Sandia Sensor Has Potential To Help U.S. Military Eliminate 'Friendly Fire' During Combat

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 is recognizable to an attack aircraft as a "friendly." The device, tracked via aircraft radar, can be used to identify both U.S. and coalition forces during combat to avoid fratricide. During war, fratricide is the act of killing one's own soldiers.

Sandia researcher Lars Wells and a team of lab engineers have completed numerous tests and identified partners and potential customers for the sensor, which will be tested by the U.S. Army this fall.

The researchers have shown the sensor can work with multiple radars and multiple aircraft, Wells said.

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

Radar echoes

The sensor, dubbed by the Army as "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) reflections from the ground, it recognizes the tag's unique data signal and places an icon on the pilot's screen to alert him. The project has good system integration between tag and radar, Wells said, which is key to making it usable.

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

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, Wells said. "Developing the capability to identify friendly vehicles in battle will bring about a great reduction of fratricide."

The sensor can also assist battlefield situational awareness, he said.

"Many times during combat the military has to pull back from an attack plan because they don't know who is on ground," he said.

Wells said a future path of the project is to include tags on every soldier.

Keeping costs down

Sandia researcher Mike Murphy said 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," Murphy said. "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," Murphy said.

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, said Wells.

The current project is being 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's radar tag is one of a number of technologies being evaluated by the U.S. military to help reduce fratricide and improve situational awareness.

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

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