The Australian Defence Ministry has approved a new $175m deal for 18 RQ-7B Shadow 200 unmanned aerial vehicles (UAVs) and support systems to protect Australian troops in Afghanistan.

Shadow is powered by a 38hp engine with eight-hour endurance and a range of 100km. It can be launched from a trailer-mounted pneumatic launcher and retrieved using an arrester wire.

The UAV carries a suite of sensors that include high-resolution video and still cameras, ultra violet sensors and laser direction finders.

The vehicle also provides complete autonomy to troops and supplies live footage and data from the aircraft in real time on ground terminals.

The US-built Shadows will be used for battlefield surveillance, reconnaissance and target acquisition.

The deal also includes two support systems, ground vehicles, training packages and through-life support.

Australian Defence Minister John Faulkner said the Shadow 200 system would provide the Australian Army with a proven tactically mobile TUAV system.

He said the Scan Eagle UAV would remain in service until the Shadow 200 was delivered.