Looking Ahead with FLIR

Written by Peter A. Buxbaum

Although FLIR has been around for decades, having been first developed in the 1970s, efforts to improve and innovate are still robust, and the military continues to develop new ways to use it. This has been especially true since the beginning of U.S. operations in Afghanistan and Iraq.

FLIRs are infrared sensors that detect slight variations in heat and transform those readings into a visual picture in much the same way a digital camera detects and records light patterns. But since FLIR is not light dependent, it has an obvious application for night vision. It is also not impeded by inclement weather or the smoke, fire, dirt and dust of a battlefield.

Perhaps the most common and significant deployment of FLIR technology in Southwest Asia and Afghanistan has been on vehicles, where it has become a vital tool in the battle against IEDs. But the technology has also been incorporated on airborne platforms and integrated with other sensors.

In addition, while FLIRs have traditionally been too expensive to be incorporated into a man-wearable apparatus, that situation is changing. New research is allowing less expensive, although less sensitive, types of FLIRs to be developed.

TARGET ACQUISITION

Future FLIR applications will see an increased emphasis on target acquisition and integration with larger mission management systems, experts predict.

“Heat is a very difficult feature to hide,” said Don Reago, principal deputy for technology and countermine systems at the Night Vision and Electronic Sensors Directorate of the Army RDECOM Communications- Electronics Research Development and Engineering Center (CERDEC). “Everything emits heat, and thermal differences can be detected. Over the years, sensors have become so sensitive they can detect differences in thousandths of a degree.”

Prior to the innovations deployed in Southwest Asia, FLIR systems were generally used to protect large fixed installations. Infrared cameras were mounted on towers or installed on aerostats, where they can scan the approaches to a facility and detect the presence of threats.

“The typical deployment was on a mast or a tower with its base inside the perimeter but high enough to provide 360-degree surveillance around the facility,” said David Strong, government division marketing vice president at FLIR Technologies. “This kind of sensor can detect and identify threats at fairly long distances.”

There are now multiple types of FLIR systems available for use from a wide variety of different manufacturers, Reago noted. “These break down into two categories: high-performance FLIRs that employ cooling to improve the sensitivity of detectors, and newer, uncooled products that are less sensitive but also much less expensive.”

“With the wars in Iraq and Afghanistan, there has been a huge focus on IED detection,” said John Spadafore, vice president and division manager of CACI’s Integrated Sensor Systems Division, which supports the Army’s FLIR product manager. “Because FLIRs operate by detecting changes in temperature, they have proved valuable in detecting IEDs that have been placed on the side of a road or even buried under a road.”

The metal in an IED emits a different heat signature than the dirt road that may be covering it. “That is why FLIRs have been integrated on ground vehicles to clear routes in Iraq,” said Spadafore.

Another FLIR application also directed toward force protection has been installed in UAVs in the zone of operations. The FLIRequipped UAV makes two or more passes over an area, and the data generated is run through change detection software, Spadafore explained, in order to locate IEDs and other threats.

“The airborne applications are driving the technology efforts more so than ground,” he said, “because with airborne you’re always dealing with size, weight and power, and especially in the case of UAVs, you often have very low payload capacities. With airborne applications, you are also looking to get better performance from a range standpoint.”

THIRD GENERATION

The Army is currently working on a third generation of FLIR, which combines sensors using two different infrared bands in order to obtain the best range and resolution under varying environmental conditions. The current generation FLIR deployed on tactical vehicles uses a long-wave IR sensor, which is best to penetrate battlefield obscurants but doesn’t perform that well at long distances.

“The performance of the IR sensors is analogous to how radios are deployed,” said Spadafore. “Higher frequencies are used to reduce the size of antennas, and lower frequencies are used to improve penetration. With the third-generation FLIRs, a longer wavelength is used for improved penetration, and a shorter one is used for heightened resolution. They are combined in single devices and have been done in such a way that costs do not go up.”

The longer-range capabilities of the shorter-wave IR sensors in the third-generation FLIR will enable warfighters based on Abrams tanks and Bradley fighting vehicles to use the technology for target identification.

“The Army demands a high level of confidence before engaging a target,” noted Reago. “The longer range improves that capability and improves the survivability of our own forces.”

