Specialized Applications and Future Systems #2 Overview: Military Optics The adv

Question

Specialized Applications and Future Systems #2

Overview: Military Optics

The advantages of most night vision and thermal imaging systems are obvious. Some special applications of visual augmentation systems can provide increased operational capabilities beyond just seeing what others cannot. There are a large number of important special applications for visual augmentation systems. There is only enough time to survey a few of them during this course, but it is important to remember that with any new technology there are new opportunities to exploit them. Sometimes old concepts of operations need to be replaced with entirely new methods. Sometimes, minor changes to old methods reveal an entirely new niche for the technology. While reading about some of these technologies, try to keep in mind how they might benefit some of the problems experienced in the field. Many of these technologies are still highly specialized and are not yet fielded, however, it is frequently a clear operational need and a sponsor willing to learn enough about the technology and ask for the capability that makes them a reality.

.Try to take away some of the basic concepts of the history of optics and the scientific method. The rise of these two disciplines closely parallels the rise of civilization and their success has helped bring about the modern age.

Understanding some of the basics of optics can greatly aid in evaluating systems. Magnification, resolution, the electromagnetic spectrum, refraction, reflection, and the inverse square law are critical to understanding the function of visual augmentation systems.

Similarly, the human eye and perception molds the way we ultimately make sense of the information presented to us. Variations in how we perceive the world can be very non-linear – that is, very small changes in a system such as lighting, contrast or brightness can sometimes make huge differences in the information that can be extracted from a scene.

Night vision and thermal technologies differ not only in the part of the electromagnetic spectrum they utilize, but whether they use reflected or emitted light to form an image. Understanding the strengths and weaknesses of each system and appropriateness of auxiliary systems such as illuminators and beacons is critical to proper selection.

Finally, there are a huge variety of special applications and that creative application of visual augmentation technology to a particular concept of operations can yield a highly effective solution. New technologies may mean that entirely new CONOPS are required to exploit them properly while a flexible outlook is maintained in order to avoid remaining tied to old ideas. Ultimately, it will be the users that directs the future of visual augmentation systems. Understanding these systems, being able to properly evaluate them, and the requirements to relay needs to industry are critical to the evolution of the technology.

Covert Imaging (SWIR, etc)

When a thermal imager is inappropriate for a particular role and/or supplementary illumination is required, sometimes an imager from another band should be considered. Imagers such as Short Wave Infra-red (SWIR) systems based on Indium Gallium Arsenide (InGaAs) technology, provide the ability to see illumination, beacons and dyes that are invisible to night vision or thermal systems. While the adoption of SWIR has been slow, it has been more widely utilized in recent years especially as the availability of laser illuminators, beacons and lenses for this band have become more readily available. It provides a powerful capability in a band that has not yet been widely compromised.

Range Gated Imaging

Range gated imaging uses a carefully timed pulse of light from a laser illumination system along with precision timing of the imager to see light being reflected from only a specific range from the camera. This allows the system to "see" through foreground clutter. While a promising technology the huge speed of light (300,000 km/s) requires very short exposure times on the imager and very short laser pulses. This means besides precision timing, the imaging system is generally starved for light and needs very high powered laser pulses and a very sensitive camera.

Multi-Spectral/Hyper-Spectral Imaging and Image Fusion

Multi and hyper spectral imaging consists of imaging a set of discreet wavelengths or a spread of wavelengths and sorting and displaying this information to obtain more detailed information about a subject. The appearance of different objects that have the same brightness across a wide wavelength band may have very different brightness in individual bands. Multispectral imaging usually consists of monitoring up to three discreet channels to approximate the spectral composition of an object. This method differs from hyperspectral imaging, in that hyperspectral imaging generally involves monitoring many more spectral bands. Image fusion usually means the combining of the image from disparate imaging systems into a single display. Common examples of sensor fusion systems combine visible and night vision or night vision and thermal.

Tagging Tracking and Locating (TTL)

The covert placement of beacons, dyes, or other distinguishing markings that are tuned to specific visual augmentation systems can provide a critical capability for tagging a target of interest. When a covert solution with a low probability of detection/low probability of intercept (LPI/LPD) is important and RF silence is critical, the use of an out of band optical solution is indicated. Even in cases where RF is feasible, it is often important to have greater localization than available from RF systems – identifying exactly which person or vehicle in close proximity can be difficult to differentiate. Optical systems can remove this confusion.

