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Surveillance Data Fusion Defines Future Army Systems

Tuesday, December 02, 2010
By Robert K. Ackerman
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The U.S. Army’s Foliage Penetration Reconnaissance, Surveillance, Tracking and Engagement Radar (FORESTER) program aims to develop a low-frequency radar to track dismounted personnel under foliage. Army researchers are working to develop more versatile sensors to support increasingly diverse threat challenges.

The collection of information increasingly is defined by how it is processed.

U.S. Army researchers are taking the extended view as they plan near- and long-term intelligence and surveillance systems. New sensor suites are being designed to serve future requirements involving advanced data fusion and new approaches to situational awareness.

The need for greater surveillance and reconnaissance data fusion comes from the urgency of threat detection and defense. Adversaries are resorting to more diverse means of attack, and Army platforms face more hazardous environments. Just as network-centric information movement is a key to battlespace operations, so too is the architectural connection between sensor output and its application by users.

Work being performed at the Intelligence and Information Warfare Directorate (I2WD) in the Army’s Communications-Electronics Research, Development and Engineering Center (CERDEC) straddles both the intelligence and the military realms. “We’re trying to make it so that we’re able to outsense, outknow, outthink, outwit and outdo the adversary,” declares Dr. John Kosinski, chief scientist at I2WD.

The I2WD’s programs comprise five areas: radar; signals intelligence; information network operations; electronic warfare air/ground survivability; and fusion. These five disciplines increasingly are finding common ground in their support to the warfighter. Bill Porter, I2WD chief engineer, notes that the directorate inserts many quick-reaction capabilities into the field in response to rapid requests.

A lot of the directorate’s radar work involves penetrating radars such as synthetic aperture radars (SARs), relates Jan Moren, I2WD deputy director. Researchers also are lowering the overall operating waves on non-penetrating radars, particularly those that provide ground moving target indication in the open, he says. Another goal is to be able to see moving individuals under triple- canopy jungle. 

Dan Kuderna is the chief of the radar and combat identification division. It comprises airborne and ground branches, both of which research radar, and a combat identification branch. He notes that researchers are turning more toward radar for battlefield imaging. His division is working on high-frequency systems that provide better resolution for SARs for imaging, along with ground moving target indicator (GMTI) radars for tracking people.

The SAR technology goal is to improve capabilities to the point where synthetic aperture images look more like photographs. “There is a natural inclination of everyone to try to see photographs or full-motion video whenever possible,” Kuderna points out. The advantages that radar offers include range, for example. Range is not a factor in radar resolution to the extent that it is in optical imaging systems, so radar offers a standoff capability. Similarly, SAR has an all-weather nature in that it is not affected by clouds or other atmospheric conditions.

Higher-frequency radars translate to smaller sensors, Kuderna adds. This is especially advantageous for mounting on airborne platforms, which have significant payload weight and size limitations. Many of his division’s programs are slated for unmanned aerial platforms, and every bit of weight savings adds to the aircraft’s persistence time.

GMTI efforts are aiming at personnel as well as vehicles. The goal is technology that would detect and track targets at standoff ranges. Where high frequencies provide resolution, low frequencies serve for foliage penetration.

The ability to detect and track dismounted personnel is in great demand, Kuderna says. His division is working with the Joint Improvised Explosive Device Defeat Organization (JIEDDO) and the Defense Advanced Research Projects Agency (DARPA) on the Foliage Penetration Reconnaissance, Surveillance, Tracking and Engagement Radar (FORESTER) program, which aims to develop a low-frequency radar to track dismounted personnel under foliage and other complex environments in which adversaries normally would be concealed.

Another joint program with DARPA and JIEDDO is the Vehicle and Dismount Exploitation Radar program, or VADER. It aims to accomplish the same goal as FORESTER but in an open environment. Both programs face similar challenges such as target discrimination, data identification and false-alarm rejection, Kuderna allows.

The Artemis program seeks to combine the SAR and GMTI foliage penetrating capabilities of FORESTER in a single sensor. Engineers are eying the Fire Scout as the objective platform, so the challenge is to combine two 500-pound sensors into a single sensor that weighs 250 pounds.

In higher frequencies, the STARLite radar already is in production for placement on the Army’s extended range multipurpose MQ-1C Sky Warrior unmanned aerial vehicle (UAV). Another radar under development for that UAV is Tracer, a low-frequency SAR foliage penetration radar that currently is undergoing engineering flight tests. Its next phase will involve flight on an unmanned platform, and NASA’s Ikhana Predator-B type UAV will serve that role.

Ground-based radars aim to protect ground forces against enemy fires. Radars already are detecting incoming artillery and mortar rounds aimed at friendly forces, and further developments are designed to track those rounds for rapid countermeasures against attackers. More precise detection and tracking also will allow some warning for troops in the immediate strike area. Kuderna offers that his division is working cooperatively with the counter rocket, artillery and mortar program to network with other sensors for interdicting incoming rounds.

 

A higher-frequency radar, STARLite is a ground moving target indicator synthetic aperture radar. It is being placed on the Army’s extended range multipurpose MQ-1C unmanned aerial vehicle.

In addition to counterfires, ground surveillance radars are evolving toward the goal of a single multimission radar. This ongoing effort capitalizes on advances in antenna and signal processing capabilities. One achievement has been the lightweight countermortar radar, a single system that can scan 360 degrees mechanically and electronically for air surveillance and counterfire support. Kuderna relates that his division is looking to advance that capability to absorb more functions simultaneously without sacrificing radar performance.

