By Sean Leviashvili
Last month, Purnima Ratilal, assistant professor at Northeastern’s electrical and computer engineering department, was one of 67 researchers nationwide to receive the Presidential Early Career Award for Scientists and Engineers (PECASE) for 2007.
Ratilal was selected by the Office of Naval Research, under the Department of Defense, for her investigative research on acoustics and remote sensing, which encompasses sonar, a method for detecting and locating objects submerged in water by echolocation. The award ceremony was held at the US President’s Office of Science in the White House and took place Dec. 19.
Research has been a cornerstone at Northeastern, but not without funding, Ratitlal said.
“Northeastern is providing opportunities for research, but the one limitation is the funding available,” she said. “My colleagues and I [do what we can] but more can be done, especially for undergraduates.”
As a recipient, Ratilal will receive $200,000 a year for five years to fund her research. The total amount of $1 million will be used to hire graduate students and provide for future experiments, new equipment and conference travel. The sum awarded to recipients including Ratilal is funded by organizations like the Environmental Protection Agency and National Institute of Research.
“Most of these agencies have career awards that young faculty members can apply for,” Ratilal said. “In 2007, I got the Office of Naval Research Young Investigator Award, and from that point, I was able to be considered for the PECASE.”
In 2006, Ratilal coordinated a three-week long experiment that focused primarily on detecting and studying schools of Atlantic Herring. It was conducted in the Gulf of Maine and called the “Ocean Acoustic Wave Remote Sensing”, in which the system of Ocean Acoustics Waveguide Remote Sensing was tested. The system can image an area roughly 100 km, or approximately 62 miles in diameter within a minute, she said.
“We were able to show how fish can be classified over vast areas by mapping their acoustic scattering response and resonance frequencies,” Ratilal said.
Currently, Ratilal runs the Laboratory for Acoustics and Remote Sensing (LARS) at Northeastern, in which she and her team of mostly graduate students focus on and explore acoustic, seismic and ultrasound remote sensing for military, ecology and commercial applications.
Saumitro Dasgupta, a junior electrical and computer engineering major who works in LARS, said the system aims to distinguish biological clutter from manmade objects like underwater vehicles.
“The focus now is to use the technology we have to determine how many fish actually are in a school of fish,” Dasgupta said. “With sonar, or radar, you can know that you hit an object, but you might not know how many objects you actually hit.”
Currently, most fishermen do not have access to this type of technology, the type that allows them to know just how many fish are in a school.
“It’s uncharted territory, really. It hasn’t been done before,” Dasgupta said.
This can be achieved through the use of acoustic color, by measuring how different colors respond to different frequencies.
“Red has a longer wave length and shorter frequency, while blue light has a shorter wave length and longer frequency,” Ratilal said.
With sound, different notes have different frequencies, leading observers to understand what objects they come in contact with.
“The nature of the return for a school of fish is much less constant than that of a manmade object,” Ratilal said. “Fish move around, manmade objects stay the same. You will receive a much more constant reflective energy.”