Third-generation FLIR sensors are already being deployed on the Navy F/A 18 E/F Super Hornet strike fighters operating in the Afghanistan theater. Raytheon’s ASQ 228 sensor, which is being incorporated in the Super Hornet, combines a third-generation FLIR sensor with an electro-optical camera, a laser marker and a laser spot tracker.

“Missions are conducted at great ranges in Afghanistan,” said Jeff Ayers, a senior manager at Boeing’s aviation and aerospace business, which makes the Super Hornet. The front seater in the F/A 18 prepares an electronic map of his area of responsibility before flight, Ayers explained. The back seater operates the FLIR sensor. When the crew views an object of interest, the back seater is able to identify the potential target and make a precision designation with the laser marker.

“The marked object is then either self-targeted with a weapon or passed to a tactical air controller on the ground,” sad Ayers. “The FLIR is later used to assess battle damage after the fact and where appropriate images are stored to a solid state recorder.” The images are later used to verify the battle damage assessment.

On the other end of the spectrum of technological innovation, the Army is working to drive FLIR costs down with an eye toward the development of products that can be used by individual soldiers. “Cost is a major element in FLIRs,” said Reago. “Because they are fielded so widely within the Department of Defense, it is important to keep costs down.”

Traditional FLIRs are an expensive proposition. The elements must be cryogenically cooled to the temperature of liquid nitrogen: 70 degrees Kelvin or -200 degrees Celsius. “This requires an exotic cooler pump to be incorporated in the device,” said Spadafore. “Not only does this make them very expensive, but they also use a lot of power.”

The answer was to develop a class of uncooled FLIRs. These devices are cheaper and small enough to be incorporated into weapons sights, goggles and helmets. “This new class of infrared detectors does not need to be cooled, but they are also not as sensitive and their ranges are not as long” as their more sophisticated counterparts, said Reago. “But they are so much smaller, lighter and less expensive that they are now getting a trial by fire. We are able to provide them to the lowest echelons of soldiers.”

Research into new FLIR applications is also going toward the development of higher performance sensors capable of higher resolution, wider fields of view and longer ranges. Makers of FLIR sensors have taken a cue from digital camera manufacturers, which have managed to cram a great deal more capacity over the years into smaller packages.

“We are looking at FLIRs for a wide variety of applications,” said Reago, “from enhancing the capabilities of UAVs to aiding in helicopter pilotage.”

PERSISTENT SURVEILLANCE

Increasing sensor performance suggests an application for persistent surveillance, which is currently being researched by FLIR Technologies. The idea is to use a FLIR as an “eye in the sky,” essentially a surveillance system mounted on a UAV loitering over a specific area.

“We want to be able to view large areas at very high resolution because it is often difficult to know where a threat might emerge,” said Strong. “We are working on enabling a sensor to see at extreme distances and at very high resolutions.”

Strong envisions an ultimate system working almost like a surveillance camera, transmitting images to the ground and also recording them. “If something happens, it is possible to go back to tape and see it,” he said. “This could also aid in investigations of who was responsible for specific incidents and provide intelligence that will aid in a response to a future incident.”

What is coming down the road for the Army is the incorporation of FLIRs into a system that will enable target designation. “A big piece of the Army mission is designating targets with the use of FLIRs that are handheld or portable with teams,” said Spadafore. “The FLIRs will be used to designate targets, which are then painted with lasers for air support to hit.”

The ASQ 228 sensor aboard the Super Hornet already is integrated with a target designation mechanism. The next step for that application is to integrate the sensor with larger mission management systems. “FLIR imagery will also be incorporated into what we call the distributed targeting system, in which we coordinate that imagery with geospatial maps in order to provide more precise coordinates for more precise weapons,” said Ayers.

In addition, efforts are still under way to reduce the overall costs of FLIRs without sacrificing performance, as is the case with the uncooled devices. “Current FLIRs use exotic and expensive materials,” said Spadafore. “There is now a big push to invent ways to use more traditional materials in FLIRs that are cheaper and easier to work and which provide similar performance.

“That research is coming along,” Spadafore said, adding that while there has not been a big breakthrough, he expects those efforts to eventually bear fruit. ♦

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