Sandia LabNews

Sandia-developed sensor could help eliminate friendly fire casualties

Sandia sensor has potential to help US military eliminate ‘friendly fire’ deaths during combat

A device to help eliminate "friendly fire" during military combat has been created by Sandia engineers.

Building on more than 10 years of research and development, Sandia engineers have created a radar tag sensor that is mounted on military vehicles and which is recognizable to an attack aircraft as a "friendly." The device, tracked via aircraft radar, can be used to identify both US and coalition forces during combat to avoid fratricide. During war, fratricide is the act of killing one’s own soldiers.

Lars Wells (2344) 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 this fall.

One of the selling points is that the researchers have shown the sensor can work with multiple radars and multiple aircraft, says Lars.

"It is mature enough to consider as a fratricide and situational awareness solution now and for the long term," he says.

Radar echoes

The sensor, dubbed by the Army "Athena" — protector of the troops — is not a radio transmitter that broadcasts a signal for the aircraft to receive. Instead, the sensor creates synthetic radar echoes, so that the radar picks up the sensor signal in the same way it picks up radar echoes from tanks, trucks, or other objects.

In general, the 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 (or echo).

As the radar picks up (or receives) all of the reflections from the ground, it looks for that unique data signal. Once the radar sees that data on an echo it knows it is looking at a tag, and places an alert icon on the pilot’s screen. The project has good system integration between tag and radar, Lars says, which is key to making it usable.

"Generally the radar will be nearly as accurate in locating a moving tag as it would be in locating any other moving object," he says.

Eliminating fratricide

According to the Department of Defense, 24 percent of the 146 American battle deaths during Operation Desert Storm were by friendly fire. A further 15 percent of the 480 wounded were also by friendly fire. Historically, fratricide accounts for 10-15 percent of wartime casualties.

"Blue-on-blue" incidents have long been a problem during war, says Lars. "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 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 the ground."

Lars says a future path of the project is to include tags on every soldier.

Keeping costs down

Mike Murphy (2346), Sandia’s longtime tag expert, says one way of keeping costs down is by making the tag work easily with existing systems.

"The aim of affordability is a big factor of the project," says Mike. "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 Mike.

Technological support

Recent underlying development has been supported by DOE’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 Lars.

The current project is sponsored by the Army’s Communication Electronics Research, Development, and Engineering Center (CERDEC), which is staging a large exercise this fall that will demonstrate the tag system for high-ranking officers and regular soldiers alike.

"Sandia was the only developer that could ready a tag to support their short deadline," says project leader Rick Ormesher (2344). "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, says Rick.

"We are really excited about the prospect of deploying this technology and seeing it make an impact," says Lars.