A new satellite system may allow firefighters to roll sooner on new forest fires. The system, developed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., links NASA's Earth science satellites to form what scientists call a virtual web of sensors. This sensor web has the ability to monitor the globe far better than any individual satellite.

When an imaging instrument on one satellite detects a fire or other hazard, it automatically instructs a second satellite with the ability to obtain photographs with greater detail to take a closer look. If those images reveal that a potential hazard does exist, the second satellite provides data to ground controllers, who then report the fire to forest officials.

The system essentially adds a response mechanism to existing fire detection, a first step to enabling users to specify the kind of data they want, such as forest fires or floods, rather than the traditional request that merely looks at a panorama of, say, central Oregon.

According to NASA, when an event occurs the system coordinates the desired reactions between different satellites. Using this sensor web method, investigators no longer have to rely on after-the-fact data analysis to determine what happened. The information can be used to rapidly respond to hazardous events such as forest fires.

For example, moderate-resolution imaging instruments that fly on both NASA's Terra and Aqua spacecraft observe the entire globe every day. The data is processed on the ground within hours of acquisition by the Rapidfire Center at the University of Maryland — College Park. If this processing detects a hot spot, scientific criteria can be used to redirect the Earth Observing 1 satellite to provide high-resolution images. When that information comes back to scientists, it's made available to forest officials to determine the appropriate response.

All this can now happen in 24 to 48 hours, compared to the previous typical lead time of 14 days for preplanned observations.