Sensor Payloads for Manned and Unmanned Vehicles

Electro-optical sensor payloads are giving today's armored combat vehicles, trucks, and unmanned ground vehicles (UGVs) enhanced capability to enable users to find and disarm explosives, survey rugged terrain, and uncover enemy positions from safe distances.

By JR Wilson, freelance Aerospace and Defense journalist / Military & Aerospace Electronics


- Interview with Tara Martin, Business Development Director at UTC Aerospace Systems,
  Force Protection

Sensors have become the invaluable eyes and ears of warfighters in combat, ranging from space-based systems to manned aircraft, shipboard and ground-based. The latter have been the most difficult and the most immediately valuable to warfighters, who are relying on the rapid evolutions in technology to make them better meet size, weight and power (SWaP) requirements, while also significantly improving available imagery and situational awareness.

Electro-optical (E/O) sensors, at the lead of those best suited for on-the-move field applications, come in two basic forms: passive, which sense energy emitted by or reflected off a target, and active, which possess their own light source, typically used to illuminate an object or detect reflections. In both cases, E/O sensors convert light or a change in light into an electronic signal, enabling detection of flashes of light (such as a gun muzzle), interruptions caused by moving objects or the distance, absence or presence of an object in the sensor's field of view (FOV).

The iRobot back-packable small unmanned ground vehicle can accommodate a variety of electro-optical sensor payloads.

By using relatively short wavelengths of infrared and visible light, active E/O systems significantly exceed the angular resolution by as much as 20,000 times) and range precision of standard radars. Another advantage over passive E/O is being able to control illumination in environments where the target may not be emitting.

"The number-one thing we're seeing is a move toward multiband systems-two or three bands, sometimes merging that imagery rather than switching between them," says Tara Martin, business development director at UTC Aerospace Systems (nee Sensors Unlimited), in Princeton, N.J. "Another requirement we're seeing a lot more is laser-spotting and decoding to deal with fratricide. The time to lock onto and engage the target while also reducing fratricide is big, going from just trusting a bore sight to seeing a laser designator, for example.

"One of the biggest changes [since 9/11] has been increased sensitivity for low-light imaging and the increase in dynamic range, especially in urban conditions where you might want to see into a dark shadowed area or around bright light sources," Martin continues. "That has been one push for using SWIR [short-wave infrared], because, in addition to the immediate problem, the more NVGs are exposed to light, the more they degrade and the sooner they have to be replaced."

Rapid advances in computing and related technologies have led to increasingly sensitive and useful E/O sensors, while the past decade-plus of land combat in Southwest Asia has generated increased demand from warfighters. Both soldiers and Marines on the ground also want systems with significant improvements in SWaP, while the Pentagon adds to that lower cost (SWaP-C).

"Millimeter wave infrared [MMWIR] coming out of some of the national labs is overwhelming. The distances and the precision of the image, even in early morning low light, has changed how we work on some models," notes Michael Helfrich, founder and CEO of Blueforce Development Corp. in Salem, Mass.

"I see that for offensive and defensive applications. From a defensive perspective, it's a great app for integrated base defense, but also for interdiction missions offensively. SWIR [shortwave infrared] is pretty good for close in and a short distance out, but nowhere near MMWIR, which is really good for mass expanses and looking out far, even in extremely low light."

With ever-tightening budgets, the military has less money for cutting-edge research, which places a greater reliance on commercial off-the-shelf (COTS) components. But in a global market economy, COTS is not subject to U.S. trade restrictions on technology, such as ITAR (International Traffic in Arms Regulations). That makes many of the newest technologies available to potential adversaries at roughly the same time they reach U.S. military and contractor labs.

A report on "The Global Military E/O-IR Market 2014-2024" released by Strategic Defence Intelligence predicts that market to reach $7.3 billion by the end of 2014, rising to $10 billion by 2024.

DARPA's Adaptable Sensor System (ADAPT) program aims to transform how unattended sensors are developed for the military by using an original design manufacturer process similar to that of the commercial smartphone industry.


Army and Marines

There are differences between the Army and Marine Corps as well as the U.S. Special Operations Command (SOCOM) regarding funding and fielding of cutting-edge sensor technologies. But there also can be user resistance without proof something new also is significantly better.

