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Revealing radar

U.S. Navy partially lifts shroud on insurgent-tracking system

Jan. 1, 2009 - 03:45AM   |  
By Keith Button   |   Comments
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A U.S. Navy radar developed in secrecy for tracking targets at sea has been playing an important role on land because of its ability to track objects smaller than trucks or cars. One knowledgeable official says the radar is one of the "groundbreaking" insurgent-hunting technologies referred to, though not by name, in Bob Woodward's latest book, "The War Within."

The Littoral Surveillance Radar System, or LSRS, was "born black" and developed as a "deeply, deeply classified system," according to a knowledgeable official who was not authorized to speak for the program. LSRS operates from P-3C Orions and can be used to track targets on land or sea, and to provide images of those targets to intelligence analysts and commanders. Boeing, Raytheon and L-3 Communications collaborated on it.

The secret of LSRS is its fidelity. Other airborne radars, including the 17-year-old Army-Air Force Joint Surveillance and Target Attack Radar System (Joint STARS) aircraft, can track cars and trucks through clouds and at night. Because of the wars in Afghanistan and Iraq, the Pentagon pushed the U.S. defense industry to develop radars capable of detecting and tracking people. In 2008, Northrop Grumman reported that an experimental airborne sensor called the Vehicle and Dismount Exploitation Radar had detected people during a flight over a test range in Maryland. Northrop Grumman says that radar would be small enough to fit on a Predator UAV.

The Navy has implied, but not confirmed, that LSRS can see individuals: "We can track vehicles and items smaller than that," said Capt. Scott Anderson, the LSRS program manager. "It can be sized for what it needs to be sized for."

The Navy officially acknowledges only that it has used the radar in the "global war on terror."

The ISR expert said the military has, in fact, used LSRS in Iraq and that it is one of the "groundbreaking programs" credited in the Woodward book with helping turn the tide of the war.

A Pentagon spokesman said the department "would not engage" in discussion of LSRS and the Woodward book.

The motivations of LSRS advocates to reveal some information about the radar are not entirely clear. Officially, the Navy explains that it is part of the normal progression for most technologies that begin as classified when they are new, and then become discussed more publicly as they get older.

Part of the reason for opening up may be the Navy's recognition that information about the radar system's use has already leaked. In 2005, civilian observers began to report on the Internet that they had spotted P-3C Orions with long pods attached to and extending down nearly half of the belly of the aircraft. Anderson confirmed that the Navy began flying the radar for operations that year. Also, advocates for various ISR programs have been competing for the additional Pentagon dollars under Defense Secretary Robert Gates' initiative to increase the number of intelligence resources in the field.

As its name implies, LSRS was originally designed for monitoring vessels on near-shore littoral waters, but the military pressed it into service in Iraq, the ISR expert said. The Navy did not start flying LSRS radars over the water until 2007, Anderson said.

For its work on land, LSRS has a ground moving target indicator, or GMTI, mode and a synthetic aperture radar mode. GMTI tracks moving objects by detecting the shift in radar frequency as the signal bounces back to the aircraft from a moving target. That shift makes moving objects pop relative to the still background. SAR is the imaging mode, providing high-resolution images similar to photographs.

At sea, LSRS also has a ship-tracking mode maritime moving-target indicator and an imaging mode, called inverse SAR, which uses the motion of a target ship to create the image.

LSRS can pass its targeting information to ships, ground stations or other aircraft through Tactical Common Data Link format or Link 16 format, which requires a line-of-sight connection.

If an image of a target can be generated, then that picture can also be passed along, Anderson said. Typically, a liaison officer attached to the ground units involved in an LSRS mission will fly with LSRS crew and stay in radio contact with those units to help feed them the tracking and imaging information.

P-3C Orions fly with a crew of 11, including the personnel responsible for manning the LSRS system. While the systems were originally intended to support Navy and Marine Corps operations, the thrust toward joint operations in the post-Sept. 11 age has removed those limitations. LSRS data has helped with Army, Air Force and intelligence agency surveillance missions, Anderson said.

The supplemental war budget for 2008 included funding for five additional LSRS radars. Anderson would not say how many LSRS radars exist, but various reports have put that number at seven. The first new LSRS from the supplemental appropriation should be fielded in 18 to 24 months, with subsequent systems coming online every few months after that, Anderson said.

According to the Navy, it plans to use a follow-on to the LSRS radars, called Advanced Airborne Sensors, on P-8A Poseidon aircraft. As with LSRS, those sensors will provide high-resolution, near-real-time radar surveillance along with added modes, such as submarine mast and periscope detection.

The LSRS radars are in such high demand that it has been difficult for the Pentagon to experiment with how they might be used in conjunction with other weapons. The Navy delayed two flight tests in Florida in which missiles were to receive LSRS targeting data. The radars were needed elsewhere.

LSRS systems "are a national asset. The testing community becomes a second priority when an LSRS is needed for real-world operations, and I'll leave it at that," said Navy Capt. Mat Winter, who hopes to adapt precision missiles to receive updates from sensors including LSRS. Winter had an LSRS-Standoff Land Attack Missile test planned for late 2008, depending on availability.

The Navy says it tested LSRS for more 2,800 hours before calling the sensor into action in 2005.

LSRS is conceptually similar to Joint STARS. It is a wide-aperture active electronically scanned array (AESA) surveillance radar. AESA radars are solid-state, without moving parts, and include thousands of transmitter/receivers that track a high number of targets at one time. Certain types of AESA radars can also jam radio signals or damage the electronics of aircraft or missiles, but there is no evidence that the U.S. has used LSRS for that purpose.

Besides the AESA radar, LSRS also includes data storage, display and control hardware.

The Navy began funding work on LSRS in the mid-1990s, inspired by the success of the Air Force-Army Joint STARS aircraft in the 1991 Persian Gulf War. Joint STARS was taken out of its testing phase to play an integral part in the war, mapping the so-called "Highway of Death" as the Iraqis pulled out of Kuwait.

At the time, the Navy already had systems that pointed to specific targets, but had a need for a wide-area sensors to aid in targeting and in developing situational awareness over a large battlefield, Anderson said.

LSRS does not provide 360-degree coverage of the targets it is tracking, Anderson said. But in the 90-degree sector that it does scan, it sees everything in that field, which is a big advantage over radar systems that sweep through the field.

Boeing, Raytheon and L-3 Communications built LSRS. Boeing made the mission control system, Raytheon built the radar components and L-3 handled the aircraft modifications.

Before the Navy started publicly acknowledging details of LSRS, the LSRS "Advanced Sensor Technology Team" won a Department of Defense award for "innovative acquisition management techniques." The team of Anderson; Bradley Mudd, the Navy's chief of contracting; Boeing's Robert Colvert; and Fred E. Ellis of Raytheon received the Defense Acquisition Executive Certificate of Achievement on Oct. 4, 2006.

The LSRS team was lauded for making "exceptional contributions to improving life-cycle costs and/or the Department of Defense acquisition system" specifically by delivering the system components on time and within budget, testing for 2,800-plus hours without any safety or equipment mishaps and getting the system into the field ahead of schedule.

Anderson was cautious when asked about the unofficial rave reviews of LSRS's effectiveness in Iraq. He said he could not comment on the Woodward book. But he did say: "Obviously we've had some success." It isn't uncommon to make significant technology advances during a war, he said. "There's been leaps in technology made. In that vein, this has been one of those technological areas."

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