Use the phone to track down the sniper

With the development of technology, there is no need to carry heavy machines to identify an assassin's hideout.

The US military is equipped with high-tech equipment to detect snipers, such as fixed machines installed in strategic locations. Now, the technology of searching for assassin gunmen has become much simpler, when civilian guards can also do it if they are equipped with Android phones.

A team of computer engineers at Vanderbilt University (USA) has built an inexpensive hardware, accompanied by software to turn any Android phone into a sniper detector. According to Gizmag, team leader Akos Ledeczi said they had assembled a sensor unit the size of a deck of western cards. When a bullet leaves the barrel, the instant sensor catches the sound and records the time of the shooting.

Mobile phones can help find snipers - (Photo: special-ops.org)

Next the data sent to the phone is pre-installed via a bluetooth connection. Combined with other phones also equipped with this component to form a system, users can determine the location that fired the gun. The idea is similar to ShotSpotter, a system being used in Seattle to track the location of the gunman.

Vanderbilt University system has two versions. First, only one microphone is needed for each sensor, but it will take at least 6 different phones to calculate the exact location of the shot. Meanwhile, the second approach requires 4 microphones per sensor, but only 2 phones are enough to locate the sniper.

This is because the devices take advantage of a unique feature of the gun shots: they produce two loud explosions. The first blast exploded from the muzzle, when the explosive gas pushed the bullet to the front to expand and create shockwaves. This resounding sound spilled in all directions and it was shaped like a sphere. And the bullet made a second explosion. While they often move at supersonic speeds, the explosion stops only at small bass sounds. The sound wave is now conical, with the bullet at the tip of this image.

Recording the time of emitting these two explosions can provide a sign that points to the point where this gunfire comes from, and when the data is collected at different characteristics, it allows the formation of a triangle Access the location of the perpetrator. Using a low-pitched sound from the bullet allowed the microphones to "hear" the gunshots at a longer distance, according to Ledeczi team scientist Janos Sallai.

At greater distances, spherical waves from the muzzle were distorted by obstructions on the ground, which was one of the reasons people were troubled when they heard gunshots. If only using the microphone equipped on the phone is still not enough, so American experts think of amplifier and sensor filter parts.

With new technology, civilian guards can protect customers with each team member equipped with a sensor. If the shot is fired, they can follow the trail and help the police catch the killer.