Clip on Night vision
CLIP-ONS—BAD IDEA FOR TIES, BUT A GREAT CONCEPT FOR NIGHT VISION.
In the ground combat arena, one of the first significant milestones in clip-on night vision occurred in the mid-1980s with the introduction of the AN/PVS-7 series (A and B) image intensification (I2) night vision goggles (NVG) to first supplement, and eventually replace, the earlier AN/PVS-5 series.
In addition to higher quality image tubes, the PVS-7s were re-engineered to present the I2 image from a single image tube to both eyes (the PVS-5s used two tubes). With the image tube being the most significant cost driver in the NVG system, halving the tube requirements allowed the acquisition and fielding of more NVGs. But from a clip-on perspective, the new PVS-7 designs were also significantly lighter (680 grams/1.5 pounds versus 850 grams/1.88 pounds for the PVS-5), allowing the possibility of either wearing the PVS-7 series on a head mounting harness or clipping it to the front of the combat helmet.
In December 1985, the government awarded multiyear production contracts to Litton (AN/PVS-7A) and a joint venture of ITT/Varo (AN/PVS-7B). Known as the “Omnibus” award, the contract set the stage for subsequent omnibus contract packages that covered the multiyear procurement of NVGs (both ground systems like the AN/PVS-7 series as well as air systems like the AN/AVS-6—AN/AVS-9 Aviator Night Vision System series) and associated I2 tubes. These awards, usually divided between multiple contractor teams, were made in 1990 (Omnibus II), 1992 (Omnibus III), 1996 (Omnibus IV), 1998 (Omnibus V) and 2002 (Omnibus VI)
Along the way, an AN/PVS-7D design evolved, together with the emergence of a smaller, lighter I2 night vision device. Designated AN/PVS-14, the new device was a monocular design weighing only 400 grams/0.88 pounds, making it far more comfortable to clip onto a combat helmet.
On September 15, 2005, the U.S. Army announced the contract awards for its Omnibus VII package for “enhanced thirdgeneration image intensifier ground night vision devices and spare image intensifier tubes.” The award was split between Northrop Grumman Systems Corp. and ITT Industries with each of the two contractors receiving the same total potential award of up to 370,486 AN/PVS-14 night vision monoculars and 34.300 AN/PVS-7 goggles, plus associated spare image tubes.
In parallel with the Omnibus night vision award process, U.S. combat helmets have also gone through an evolution of their own, as the lightweight Personal Armor System for Ground Troops (PASGT) helmet, first fielded in the early 1980s (the first PASGT combat experience was Grenada in 1983, shortly before Omnibus I) has recently given way to the wider fielding of the Army Combat Helmet (ACH), which the “Big Army” took from the special operations Modular Integrated Communications Helmet (MICH) component of the Special Operations Forces Personal Equipment Advanced Requirements (SPEAR) program. While the PASGT weighed 3.1 to 4.2 pounds, depending on helmet size, the ACH weight spectrum is 3 to 3.25 pounds.
As noted above, recent clip-on night vision activities have centered on the Omnibus VI and Omnibus VII contract package awards. The Omnibus VI contract, which was split 60 percent to ITT and 40 percent to Northrop Grumman Electro-Optical Systems, saw hardware deliveries begin in 3QFY03 with a major 2QFY05 milestone involving the completed qualification process for a single battery AN/ PVS-14 monocular design.
Army program descriptions characterize the current PVS-7D design as “the standard issue goggle supplied to the U.S. military and its allies. It features simple user controls and fully automated image tube protection. This system allows the user to have complete freedom of movement while maintaining equilibrium in a hands-free application. The AN/PVS7D also incorporates an infrared (IR) illuminator with a momentary and continuous- on switching function. IR operation and low-battery indicators are displayed within the user’s field of view. The AN/PVS- 7D comes complete with a lightweight, fully adjustable military head strap that allows for comfortable long-term use. A wide range of optional accessories includes high magnification lenses, compass, IR spot/flood lens and helmet-mounting bracket.”
