Faced with a ballooning bill for aerial maritime surveillance, the Australian Customs Service has followed in the footsteps of the Defence Science and Technology Organisation and is field-testing network centric Unmanned Aerial Vehicles (UAVs) to keep an eye in the sky for unauthorised arrivals.

Comprising of the same Saab Aerosonde UAVs trialled by the DSTO during Australia's intervention in the Solomon Islands last year, the pilotless aircraft are currently undergoing trials off the Western Australia coast to determine suitability for long-haul surveillance missions.

Apart from providing video and still imagery of targets, the UAVs also offer a high bandwidth wireless networking capability for surface and airborne positioning and communications.

A DSTO spokesman said the aircraft were currently being evaluated for "electronic warfare, radar jamming, surveillance and intelligence gathering capabilities [and] to provide seamless network coverage and long-range network extension, regardless of the ground environment".

Chief of DSTO's electronic warfare and radar division, Dr Len Sciacca, said the aircraft offered a viable alternative to more expensive satellite communications.

"This UAV-based airborne node will give us the ability to provide line-of-sight radio capability across any terrain, essentially offering satellite quality communications without the associated cost," Sciacca said, adding the UAVs formed an integral part of networked battlefield automation.

If successful, the UAVs will contribute to projects under Defence Capability Plan including Joint Project 2072 (Battlespace Communications - Land), Joint Project 129 (Airborne Surveillance for Land Operations) and Land 125 (Soldier Combat System).

Running on premium unleaded petrol, the aircraft has a wing span three metres, weighs 15kg and can be launched from the back of a four-wheel drive.