For combat identification, one way of ensuring blue force situational awareness for avoiding fratricide is by surveillance of friendly troops. Kuderna describes this as an extremely challenging emerging technology area, and he allows that the division is considering all types of technologies—whether radio frequency, optical, laser or combinations. The goal is to tie these technologies into any battlefield shooter to give that person positive situational awareness of both valid and questionable targets.

Kuderna points out that radars are capable of producing much more data than the Army is capable of handling. The division focuses less on hardware and more on exploiting the raw data from radars to generate a product for a commander.

The Army is just beginning to determine how to combine the exploitation capabilities of individual sensors into a more generic toolset. “We’re trying to capitalize on the commonality of the sensors and their data—whether it is protocols, formats, sensor types and modalities—for a more generic toolset that could be applied to multiple sensors,” Kuderna states.

Moren notes that the Army is the lead for tri-service rotary-wing aircraft survivability, and this will have ground applications as well. Radar-controlled, heat-seeking and laser-guided missiles all pose threats to helicopters. New technologies can intercept and locate radio frequency systems and often jam them, and researchers are developing newer technologies to use lasers to jam sensor heads. As these airborne countermeasure systems are perfected, researchers strive to configure them for use on the ground to protect road vehicles.

Achieving these goals is spurring engineers to take an entirely new approach to countermeasure architectures. Isidore Venetos, chief engineer, air/ground survivability division, I2WD, explains that today’s systems represent a “sensor-centric solution set.” The current suite of sensors and countermeasures is effective, especially when it comes to detecting radio frequency, ultraviolet and infrared energy. “The sensor-centric approach responds to what’s around the platform today,” he says.

Each sensor works well, but no cross-correlation among sensors occurs. Division researchers plan to remedy that. One ongoing effort involves trying to correlate various types of sensor data while it is on the sensor platform.

But division experts are looking beyond even that approach. Venetos describes a future architecture in which the data is pushed off—or onto—the platform so that it can be combined with other data to improve situational awareness. The key lies in where that data is pushed offboard to, he says. This entails whether the data is pushed onto another platform or onto the Distributed Common Ground System (DCGS), for example, as well as what benefits emerge. With this nontraditional use of sensors, aerial platforms involved in the fight might send their airborne sensor information to a DCGS to contribute to an advanced situational awareness picture.

“This type of architecture could potentially help us avoid threats such as RPGs [rocket-propelled grenades], small arms fire and MANPADS [man-portable air defense systems],” Venetos predicts. “These are all threats that you can avoid or take action against before rotary-wing aircraft enter an area where they can be harmed by those threats.”

Above all, the different data from the various platforms must be able to correlate among themselves to improve situational awareness. The long-term goal is to enable dynamic mission planning that avoids threats.

Being able to exploit offboard threat countermeasures would save weight and power usage aboard the platforms that are targets of these threats. This approach goes hand-in-hand with the offboard threat detection. “If you know those threats are there, maybe you can start utilizing offboard types of countermeasures to negate those threats,” Venetos adds.

Venetos says that his division will release a request for information (RFI) soon that will describe some of these areas of interest. In addition to radars, other technologies such as communications devices potentially could be a threat. This RFI is seeking a multispectral approach, he says, and this will have major implications on sensor design. Still to be determined are the benefits and trade-offs this offboard architecture will entail.

One interim option may be to incorporate new capabilities to existing sensor suites. Venetos suggests that a platform’s existing ultraviolet sensors might be joined by an acoustic capability and infrared sensors. Correlated data from all three could provide enhanced hostile fire indication. In addition to signal processing, the key may be the capability to achieve size and weight reductions and at relatively low cost.

For future systems, one significant area of research involves the consolidation of electronic warfare. Having a single integrated electronic warfare system that performs every function would be akin to the approach used in creating the Joint Tactical Radio System (JTRS), Kosinski says. He states that researchers have been hard at work trying to perfect the conceptual paradigm. But the nature of electronic warfare must dominate this planning, and one key element is that many electronic warfare tools are different because they have roles or constraints specific to their mission. “We must recognize that it’s a family of capabilities that is built from a common enabling technology set, but that there are going to be nuanced differences and applications,” he emphasizes.

Some niche areas also are the focus of I2WD research. These include radio-frequency-specific emitter identification based on signals intercepts, and noncooperative signal processing in terms of modulation recognition. This involves being able to intercept a signal and then optimally measure its characteristics so that forces can interact with it as needed.

“If there is RF [radio frequency traffic] out there, we need to know who it is, what it is, what it’s doing, whether it’s something we have to be concerned with as a threat, a friendly or a noncombatant,” Kosinski says.

One important non-technical item being studied is whether experts can determine a metric for the value of a specific piece of information. This could prove vital when determining which sensor is worth tapping for information. Timeliness, relevance, precision and reliability all are criteria that should be considered for establishing this value at the commander’s level, Kosinski says, adding that, “the field of information theory currently is undefined and just plain doesn’t exist.” Until fundamentals such as this exist, planners cannot develop systematic engineering and design principles.

A related effort involves research into abductive inference, which entails reasoning from evidence. This is a way of thinking that is different from deduction and induction, Kosinski says. Current military operations require this approach: sensors detect and generate data, people in the field observe events, and decision makers must follow the trail of evidence to make the right decisions.

The sensor data that is placed onto the network must have the characteristics necessary to be of value. Getting that down to a science where its value can be determined is very important, Kosinski declares.

WEB RESOURCES
CERDEC I2WD: www.cerdec.army.mil/directorates/i2wd.asp
FORESTER: www.darpa.mil/ipto/programs/forester/forester.asp
VADER: www.darpa.mil/ipto/Programs/vader/vader.asp