The AN/PVS-14 is described as “a lightweight, multipurpose, monocular night vision device with similar key features found in the AN/PVS-7D single tube night vision goggles. The objective and eyepiece assemblies allow attachment of similar accessories. The head/ helmet mount adapter is exactly the same. Also available is a weapon mount adapter to allow the system to be mounted on the M16/ M4 Picatinny rail.”
The Omnibus VIII contract award covered a five-year period (2005 to 2009) with initial night vision hardware deliveries under the contract beginning in January 2006.
ENVG
Along with the hardware deliveries and subsystem upgrades (i.e., qualification of the single battery PVS-14), ground force combat planners have also been exploring emerging technologies. A classic example of this exploration can be seen in the Enhanced Night Vision Goggle (ENVG), a system that combines I2 with infrared capabilities in a single integrated monocular design.
The emerging ENVG is a helmet-mounted passive device for the individual soldier. It optically combines imagery from an image intensification tube and a long-wave infrared sensor into a single image. Man-sized target recognition requirements, given detection, include 80 percent probability at 150 meters and 50 percent probability at 300 meters.
Because of the added infrared capabilities, the ENVG will be heavier than current I2-only systems, with a maximum weight specified of 2 pounds, including batteries. The initial ENVG design involves an optical overlay of I2 and infrared images but program plans include upgrading the system to a digital package that will use image processing techniques to improve the clarity of the merged images.
On April 7, 2005, ITT Industries Night Vision announced that they had received the ENVG contract award from the U.S. Army Research, Development & Engineering Command Acquisition Center, Unique Missions Division.
As noted in the ITT announcement, “While I2 and IR technologies have allowed the U.S. military and its allies to own the night for years, both technologies have strengths and limitations. The ENVG combines the strengths of both technologies into one unit, allowing soldiers to complete their missions more effectively, even when confronted by low-light conditions or obscurants such as smoke and fog.”
ITT partnered with Raytheon for ENVG, with the latter company providing its infrared experience while ITT provides I2 and system integration expertise. Company representatives added that the initial ENVG units would be used by Program Executive Office Soldier (PEO Soldier) in “a rigorous qualification process to ensure they are ready to be fielded. The testing is expected to last through April 2006.”
PEO Soldier schedules reflect that this ENVG “developmental testing” will be followed by initial operational testing and evaluation (IOT&E) in 3QFY06 with materiel release in 4QFY06. Work on the digital fusion package is also planned during FY06-FY08, followed by digital ENVG system development and demonstration, which is currently planned for FY08-FY09.
At the same time that the clip-on ENVG activities were underway, special operations planners were conducting their own parallel exploration of night vision technologies, as evidenced by the October 10, 2005 announcement that “USSOCOM would conduct a night vision technology conference November 1-3, 2005.” The purpose of that conference was to assess the current state of the technology and evaluate technology protection measures.
Meanwhile, a wide range of contractors are offering a range of clip-on night vision options.
Insight Technology Incorporated, for example, has been offering a lightweight, compact Minimonocular, with Gen III I2 tube integrated into a 255-gram/0.56-pound package with optional flip-up helmet mount. Another example is ITL’s 355-gram/0.78- pound Mini Night Single Eye Acquisition System (Mini N/SEAS).
Other excellent I2 offerings are available from companies like Night Vision Equipment Company, B.E. Meyers & Co. Inc., and others.
One interesting new industry concept has been unveiled by a company called Exigence. Known as I-Vision, the program integrates a thermal imager into a Level IIIA multistrike ballistic helmet. The thermal image is presented to the wearer through a helmetmounted monocle. The monocle is positioned like a bifocal lens, so as not to interfere with normal viewing operations. As noted in program descriptions, the I-Vision design “opens up applications for use of thermal imaging that have not been practical or possible until now.”
