The idea for the network actually began prior to the tragic consequences of 9/11, when two men at the lab put their heads together and came up with an interesting idea. Jim Kulesz and Dick Reid figured there ought to be another use for the cell phone towers that were springing up all over the place.
Oak Ridge was already developing a new generation of sensors, as were many other institutions, but to be useful they needed to be integrated into a communications network. Cell phone towers seemed a logical choice because the data could be immediately transmitted to wherever it was needed, and the towers tended to be concentrated near population centers.
After 9/11, the idea moved into high gear when it caught the attention of Congressman Zack Wamp, R-Tenn., who wrestled enough money out of Washington to establish a "proof of concept" network. That led to the current program of sensors spread across a significant geographical area, and Strand says it did, indeed, prove the concept.
The project evolved beyond cell towers, putting sensors in the heart of cities, where they are most needed.
"We actually have a system that works and could be deployed," Strand says. That's a bit of a change of pace, by the way, for a laboratory that usually finds itself on the cutting edge of science and technology. Most of this program is based on off-the-shelf technology.
Breath Mint Alert
In a sense it's an idea that is ahead of its time. Strand admits there are a lot of false positives in the system, because even the most advanced sensors can sometimes be fooled by a harmless substance. Even the "essence of wintergreen," which provides the flavor in some breath mints, has set off sensors during trial runs, he says.
That introduces the risk of shouting wolf too often, but Strand argues that even the emergency phone number of 911 gets a fair share of false reports, and it's still very useful.
A network of sensors, however, should make it possible to reduce that problem because the data from multiple sensors should reinforce each other if the threat is real.
"What we are learning is how to pattern the information so that when you see certain kinds of spikes, along with other kinds of information, you can limit the false positives," he says. Does another nearby sensor also detect the presence of the same chemical? Is there a warehouse nearby where that chemical is routinely used? Does the weather sensor show the substance moving into the wind, instead of with it?
Such a program would have applications far beyond the threat of terrorism. Industrial accidents account for most exposures to dangerous chemicals in this country, and SensorNet could detect those as well.
So the folks at Oak Ridge will push ahead. Their immediate challenge, as Strand puts it, is pretty basic to the success of the project.
"How do you take existing capabilities, even though they may not be perfect, and build and design a system that could be rapidly deployed and supported throughout the United States to give us a level of protection that we don't currently have?"
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.