Want to See More Sea? DARPA Has TALONS For That

Detecting things at sea using radar has a limitation - most sensor can't see around curves - and the surface of the roundish Earth curves limiting detection ranges of objects past that curve.

One way around this limitation has been to mount sensors as high as possible on a ship, whether those sensors are lookouts in crow's nests or radar mounted at the top of a mast.

Since sensor altitude makes a difference, it is very interesting to see what DARPA is playing with in ACTUV Unmanned Vessel Helps TALONS Take Flight in Successful Joint Test:

DARPA’s Anti-Submarine Warfare (ASW) Continuous Trail Unmanned Vessel (ACTUV) program has developed and built a technology demonstration vessel that is currently undergoing open-water testing off the coast of California and recently set sail with its first payload: a prototype of a low-cost, elevated sensor mast developed through the Agency’s Towed Airborne Lift of Naval Systems (TALONS) research effort.

ACTUV seeks to lay the technical foundation for an entirely new class of ocean-going vessel—one able to traverse thousands of kilometers over the open seas for months at a time, without a single crew member aboard. Potential missions include submarine tracking and countermine activities. Towed behind boats or ships, TALONS could persistently carry intelligence, surveillance, reconnaissance (ISR), and communications payloads of up to 150 pounds between 500 and 1,500 feet in altitude—many times higher than current ships’ masts—and greatly extend the equipment’s range and effectiveness.
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While aloft, TALONS demonstrated significant improvements to the range of the sensors and radios it carried compared to mounting them directly on a surface vessel. For example, TALONS’ surface-track radar extended its range by 500 percent—six times—compared to its range at sea level. Its electro-optical/infrared scanner doubled its observed discrimination range. The TALONS team plugged in a commercial handheld omnidirectional radio; that radio’s range more than tripled.

Expanding the ranges of detection through use of unmanned vessels is vital to protecting those higher value units that do contain humans.



UPDATE: Yes, adding altitude to ship sensors is not a new idea - see the Coast Guard's sea based  aerosat program from the 1980s:

During the 1980s as a result of the increased illegal traffic of narcotics and migrants in the Caribbean, the Coast Guard established the Mobile Aerostat Program. It consisted of two shore-based units located in Key West and Miami, Florida. The units were comprised of two teams per vessel (total of five) which alternately deployed aboard Sea Based Aerostat (SBA) Platforms. Aerostats were unmanned lighter-than-air aircraft which mounted sophisticated radar and other surveillance equipment. The MAP mission was to provide continuous air and surface surveillance for other law enforcement units working in the same geographic area of responsibility. SBAs normally worked in conjunction with high and medium endurance cutters and patrol boat class vessels. Successful operations were conducted with other U. S. and foreign naval forces. From 1984 to the program's decommissioning on 31 March 1992, the Aerostats provided target information resulting in numerous drug seizures and illegal alien interdictions.

Of course, that was before we had cool, unmanned vessels to tow sensors around.

Maritime Security: Robo Marine Security Helicopters - Testing Against Pirates

ONR image

Another tool in the maritime security kit- if it works - as set out in this Office of Naval Research press release, "Pirates, Beware: Navy’s Smart Robocopters Will Spy You in the Crowd":

Navy unmanned aircraft will be able to distinguish small pirate boats from other vessels when an Office of Naval Research (ONR)-funded sensor starts airborne tests this summer, officials said April 5.

Fire Scout UVAS

Called the Multi-Mode Sensor Seeker (MMSS), the sensor is a mix of high-definition cameras, mid-wave infrared sensors and laser-radar (LADAR) technology. It will be placed on a robotic helicopter called Fire Scout. Carrying advanced automatic target recognition software, the sensor prototype will allow Fire Scout to autonomously identify small boats on the water, reducing the workload of Sailors operating it from control stations aboard Navy ships.

“Sailors who control robotic systems can become overloaded with data, often sifting through hours of streaming video searching for a single ship,” said Ken Heeke, program officer in ONR’s Naval Air Warfare and Weapons Department. “The automatic target recognition software gives Fire Scout the ability to distinguish target boats in congested coastal waters using LADAR, and it sends that information to human operators, who can then analyze those vessels in a 3-D picture.”

Navy-developed target recognition algorithms aboard Fire Scout will exploit the 3-D data collected by the LADAR, utilizing a long-range, high-res, eye-safe laser. The software compares the 3-D imagery to vessel templates or schematics stored in the system’s memory.

“The 3-D data gives you a leg up on target identification,” said Dean Cook, principal investigator for the MMSS program at Naval Air Warfare Center Weapons Division (NAWCWD). “Infrared and visible cameras produce 2-D pictures, and objects in them can be difficult to automatically identify. With LADAR data, each pixel corresponds to a 3-D point in space, so the automatic target recognition algorithm can calculate the dimensions of an object and compare them to those in a database.”

The algorithms have been successfully tested in shore-based systems against vessels at sea. The software is being integrated into a BRITE Star II turret by a team from NAWCWD, Raytheon, FLIR Systems, BAE Systems and Utah State University for airborne testing aboard a manned test helicopter. The flight assessment will be conducted against groups of approximately seven small boats in a military sea range off the California coast later this summer.

Sounds cool. Hope it works in the real world.