Another new design, which recently made its first public appearance at the October 2005 Association of the U.S. Army is found in “Tacti-Net” a new situational awareness tactical ensemble already being fielded to selected small elements within the U.S. military. The system was developed by Inter-4, a wholly owned division of Sierra Nevada Corporation. One key element of the complete Tacti-Net ensemble is Tactisight, a high performance CMOS camera and LCD display system designed to clip onto the standard helmet night vision mount. “Here’s a standard NVG mount, right here,” said Ralph Osterhout, former chief executive officer of Inter-4. “I was the guy that came up with the original design for mounting the PVS-7, way back when. So I’m fairly familiar with the problems of helmet-mounting night vision equipment.” Osterhout was referring to a company called S-TRON, which he founded in the early 1980s. As a primary subcontractor to Litton on the AN/PVS-7A program, S-TRON helped design and build the bulk of the goggle housing for the Litton image tube.
Returning to Tactisight, Osterhout continued, “So this [eyepiece], you have X, Y and Z adjustments, it’s infinitely adjustable, and this also can fold up and lock out of your way.” In addition, the eyepiece is designed with a duplicate NVG mount on its front surface, allowing the warfighter to place Tactisight over one eye and an AN/PVS-14 monocular over the other. “So in pitch black I can look at a moving map to know exactly where I am,” Osterhout said, “while seeing in pitch black.”
Obviously, there are physical limits to the technologies that can be clipped onto the front of a combat helmet. And one military organization trying to define those limits is the U.S. Army Medical Research and Materiel Command’s (USAMRMC) U.S. Army Aeromedical Research Laboratory (USAARL).
Under the Injury Biodynamics subcategory of its Military Operational Medicine arena, USAARL participants are developing “Design Guidelines for Head-Supported Devices (HSD).” The underlying mission of the effort is that future HSDs will require design guidelines and health hazard assessment methods “to enhance soldier performance and provide protection from neck injury.”
According to program descriptions, “Biomedically based design guidelines and assessment methods for HSDs, such as protective helmets, weapon-sighting and communication systems, are being developed. The development process will use epidemiological studies, biomechanics, injury studies with human cadavers and mannequins, and advanced biofidelic neck models to develop and validate neck injury criteria. The health risk assessment method includes the neck injury prediction model and algorithms that produce a risk assessment code based on the predicted injury severity and the probability of occurrence. HSDs are critical components; however, they increase the amount of weight supported by the head and neck and may place soldiers at risk of degraded performance or neck injury. This project will provide guidelines and assessment methods for the development of safe and effective HSDs, including the Future Force Warrior (FFW) helmet design.”
In the meantime, clip-on night vision is a busy arena as fielding continues on Omnibus VII devices, testing begins on ENVG prototypes, and military planners keep a sharp eye out for new contractordeveloped systems and technologies.
ANOTHER KIND OF CLIP-ON
The Smartronix Night Vision Imaging System (NVIS) is a clip-on filter that uses optically enhanced plastic to provide both mechanical durability and flexibility. The NVIS was specifically designed for laptops being used in aircraft cockpits and for nighttime ground operations where operators may use night vision goggles. The NVIS filter removes unwanted light interference from the illuminated display that is being used in vehicles and aircraft as well as for the forward-deployed operator. Without the filters, light sources may cause a blooming effect when viewing the screens through NVGs or give away a covert position. The Smartronix designed clip-on solution allows an end user to have a NVG compatible display if needed. Specific to the laptops, the filter’s clip-on solution permits a quick and reliable night vision retrofit to any laptop LCD screen. The NVIS filter can be designed to fit virtually any display size and shape. Additionally, the specific design of the filter allows laptops to be closed during transportation or it can be secured to the outside of the laptop when not in use.
When warfighters wear NVGs for visually covert applications, use of a ground mobile filter allows for secure computer operation and gives them the ability to observe their environment while transmitting the valuable information needed to complete their missions from a covert state. Flying with NVGs during nighttime operations that require cockpit laptop use can interfere with a pilot’s ability to see. The NVIS aviation filters are suited for use on helicopters and fixed-wing aircraft, and keep the laptop display from interfering with NVIS equipment while keeping the display readable with the unaided eye.
The filter’s visible transmission is very low, which makes an LCD laptop display virtually undetectable at a distance, but still readable to the user. The optical properties of the NVIS filters are designed to comply with existing specifications and standards for NVG compatible lighting and displays (e.g. MIL-L-85762A and MIL-STD-3009). ♦