"Once somebody has a capability, they never want it taken away. So if someone has an E/O long-wave sensor, they won't allow you to take it away unless you replace it with something better-and something smaller, no more costly and with higher capability. So we are constantly being driving to make that happen, such as smartly integrating sensors without driving up SWaP while still adding capability. But in the current government budget climate, most of what you hear is cheaper," Martin notes.

"The Marines are more willing to take a risk on new technology, while the Army is more comfortable with technologies that already have been vetted. Unfortunately, the Marines don't have the volume or budget to do their own sensors, so they usually end up adding on to an Army buy. SOCOM is willing to take an 80 or 90 percent solution to have the latest/greatest technology out there for their covert missions. But while they are capable of making the most use of the best technology, SOCOM doesn't have a lot of development funding-and still have bigger ideas than budgets."

In the 1980s and 1990s, with the introduction of then-high-tech night vision goggles (NVGs), the U.S. Army and Marine Corps legitimately could claim to "own the night." But by the turn of the century, technology proliferation meant only those with the latest technology improvements held any edge in low-light operations.

"The U.S. military has long prided itself on owning the night, but that changed as everyone got NVGs and cheap cell phones to detect illuminators. It is very important to have an asymmetrical advantage, but I think there will be a lot of sharing of the night in the future," Martin says. "The blending of multiple image bands is the main way to achieve that goal-and doing so in smaller SWaP packages will be a big driver in systems going forward. In the next five to ten years, I would say every system will become a blended system of multiple sensors.

"The days of having a long-wave or NVG, low-light level-only system will end. As soon as you turn on an NVG illuminator, you might as well be turning on a flashlight because almost everyone has the ability to see those now. So industry will be doing packages that are smaller, lighter, cheaper than today, but also more advanced and multi-band for better recognition, ID and detection capability operating across a much wider range of lighting and environmental conditions, while also having improved SWaP."

The iRobot 510 small unmanned ground vehicle uses electro-optical sensor payloads to detect, locate, and disarm hidden improvised explosive devices (IEDs) and other threats.

Sensor fusion, in this case, applies to individual systems for manned and unmanned ground vehicles, carried by individual warfighters or in fixed systems set up across the battlespace-as well as bringing the data collected by those systems together. But that, too, is an area of great international interest, as demonstrated by the Manpack Recce System (Lightweight Surveillance Package) being developed by Thales Defense and Security Systems in Germany.

"Infantry, airborne, and special forces, as well as border guards, may still have to deploy their assets on foot over substantial distances or need to use very small vehicles (quads, snowmobiles etc.) for transport. The very same users do, however, more and more require sophisticated surveillance systems as part of their mission to enable various operations as well as protecting borders or the forces themselves," according to Thales Group officials.

"The MRS as an integrated, modular and scalable solution where Ground Surveillance Radars [GSRs], E/O Systems, UGS and other sensors are integrated via a one-workstation control system. All sensors/components are man-pack-divided into one or two man-packs each-and self-sustaining, including positioning/alignment, power supply by batteries, and communication means."

The Thales brochure on its MUSEC2 control system says it can integrate 16 radars and 16 E/O sensors, with "display and superposition of radar, UGS, E/O and other sensor data, [with] full control of sensors" and the ability to cue cameras to those sensors. Warrior-carried MRS sensors are rated with detection ranges as much as 5 miles, light vehicle-mounted as much as 7 miles and larger vehicle-mounted as much as nearly 10 miles.

In the U.S., the Vehicle-Mounted Surveillance System from STARA Technologies Inc. in Gilbert, Ariz., offers a mast-based multi-sensor payload that can be customized to the operational and sensor needs of different users, including E/O-IR, GMTI (Ground Moving Target Indicator) radar and COP (Common Operational Picture).

"The VMSS is a multi-sensor, mast-mounted, persistent surveillance platform used to detect and identify hostile and/or foreign subjects. A flexible design allows for installation on a wide range of commercial and/or military vehicles, including pickup trucks, SUVs, tactical vehicles and more," STARA officials say.

