CCTV.com - CNTV English - CCTV News

U.S. researchers use smartphone app to measure particulate air pollution

09-21-2010 09:40 BJT

LOS ANGELES, Sept. 20 (Xinhua) -- University of Southern California (USC) computer scientists said on Monday they have found a way to combine smartphone resources with a novel application that allows the phones' users to help monitor air quality.

The basic principle of the Visibility app is simple, according to the paper documenting the work by USC computer science professor Gaurav Sukhatme.

The user takes a picture of the sky while the sun is shining, which can be compared to established models of sky luminance to estimate visibility. Visibility is directly related to the concentration of harmful "haze aerosols," tiny particles from dust, engine exhaust, mining or other sources in the air. Such aerosols turn the blue of a sunlit clear sky into gray.

The visibility/pollution models are based on the viewing geometry of the image and the position of the sun.

The Visibility app works because modern smartphones contain a rich set of sensors that include cameras, GPS systems, compasses and accelerometers, in addition to the powerful communication capabilities that are inspiring a slew of intelligent phone applications ranging from personal health monitoring to gaming and social networking.

Sameera Poduri, a postdoctoral researcher in Sukhatme's lab, explained that the accelerometer in the phone -- the sensor that tells how the user is holding the phone, determining whether it displays information vertically or horizontally -- can "guide the user to point the camera in exactly the right direction."

The system potentially can help fill in the many blanks in the existing maps of air pollution. Conventional air pollution monitors are expensive and thinly deployed, Sukhatme noted. Many California counties have no monitors at all.

The system has been tested in several locations, including Los Angeles and Phoenix, Arizona.

So far the results are promising, but they indicate that several improvements are possible.

"We're sure we can improve it if we get people trying it and testing it and sending data," Sukhatme said.

Editor:Yang Jie |Source: Xinhua

Hot Videos view more

The celebrations are still continuing as the victorious coach, Joachim Loew, has been honored for his achievement in his hometown of Freiburg.
Germany coach Loew honored in hometown of Freiburg

Chinese men´s national team continued its preparations for next year´s Asian Cup, as they managed a one-all draw against visitors Jordan during a football friendly in Harbin, the capital city of Northeast China´s Heilongjiang Province.
China held to 1-1 draw by Jordan

The defending world champs came into the contest with a perfect 6-and-oh record, but they would be in for a tough first half before opening things up in the second.
USA beat Slovenia 119-76 in quarter-finals

Hot Stories more

UK authorities believe killer of James Foley is a British national

Across the UK the hunt is on for James Foley’s killer, who authorities believe is a British national. As Richard Bestic reports from London, Prime Minister David Cameron cut short his summer break to lead his government’s response.

Israeli war jets renews Gaza strike as truce talks stalled

Three Palestinians were killed and 40 others wounded in the intensive Israeli war jets´ airstrikes on the Gaza city on Tuesday night, shortly before an end of a 24-hour ceasefire in the Gaza Strip,

Missouri police arrest dozens after violent night

As the protests in the town of Ferguson, Missouri turned violent with police facing ´heavy gunfire´ from some ´criminal elements´, cops fired tear gas, stun grenades and arrested 31 demonstrators on Monday night.

Picture in news more

More Video News

Choose TV Program