MS. REBECCA SHEIR
So last month, you might remember, on our chemistry show we brought you to Virginia's Fort Belvoir, where civilian scientists are using chemistry to protect soldiers from explosives. Well, we wanted to learn more about some of the technology these scientists are developing. As Matt M. Casey tells us, developing tools to find hidden explosives isn't exactly child's play, but it does involve a version of an old playground favorite, the sandbox.
MR. MATT M. CASEY
Every day, American soldiers use machines to find and neutralize mines in war-torn areas. Most of those devices make the transition from good idea to usable tool just outside of Washington, D.C.
MR. AARON LAPOINTE
Come on in to our massive sandbox here.
That's Aaron LaPointe, a researcher with the Army's Night Vision and Electronic Sensor Directorate inviting us in to the Directorate's mine lane facility. From the outside, the building looks like a large, long utility shed with a small, attached greenhouse. On the inside, 60-foot-long sandboxes hold six different colors of dirt. Near the door, a table holds an intimidating array of simulated mines.
We have different target sets, different types of targets, whether it is this artillery shell here, we have different types of rocks, different types of actual targets, clutter. That's an actual mine. All right. That's a anti-tank mine.
So when you say that's an actual mine, you mean…
No. There's no explosives in there. I'm sorry.
No, no, no. That's an inert mine.
So that would make that, please do not walk on mine lane sign over there just a little bit more intimidating.
Yeah, no, no, no.
To demonstrate why the facility exists, LaPointe and fellow researcher Cory Spiel (sp?) bury a mine in the kind of sand you would find at the beach. Then they sweep a metal detector over the surface.
As Cory goes along he's going to sweep it over an area he knows there's no targets in. And as you approach an area you'll hear a tone or audible difference.
That tone indicates that the detector found a small amount of metal. Most modern mines, LaPointe says, aren't very metallic. So it can be difficult for a metal detector to differentiate a mine from, say, a buried screw. But that's why this metal detector comes with a built-in ground-penetrating radar. Spiel switches the machine to radar mode and scans the area again.
So there are two different audible tones. So that way you can verify that, okay, this is a target that needs to be investigated. Whereas, something like a paperclip, you wouldn't hear this GPR tone.
With this device, LaPointe says, a properly trained soldier can reliably tell the difference between metal clutter and the real threat of a buried mine. While this piece of equipment looks like a typical, though rugged, metal detector, the gear LaPointe's team usually works on looks more like a mess of wires and duct tape.
What you're standing in here is our playground. We try to close the gap between the fundamental science, that works in a laboratory and then the actual sensor that the guy uses in the field.
To help close that gap the Directorate's sandboxes are equipped to replicate hundreds of different soil conditions. Each of the six different types of soil can be soaked and exposed to the sun, kept dark and dry or arranged to any configuration in between.
We do have pipes lining up and down each lane. And that allows us to adjust moisture content so we can basically spray water, have a lane that's completely soaked or if it's, you know, just a little bit of water, things like that.
Once the team has prepared the sand with any light, water, debris or rocks and of course, simulated mines, an overhead trolley carts experimental equipment over the surface at a walking pace.
So we can lower those to the ground. We can move them forward and backward. So we can test things that we bury or put inside the ground at different levels.
Whether that rig hauls radar, lasers or advanced metal detectors, this facility provides a first testing ground for concepts that will go on to further development and eventually reach the field and in significant numbers. Taking that into account, LaPointe says it's hard to see this oversized shed as just a giant sandbox.
It's not really just dirt, you know. It may look like that, but we realize the complexity of the problem, so we realize what it can provide us in improving the tools that we develop.
Thousands of those tools, such as the metal detector demonstrated for this story, have already been shipped to Iraq, Afghanistan and other conflict zones, helping to protect American soldiers deployed there. I'm Matt M. Casey.
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