Hugh Pickens writes: "A new system developed by engineers at Vanderbilt University can display the location of enemy shooters in three dimensions and accurately identify the caliber and type of weapons they are firing by turning their combat helmets into "smart nodes" in a wireless sensor network. The system relies on the sound waves produced when a high-powered rifle is fired which have distinctive characteristics to allow the nodes to pick them out from other loud noises and track them back to their source. The system combines information from a number of nodes to triangulate on shooter positions and improve the accuracy of its location identification process. "It's strong points are that it isn't limited to locating shots fired in direct line-of-sight, it can pick up multiple shooters at the same time, and it can identify the caliber and type of weapon that is being fired." says Retired U.S. Army Lieutenant Colonel Albert Sciarretta, who assesses new military technologies in urban environments for DARPA. Each node in the system costs about $1,000 to construct using currently available commercial hardware. "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," Sciarretta adds."