Military Helicopters May Get Gunshot Location System
- By Nathan Hodge
- March 24, 2010 |
- 4:49 pm |
- Categories: Army and Marines
Military helicopters have sophisticated electronic countermeasures to detect and defend against surface-to-air missiles, by jamming or fooling the seekers that guide the missiles to target. Now the Pentagon’s far-out research arm wants to take things a step further, by protecting against unguided — but equally dangerous — small arms fire.
In testimony yesterday, Regina Dugan, the new head of the Defense Advanced Research Projects Agency, described a new acoustic sensor the agency was developing to alert aircrews to ground fire.
The system — called HALTT, for Helicopter Alert and Threat Termination — is a hostile-fire indicator that would give the pilot a warning of attack, and pinpoint its origin. It would work by detecting the distinct acoustic signature (or “crack”) of a bullet as it passes through the air. It would then indicate the shooter’s position. HALTT, Dugan said, “would make it very dangerous to shoot at U.S. forces — because the first shot may very well be the adversary’s last.”
Dugan also gave an interesting statistic: Incoming small arms fire, she said, accounted for 85 percent of hostile engagements against helos. A prototype of the system has been installed on an Army UH-60 Blackhawk helicopter, and Dugan said the military was planning to deploy several systems to Afghanistan for real-world evaluation.
Gunshot location systems like Boomerang are already in service on some military vehicles. Integrating this system on an aircraft represents a logical — and rapid — next step. Dugan said: “From funding allocation to live fire test completion, this effort took an unprecedented 5 months and will be fielded in less than a year from identification of the need.”
[PHOTO: U.S. Department of Defense]
What about combining that with some lightweight armor technology that would stop small arms fire? I guess that it would increase robustness against shrapnel from rocket warhead explosion to some extent, but that might be much more complex because of the nature of antiaircraft warheads. They are basically expanding steel loops driven by explosives, working like saws against the airframe.
85% small-arms fire. But what percentage of that actually disables the Helo or a crew member?
Considering that most ammunition that would be used against a helicopter would be travelling at supersonic speeds (correct me if I’m wrong), the bullets would reach the chopper before the crack sound. Surely that would render an acoustic sensor useless unless it was just someone with poor aim taking the odd pot shot with an AK at a very long range. Perhaps that is the target, but if so, it seems like just another expensive technical solution that would easily by rendered useless by a change of weapon or tactics.
@Guttersnipe - good point. Perhaps working on lightweight small-arms stopping aircraft armor would be a better use of money. It would be ideal if the armor could double as structural material.
@Guttersnipe, I got the impression that the systems were about stopping the second shot, not the first.
I can foresee the enemy going into battle with a lot of stereos, turned up to high volumes and playing noise (noise as in sounds with random acoustical patterns). Can’t really trace gunfire sound to a particular location if all you are getting is loud noise from many locations.
Or an even more sinister method to throw a wrench in this plan would be to give stereos to groups of women/children. Each of those stereos would be playing AK-47 gunfire. If a few groups of innocents do that, it would confuse the gunners or at least distract them as they would have to see the target and realize its a bunch of innocents.
Maybe a quick triggered gunner might fire, killing the innocents and destroying the “hearts and minds” campaign that is critical in today’s fourth generation warfare.
As others have mentioned above, there are methods or tactics to get around this thing. You just need a bit of creativity and bravery.
Imagine if they had this in Vietnam:no more hiding under the canopy and firing even a single round at US forces in the air without getting instantaneous deadly accurate return fire. And no, playing gunfire sounds from speakers on the ground would not work against this system as it apparently listens for the noise a supersonic object[the bullet] makes as it flies past. It looks as if the more accurate a shot is, the more accurate the system could pinpoint the ground location of the shooter.
People, its the pressure wave of the bullet (very high dB), not the actual sound/noise (low dB) you are talking about. To get the same pressure wave reading of a bullet passing by a helo from a set of speakers on the ground, you’d have to be playing AK “noise” from a massive LRAD, and I mean massive enough that it’ll be taken out long before Helo’s get anywhere near it.
Don’t get me wrong, I’m not flat out buying into the DARPA party line, but…don’t you think it’s likely they thought of things like dudes with boom-boxes? Besides, since the pressure-wave created by something traveling at supersonic speeds is following the object, the “map” of the shockwave wouldn’t be stationary like the pressure-wave created out of a speaker - the system could “see” it moving, I’d expect, and disregard the filler noise. But I’m totally guessing here. (shrug)
Here’s my guess to all the naysayers below: I suspect DARPA knows a thing or two more about this than you armchair warriors.
Sit on your helmets, just in case.
@ccL1,
If this is an adaptation of the acoustic sniper finder and countermeasure which BBN cooked up for Iraq, then increasing the noise profile with music and such wouldn’t help, because the percussion from a bullet is spectrally distinctive.
1. Boom boxes will not confuse this system.
2. Blackhawks and Apache’s are already armored but you can only do so much with armor.
3. Even with the armor you still have windows, open doors, and folks getting in and out.
3. The idea is that if the shooter will shoot at a helicopter he will shoot at a guy on the ground or a ground vehicle as well.
4. You shoot at a Blackhawk or Apache then you are volunteering to be a target yourself. Then next step would be to have a turret that would quickly target the shooters location and allow the gunner to shoot or not.