Tag-on sensor- Eliminating 'friendly fire' during combat
Lars Wells displays radar tag sensor prototype. (Photo by Randy Montoya)
Full size image available here.
Building on more than 10 years of research and development, Sandia engineers have created a radar tag sensor that can be mounted on military vehicles and is recognizable to an attack aircraft as a "friendly." The device, tracked via aircraft radar, can be used to identify U.S. and coalition forces during combat to avoid fratricide -- the act of killing one's own soldiers in combat.
Fratricide is also referred to as "friendly fire" in some cases.
Lars Wells, manager of Sandia's Radar and Systems Analysis Department, and a team of Sandia engineers have completed numerous tests and identified partners and potential customers for the sensor, which will be tested by the Army.
One of the selling points is that the researchers have shown the sensor can work with multiple radars and multiple aircraft, says Wells.
"It is mature enough to consider as a solution now and for the long term," he says.
The sensor, dubbed "Athena" -- protector of the troops -- by the Army, is not a radio transmitter that broadcasts a signal for the aircraft to receive. Instead, it is a sensor that creates synthetic radar echoes. The probing radar picks up the sensor signal in the same way it picks up radar echoes from tanks, trucks or other objects.
In general, radar transmits a pulse of energy then looks for the reflections of that energy from objects on the ground. The tag sees the radar's transmitted pulse and sends it back to the radar, except it adds a little bit of data to the reflection.
As the radar picks up reflections from the ground, it looks for that unique data signal. Once the radar sees the data on an echo, it acknowledges the tag by placing an icon on the pilot's screen to alert him. The project has good system integration between tag and radar, Wells says, which is key to making it usable.
According to the Department of Defense, 24 percent of the 146 American battle deaths during Operation Desert Storm were by so-called friendly fire. Fifteen percent of the 480 wounded were also caused by fire from friendly forces. Historically, fratricide has accounted for 10-15 percent of wartime casualties.
These incidents have long been a problem during war, says Wells. "Developing the capability to identify 'friendly' vehicles in battle will bring about a great reduction of fratricide."
The sensor has shown the potential to truly save lives on the battlefield, "But it can also assist in battlefield situational awareness," he says. "Many times during combat the military has to pull back from an attack plan because they don't know who is on ground."
Wells says a future path of the project is to include tags on every soldier.
Keeping costs down
Longtime Sandia tag expert Mike Murphy says one way of keeping costs down is to make the tag work easily with existing systems.
"The aim of affordability is a big factor of the project," says Murphy, who is manager of the Labs' Special Radars and Communications Systems Department. "By adding tagging to existing radars, we don't need to build new equipment for the aircraft."
Costs can also be kept to a minimum by partnering with industry and with various military agencies.
"Our industrial partners will be able to take this technology and drive the cost down quickly so that it is affordable for every Army vehicle and Air Force fighter jet," says Murphy.
Some recent development has been supported by the Department of Energy's Nonproliferation Office, which has an eye toward using the technology to track proliferants. In fact, this application was how Sandia started to create what became Athena, says Wells.
The current project is being sponsored by the Army's Communication Electronics Research, Development, and Engineering Center, which is staging a large exercise this fall to demonstrate the tag system for high-ranking officers and regular soldiers alike.
"Sandia was the only developer that could ready a tag to support the short deadline," says project leader Rick Ormesher, a project engineer. "We were able to do an initial demonstration for the Army in January 2003 with only a few months worth of effort."
The success of that initial demonstration helped lead to the current effort, he says.
"We are really excited about the prospect of deploying this technology and seeing it make an impact," says Wells.
In addition to a dozen different Sandia researchers in five departments, the project is also teaming with General Atomics Corp. and Sierra Monolithics Inc.