The Blighter Surveillance Systems Blighter Scout with a lightweight e-scan radar and camera surveillance system designed for rapid deployment in border security hot spots and other similar security applications.

"[An] optional on-board operator workstation provides full system control in the field, incorporating a moving map display and automated tools (slew to cue, alarm zones and recording/playback) to assist with the prioritization of threats in congested environments. Each VMSS can operate independently or wirelessly network with other assets to create a highly flexible mobile surveillance network."

Meanwhile, Raytheon Vision Systems in Goleta, Calif., is working on the next generation of E/O-IR detectors with the development of advanced discriminating focal plane array (FPA) technologies in the 33-to-5-micron mid-wavelength infrared (MWIR) and the 8-to-12-micron long-wavelength infrared (LWIR) spectral regions by using a variety of semiconductor materials and FPA architectures.

"These include advanced III-V1 semiconductor strained-layer-superlattice (SLS) FPAs, II-VI2 semiconductor mercury cadmium telluride (HgCdTe) dual-band FPAs and uncooled bolometer FPAs using micro-electromechanical systems (MEMS). Each of these FPA technologies address different mission requirements and are being developed to not only increase sensor capability and performance, but also to provide improved manufacturability and reduce costs," Raytheon officials reported in the January 2014 issue of the company's Technology Today magazine.

"MWIR FPAs with higher operating temperatures are advantageous for reducing the SWaP of cooled systems. For this reason, high operating temperature FPAs are being developed based on molecular beam epitaxy-grown indium arsenide/gallium antimonide (InAs/GaSb) SLS bandgap-engineered barrier device structures. The goal is to develop materials that have the producibility advantage of traditional III-V indium antimonide technology, but the operating temperature advantage of HgCdTe... Together, these factors offer the promise of improved performance, higher yield, and reduced cost for FPAs fabricated on SLS material."

SELEX Galileo's Gyrocam 15-inch Triple Sensor (15TS) systems on an International MaxxPro Mine Resistant Ambush Protected (MRAP) vehicles, used by the Italian Army in coalition operations. The Gyrocam 15TS can be mast-mounted on virtually any land vehicle for remote surveillance needs.

U.S. military commanders and warfighters in the field, having seen the advances in E/O-IR sensors in recent years, are asking for more-much more.

"Definitely greater range, more precision at distance, low light capability and, as we develop the needed technologies, the ability to leverage non-human analytics, virtual trip wires, trigger boxes, etc.," says Blueforce's Helfrich. "Warfighters are being asked to monitor more and more ground and air machines, so automation and analytics are in high demand. So is the ability to correlate a ground hit with imagery, so you can escalate the right information."

At the Special Operations Forces Exhibition & Conference in Amman, Jordan, on 8 May 2014, Aselsan A.S. in Ankara, Turkey, an affiliated company of the Turkish Armed Forces Foundation, announced its Middle East joint venture with the King Abdullah Design and Development Bureau (KADDB) would enable it to strengthen its ties with the Jordanian Armed Forces. That will involve ASELSAN's border surveillance system, employing the Advanced Capability Aselsan Radar (ACAR) GSR and E/O Units (cooled thermal imagers, day TV cameras, laser rangefinder) as primary sensors.

"These systems are integrated with ASELSAN software, while the voice and data can be transmitted through its range of software-defined radios. Options include the integration of various other communication and sensor subsystems," the company says. "ASELSAN proposes adaptable and modular system solutions that can be tailored according to emerging threats, mission requirements and operational scenarios following a detailed analysis of the user requirements."

A 2014 report by the National Research Council Committee on Review of Advancements in Active E/O Systems to Avoid Technological Surprise Adverse to U.S. National Security-"Laser Radar: Progress and Opportunities in Active Electro-Optical Sensing"-reported one potential use for active E/O would be creating 3D imaging for greater situational awareness for unmanned ground vehicles.

