Soldiers' helmets serve as sniper location system

The use of acoustics to identify and locate the source of enemy fire — whether on the battle field or the streets of a city — is growing in popularity (see below links to several stories we have written on the subject). Researchers have now taken acoustic location to the next level. Imagine a platoon of soldiers fighting in a hazardous urban environment who carry personal digital assistants that can identify and display the location of enemy shooters in three dimensions and accurately identify the caliber and type of weapons they are firing. David Salisbury reports in Vanderbilt University’s Exploration Magazine that engineers at Vanderbilt University’s Institute for Software Integrated Systems (ISIS) have developed a system that can give soldiers just such an edge by turning their combat helmets into “smart nodes” in a wireless sensor network. ISIS developed this technology with the support of the Defense Advanced Research Project Agency (DARPA) and the university has patented two of the system’s key elements.

Like several other shooter location systems developed in recent years — for example, QinetiQ’s EARS battle sniper location system — the ISIS system relies on the sound waves produced when a high-powered rifle is fired. These acoustic signals have distinctive characteristics that allow the systems to pick them out from other loud noises and track them back to their source. Current systems, however, rely on centralized or stand-alone sensor arrays. This limits their accuracy and restricts them to identifying shooters at line-of-sight locations.

By contrast, the ISIS system combines information from a number of nodes to triangulate on shooter positions and improve the accuracy of its location identification process. It also uses a patented technique to filter out the echoes that can throw off other acoustic detection systems, explains Akos Ledeczi, the senior research scientist at ISIS who heads up the development effort. “When DARPA gave us the assignment of creating a shooter location system using nodes with very limited capabilities, they didn’t think we could solve the technical problems,” Ledeczi admits. “At first, I didn’t think we could do it either, but we figured out how to make it work!”

Retired U.S. Army Lieutenant Colonel Albert Sciarretta, who assesses new military technologies in urban environments for DARPA, is one of the experts who is impressed by the ISIS system: “It’s strong points are that it isn’t limited to locating shots fired in direct line-of-sight, it can pick up