as much information as a standard sensor – enough to differentiate between healthy and dry vegetation or detect the amount of moisture in soil.
“There are zillions of pieces of information in these bands that we cannot see,” says CHRS’s Soroosh Sorooshian.
Because Northrop Grumman seeks to make existing sensor technology smaller, more economical and customizable, the test project requires scientists to determine whether they can get the information they need from the equipment.
“We’re looking at how we can build very low-cost, rapid turnaround spacecraft that will actually serve weather and climate needs,” said Brian Baldauf, who works in environmental systems at Northrop Grumman’s Space Technology division. “We want to integrate ground-sensing capabilities with space sensors and that’s why it’s exciting to work with UCI.”
Before the flight, CALIT2 researchers joined their colleagues to identify specific areas from which they wanted information. While the test flight was gathering massive amounts of data from the reserve, researchers on the ground were taking their own spectral measurements of the same areas to see if the datasets would match. “We dug trenches to get an idea about soil moisture, we looked at areas with burn and with no burn, and we looked for areas of thick vegetation,” says Bisher Imam. The researchers are now analyzing the data sets to see if they contain the right information.
The project is ongoing and no conclusions have been reached, but the ultimate goal for researchers is to identify trends. The more scientists know about an area, the better their meteorological predictions. “In each area that the same amount of rain falls, different amounts are going into the water supply, depending on all the conditions in that area,” Imam explains. “The more precise our information is about what’s on the ground, the more accurate our forecasts can be.”
Other partners in the project include NASA’s Ames Research Center, Cal State San Diego and the Scripps Institute at UCSD.
— Anna Lynn Sptizer
