Because knowing which way to jump is pretty important, the British Army is getting a new system to find where enemy artillery is coming from. Built by Leonardo UK, the SONUS Acoustic Weapon Locating System uses sound analysis to locate enemy guns.
If you've gone out in the woods, odds are at some point you heard something go bang. How you react to that depends, in large part, on where that bang came from. If it's coming from ahead, it might just be someone on a farm hunting pheasant a mile away. If it's from the right, it's from the deep woods and over the hills and no problem. To the left, it's coming from town and might be more concerning because bangs aren't supposed to be there. If it's coming from behind, it might be something very close and a very bad problem.
The same thing goes for soldiers on the battlefield, except that there, bangs tend to get a lot more attention a lot faster. That's because such a report means that an artillery shell is incoming. The question of where the shell will land answers itself quickly, but soldiers also want to know where that shell came from.
Historically, that wasn't too hard to answer. For one thing, the way armies deployed for battle meant that just having a scout on a hill was enough to spot artillery setting up. Even if the enemy decided to hide their guns, the moment they fired they'd give themselves away by the thick clouds of gunpowder smoke they ejected.
Today, things are very different. Guns are designed to blend into the landscape. They're mobile to one degree or another, so they can fire a round, pack up, and run before the other side can return fire. It's called "shoot and scoot." That means that finding where the guns are – and fast – is of vital importance for survival.
One way of doing this is by acoustics. In other words, listening to where the sound of the gun firing is coming from. That seems simple, but I know from experience that I can only nail down a rifle shot to somewhere within 180 degrees.
What's needed are two things. First, understanding what the sound is and, second, being able to locate it.
SONUS is a passive system that listens for three things coming from an artillery or mortar piece. The first of these is the muzzle blast, which is the expansion of gases inside the gun barrel. The second is the supersonic crack that's the result of the Mach cone shockwave generated by the projectile traveling faster than the speed of sound. The third is the sound of the shell hitting and exploding.
By analyzing the acoustic signature of these three things to tell one type of weapon from another, it can tell a gun from a mortar from a rifle. SONUS can then locate the source using sensors set in several locations and applying triangulation. That's exactly the same principle mariners use to pinpoint a ship or a landmark by taking compass bearings from several different positions. By drawing the bearings on a chart, where they intersect is a close approximation of the target's position.
Systems like this have been around for a couple of decades, but SONUS is claimed to advance the concept by incorporating GPS into the location process. It is also 70% lighter than Leonardo’s previous HALO system and can be put into operation in under three minutes.
The Ministry of Defence is particularly keen to note that SONUS will be deployed with the British Army’s 5th Regiment Royal Artillery five years ahead of schedule, citing it as an example of improvements in the military procurement process as part of Britain’s military buildup.
"Leonardo has over 40 years of experience in passive acoustic weapon-locating technology, with battle-proven systems that have seen operational use with over 13 Armed Forces – many of whom are NATO members," said Olly Manning, Vice President Mission Systems at Leonardo. "We are looking forward to working in partnership with the British Army to ensure SONUS provides them with an accurate, robust and reliable passive detection system that will keep our Armed Forces safe – now and into the future."
Source: Ministry of Defence