THE QUESTION:

obstacles to night vision

That are some of the biggest obstacles to digital night vision and other next generation technologies? You are encouraged to think big here - apply what you've been learning. No wrong answers here, just creative ones

Explanation / Answer

The Army is pushing night-vision technologies into the digital realm. Future night-vision goggles are being designed not just to see better at night but also to allow soldiers to share images of what they see with other soldiers who may be miles away.

Technologists agree that the goal is feasible, but contractors currently working on these next-generation goggles are encountering challenges in meeting the Army’s requirements for power, size and weight.

The technical difficulties may delay Army plans to award a production contract next year.

Soldiers currently use traditional night-vision technology, called image intensification. These goggles amplify non-visible particles of light to a level of brightness that the human eye can detect. They also employ infrared thermal sensors, which sense temperature differences. Warmer items appear brighter on a display.

The fusion of both technologies would result in night-vision goggles that merge the strengths of image intensification — a clear, sharp green-tinted picture — with the advantages of infrared — the ability to see practically under any environmental condition. Green is the color that the human eye sees most easily.

The combination of the two systems into a single optical device resulted in what the Army calls an “enhanced night vision goggle,” or ENVG.

The current ENVG, however, is analog, and does not pipe data into the soldier’s radio, as the Army wanted.

“We’re trying to transition to a digitized version,” Army Maj. Theophile Kang, assistant product manager for the ENVG program, tells National Defense. ”There’s a lot more things you can do with a digitized system that you can’t do with an analog system,” he says. In cities, for example, streetlights can overwhelm night vision goggles and wash out the image. But if the devices were digital, software could help the system adjust the image, Kang says.

The Army has awarded several contracts for the development of digital ENVGs. It plans to evaluate the designs in July to see how the technologies have matured from the previous test last year.

Soldiers will test the goggles in a variety of environments, including in urban training facilities and on woodland patrols.

“You have real soldiers giving you real feedback,” says Kang.

The largest provider of night-vision technology to the military, Roanoke, Va.-based ITT Night Vision, manufactures the ENVG for the Army. Engineers there are developing a digital version.

For the digital ENVG, the company has replaced the standard image intensifier tube with a new digital sensor, the MicroChannel Plate Complimentary Metal-Oxide Semiconductor, or MCP-CMOS. The microchannel plate sits inside a vacuum package between the photocathode and the electron-collecting semiconductor array.

“Rather than integrating the digital imaging outside of the vacuum, we just integrate it inside the vacuum,” says Rudy Benz, director of sensor development. He spoke at an Institute for Defense and Government Advancement night vision conference.

The digital sensor gives better low-light level performance compared to other technologies, says Don Morello, director of government marketing and domestic business development.

At the conference, Benz put up a slide comparing imagery taken with the new digital technology to a still captured by the company’s legacy PVS-14 monocular device. The images looked nearly identical.

But going digital does come at a price, as demonstrated by the cell phone and camera industries several years ago. Just as those initial products were larger, heavier and more power hungry than their analog counterparts, so, too, are digital night-vision goggles that fuse thermal and low-light capabilities electronically.

“The downside to fusion is the more number of pixels you deal with, the more power you need for processing the data from all those pixels. That starts to drive your power, and power can drive weight and size,” says Rajani Cuddapah, senior program manager of electronic solutions at BAE Systems, which is competing for the digital ENVG contract.

A leader in thermal capabilities, the company has leveraged existing low-light level visible technologies to develop its digital prototype, she says. In the upcoming evaluation, BAE Systems is hoping to show advances in size, weight and power, she adds.

Five of ITT’s digital ENVG prototypes were tested at Fort Benning, Ga., in late spring, and reports are filtering back to the company.

“The devices, in our opinion, still have some more work to be done specifically to reach Army’s very aggressive goal of less than two pounds,” says Morello. “It can be achieved with some work and some more user feedback and some more decisions from the Army.”

The Army believes that by 2014, the digital ENVG-D will be ready for production, says Kang.
The Army’s program executive officer for soldier equipment, Brig. Gen. Peter N. Fuller, says he is confident that contractors can overcome the technical difficulties. But he says he is not surprised by the troubles experienced by ENVG because the technology is such a huge leap from the current systems.

“It’s a black art” to make these new systems, Fuller says in an interview. ITT’s earlier manufacturing problems with ENVG tubes were attributed to the use of pure water from the local reservoir, which had more particulates. “When you’re building something that requires pure water, the particulates were a problem, they were organic matter such as pieces of leaves, things that we wouldn’t notice in drinking water,” says Fuller. “We figured out how to change the filters.”

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