"Active E/O sensing is poised to significantly alter the balance in commercial, military and intelligence operations, as radar has done over the past seven decades. The close analogy between conventional radar and active E/O sensing can serve as a guide to the trajectory of development for active E/O sensing," the report says. "Many of the techniques developed for radar have analogs in active E/O sensing, such as advanced waveforms and synthetic aperture imaging, and are gradually being implemented in active E/O sensing. Our knowledge of the diverse applications of radar technology has enabled a more diverse set of active E/O sensing modes in a relatively short time frame.

The Israeli ISR patrol vehicle, the Granit, is equipped with advanced radar, sensors and communication systems

"The United States leads in the development of high-performance active E/O systems in the military arena. However, significant E/O technologies are now being developed globally. For example, most commercial mapping and surveying systems are produced outside the United States-and all the DARPA Grand Challenge (2004-2005) autonomous vehicles used systems manufactured by the German company SICK because of their low cost and availability. In the literature, Europe has demonstrated a strong capability in a variety of military active E/O sensors. Many foreign-based component laser and detector technologies are more advanced than their U.S. counterparts for application in commercial and high-end active E/O sensors."

Noting recent advances in laser illuminators, sensitive broadband detectors, and rapid data processing are combining to enable active E/O sensing "to bring revolutionary advances in areas such as mapping, targeting, autonomous robotics, environmental monitoring, weather prediction and intelligence gathering," the committee drew what it termed an "overarching conclusion."

"Active electro-optical sensing is a rapidly emerging technology with many applications across intelligence, military, scientific, and commercial domains. It has the potential to alter the balance in many of these areas. Interest in developing and applying active E/O sensing has consequently risen in other nations, putting U.S. leadership at risk, to the degree that in some instances the United States no longer leads."

Aimpoint's FCS12 fire control system has been placed in active service with the Swedish Army on the 84mm CARL GUSTAV M3 multi-purpose weapon system built by Saab Dynamics.

Blueforce's Helfrich says he agrees, but still sees a lot of significant advances in U.S. technology making its way from the lab to the battlespace-including COTS, but used in ways few other nations can match.

"I've watched multiple generations in sensors and I'm seeing a greater correlation of sensors and imagery assets with different ranges. They have tightly coupled off-the-shelf capabilities in UGS-smaller form factors, smaller optics, smaller gateways to move information, more freedom of choice in how they move data and in what format, especially standardization rather than proprietary," he says. "So we're seeing things being made much smaller, with more variety in how we move information and much more interoperability. The early stuff was Iridium and other SATCOM, ground sensors using traditional RF spectrum, but now there is a lot more leverage of terrestrial broadband, LTE, 4G, etc. And the smaller the company building UGS, the more the use of open standards."

As to the future: "Certainly we will have to continue to miniaturize. In unattended apps, there will have to be greater efficiencies in power consumption," says Blueforce's Helfrich. "The encoders still aren't giving us the compression we need without loss in image resolution. If I can reduce the stream size but keep image quality, it will have a positive impact on communications requirements.

"There needs to be additional consideration for the breadth and types of sensors that might cause cameras to take photos or open communications, especially signal detectors picking up devices that shouldn't be there. So service-oriented architectures that can be integrated with E/O sensors-systems of systems."

DARPA is using the QinetiQ TALON IV tracked UGV to carry a variety of sensor payloads as part of the Autonomous Mine Detection System (AMDS) to detect, mark, and neutralize explosive hazards.

UTC Aerospace Systems' Martin also echoes the concerns many others have voiced about technology restrictions originally created to protect the U.S. edge now becoming the undoing of that advantage in combat.

"I think we'll continue to see [U.S.] companies working together to come up with solutions to build these systems. We generally have a very strong industrial/technology base here, but one of the big issues may be that ITAR, rather than protecting U.S. technology, may simply encourage others to develop their own. And while that might not be a significant investment, compared to U.S. budgets, it still would create a protected market we really can't enter.

"We see a lot of that with SWIR, being as 'protected' as it is now on the munitions list, which creates quite a business challenge for commercial applications. That means you have to rely entirely on military funding to move technology forward. So if we want technology that is better than what is available elsewhere, a lot of funding needs to be put into it to keep that from happening. And that is getting tougher these days."

Tara Martin, Business Development Director at UTC Aerospace Systems / Sensors Unlimited Products in Princeton, N.J.