DARPA drone sensor array towed by drone ship

A towed sensor suite got a lift from an antisubmarine warfare (ASW) drone ship during a recent testing off the California coast.

The Defense Advanced Research Projects Agency said the first payload deployed by the unmanned ASW ship was its Towed Airborne Lift of Naval Systems (TALONS) sensor suite, which carries intelligence, surveillance and reconnaissance sensors up to altitudes ranging from 150 to 1,500 feet.

The goal of the DARPA research effort is to demonstrate that a towed airborne array can extend ISR sensor range well beyond mast-mounted gear. The prototype unmanned ASW ship is being tested under a program dubbed ACTUV (ASW Continuous Trail Unmanned Vessel).

DARPA said this week it demonstrated the towed sensor over two days with 90 minutes aloft each day. "Nested" at the rear of the unmanned vessel, the TALONS prototype deployed a parachute that lifted the array to an altitude of 1,000 feet. Onboard sensors and communications gear was tested during the flight before the prototype was reeled back into its nest.

While TALONS was deployed, the unmanned ship maneuvered at "operationally realistic speeds," DARPA said.

Program officials said the towed sensor array significantly improved the range of sensors and radios compared to mast-mounted gear. They cited a six-fold increase in the range of surface-track radar compared to a sensor operating at sea level. The discrimination range of an electro-optical/infrared scanner was doubled at 1,000 feet, they added, while the range of a commercial radio more than tripled.

"TALONS was our first chance to demonstrate hosting a real payload and showing the versatility of ACTUV to do a wide variety of missions for which it wasn't originally designed," Scott Littlefield, the DARPA program manager for the ASW ship program, noted in a statement.

DARPA envisions the unmanned ASW platform as a flexible "payload truck" for extending the range of ISR sensors and ship-based communications.

The TALON towed array is a kind of airborne variation on towed sonar arrays long used by the U.S. Navy for ASW missions. Towing sonar hydrophones behind ships and submarines helps reduce interference from the noise generated by the vessel itself.

The DARPA research is part of a broader effort to leverage unmanned aircraft and ships for surveillance and intelligence gathering. TALON sprang from a separate DARPA-Office of Naval Research effort called Tern aimed at developing an unmanned aircraft with vertical takeoff and landing capabilities.