Eliminating friendly fire

A device to help eliminate friendly fire during military combat has been created by engineers at the US National Nuclear Security Administration’s Sandia National Laboratories.

Sandia engineers have created a radar tag sensor that is mounted on military vehicles and is recognisable to an attack aircraft as ‘friendly.’ The device, tracked via aircraft radar, can be used to identify both US and coalition forces during combat to avoid fratricide.

The researchers have shown the sensor can work with multiple radars and multiple aircraft, said Sandia researcher Lars Wells. The US Army will test the sensor this autumn.

The sensor, dubbed ‘Athena’ by the Army, 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 receives reflections from the ground, it recognises 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.

Sandia researcher Mike Murphy believes that costs incurred deploying Athena can be kept down by making the tag work 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.’

‘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 concluded.