Profs design AK47-locating 'smart dust' helmets
Satnav network node-lids backtrack bullets, ID weapons
"This is the AK-47 assault rifle, the preferred weapon of your enemy. It makes a very distinctive sound"
The nifty software can also reliably identify the calibre of all the flying bullets; and can even, in many cases, tell exactly what kind of gun fired them. It can reliably distinguish NATO 5.56mm rounds shot out of an M16 rifle from ones thrown by an M4 carbine, for instance. However, it can't separate M4s from M249 light machine guns - though the designers think it might be able to in future. Rather more importantly, it can easily tell an AK47 assault rifle - the weapon most commonly used to shoot at Western soldiers - from anything else, even a US-issue M240 firing ammo of the same 7.62mm calibre*.
Every node is also equipped with Bluetooth short-range data radio, for the purpose of sending the info to a display and interface. Ledeczi and his colleagues suggest that this might be a PDA or similar handheld gadget, but it ought to be possible to make the system work with a hands free heads-up display such as that included in the Land Warrior wearable soldier-smartphone rig. A helmet fitted with Ledeczi's system already knows exactly where it is and how it is oriented with respect to the gun muzzles, so it should be able to mark the positions of enemy shooters on a see-through visor or monocle without difficulty.
Squad leaders or platoon commanders, meanwhile, might rather see their enemies on a map or aerial photograph. Exploration quotes retired US army colonel Albert Sciarretta, now working as a Pentagon assessor, as saying that:
“A leader can use the information that this system provides to react tactically to enemy shooters in ways that limit the number of friendly force and non-combatant casualties. The ISIS system could be easily developed into an operational war-fighting system.”
The kit's even cheap: Ledeczi say that each set would cost only $1,000, as compared to existing systems selling for ten times as much. But nonetheless it seems to be stalled at present - nothing further has happened since trials on an Army range in 2007.
That may be because there are already a lot of competing acoustic gunshot spotters out there; it may be that the ISIS kit isn't actually all that great; there could also be concerns regarding available wireless spectrum, or enemy electronic tinkering. There's also a lot of interest these days in laser scanners which could detect the lenses of enemy snipers' telescopic sights before they had even fired.
Even so, you'd think that the light weight of the ISIS gear and its ability to work in the midst of confused urban gunfights rather than purely against single snipers in line-of-sight mode might make it stand out from the crowd. Its ability to pick out AK47s etc and ignore friendly weapons could even function usefully in avoiding friendly-fire incidents - and help in picking out primary enemy targets like machine guns or heavy sniper rifles. To be sure, it wouldn't work against anyone firing subsonic bullets: but that's pretty rare these days, and slow pistol or submachinegun rounds aren't much threat to well-armoured modern soldiers.
*Not too hard, as NATO 7.62mm is a much higher-powered cartridge than the Soviet 7.62mm used in AKs.
**Ignore the howler "a submachine gun like the AK-47", which seems to have originated with the scribe rather than Ledeczi's crew.