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27 October 2015

Surveillance Drones Go to Sea

October 25, 2015

The American firm that makes the 1.1 ton Predator and 4.7 ton Reaper UAVs is developing a maritime patrol kit for the Reaper. It takes about 12 hours to install the maritime patrol kit which includes maritime search radar, sonobuoys and the ability to transmit data collected by the sonobuoy sonar back to land or airborne analysts for further processing. Also carried are Hellfire missiles that can be used against surfaced submarines or small warships. The maritime reaper would be able to fly to a spot more than 3,000 kilometers off shore, patrol the area for up to ten hours and then return. This new maritime patrol kit was developed in an effort to get a contract with the British Royal Navy to provide maritime patrol UAVs the British are seeking. This would provide a maritime patrol at less than half the cost of the larger U.S. Navy RQ-4B Triton UAV.

The Reaper already has some experience with maritime reconnaissance. In 2009 several MQ-9s were sent to the Seychelles (a group of 115 islands 1,500 kilometers from the east African coast) to aid in the anti-piracy patrol. This apparently was successful enough to encourage further work in this area. At the same time Israel was using a Predator size UAVs (the Heron) equipped with a synthetic aperture radar and onboard software to provide automatic detection, classification and tracking of what is down there on the waters off the Israeli coast. Human operators ashore, or on a ship or in an aircraft, are alerted if they want to double check something the software was programmed to consider suspicious. Operators used video cameras on the Heron to determine exactly what was down there. Also carried are sensors that track the sea state (how choppy it is). Israel still uses this version and has sold some to India.

Meanwhile the U.S. Navy has five of the 13 ton RQ-4B Triton UAVs in service since 2012. These are modified RQ-4B (Global Hawk) UAVs that began operational testing in 2010. The Triton was assigned to operating with a carrier task force at sea. Circling above the task force at 22,500 meters (70,000 feet), Triton monitored sea traffic off the Iranian coast and the Straits of Hormuz. Anything suspicious was checked out by carrier or land based aircraft, or nearby warships. The Triton aircraft can fly a 24 hour sortie every three days. The first production Triton was delivered in late 2012. In 2009, the first year of Triton testing consisted of 60 flights and over 1,000 hours in the air. The flights were over land and sea areas, even though the UAV sensors are designed mainly to perform maritime reconnaissance.

The Navy is buying the Tritons for over $60 million each. This version is larger (wingspan is 5 meters/15 feet larger, at 42.2 meters/131 feet, and it’s nine percent longer at 15.5 meters/48 feet) than the A model and can carry more equipment. To support that, there’s a new generator that produces 150 percent more electrical power. The RQ-4 has a range of over 22,000 kilometers and a cruising speed of 650 kilometers an hour.

The first three RQ-4Bs entered service in 2006. At 13 tons the Global Hawk is the size of a commuter airliner (like the Embraer ERJ 145) but costs nearly twice as much. Global Hawk can be equipped with much more powerful and expensive sensors, which more than double the cost of the aircraft. These “spy satellite quality” sensors (especially AESA radar) are usually worth the expense because they enable the UAV, flying at over 20,000 meters (62,000 feet), to get a sharp picture of all the territory it can see from that altitude. The B version is a lot more reliable. Early A models tended to fail and crash at the rate of once every thousand flight hours.

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