Technology International Incorporated 0f Virginia

Head-Mounted and Wrist-Mounted SOF Tactical Information Displays

Topic: SOCOM 01-006; December 03, 2001 through June 03, 2002

Contract: C- USZA22-02-P-0502 U.S. Special Operations Command/SOAL-K, 7701 Tampa Point Blvd., MACDILL AFB, FL  33521-523

TPOC, PEO-IIS & PMI Technical Advisor & SBIR Project Manager: Mr. David Widdoes

PI: Dr. Zeinab A. Sabri
Project Team: Dr. Golden G. Richard, III; Dr. Abdo A. Husseiny; Richard E. Jarka and Srivatsa Gundala


Zeinab A. Sabri, Golden G. Richard, III; Abdo A. Husseiny; and Richard E. Jarka (July 03, 2002). Head-Mounted and Wrist-Mounted SOF Tactical Information Displays. TII-VA Report #: TILA-02-SOCOM-07, Contract #: C- USZA22-02-P-0502, U.S. Special Operations Command.


The goal of this Small Business Innovative Research (SBIR) project is to enhance personal and/or team performance of the Special Operations Forces (SOF) through the effective use of Tactical Information Assistants. The approach is to seek innovative technology ideas, which offer significant added value to current practice and that can be embedded into SOF Tactical Information Displays (STIDs) to allow individual users or teams to receive video signals that provide them with application-specific graphical and alphanumerical information transmitted from a Portable Digital Assistant (PDA) or any SOF operator’s computer using wireless technology.

Aiming at the design, building and demonstration of a family of tactical/military displays for the war-fighter including: wireless wrist-mounted, head-mounted or helmet-mounted and 4" or 6" hand-held STIDs to provide deployed SOF personnel with hands free information, a set of design, construction and performance requirements were developed. Those requirements were used to establish criteria for evaluation of commercially available displays that may be adapted or modified to meet the SOF needs for mission success and for evaluation of the produced STIDs, which are basically low power “remote” displays, similar to computer monitors.

The STIDs have to be rugged, safe, reliable, inexpensive (throwaways), small, lightweight (portable/wearable) remote electronic displays that consume little power (=0.5W to maximum of 1W) and have high resolution (SVGA/XVGA, with 32k colors). The STIDs are powered by internal rechargeable batteries that last a minimum of 6 hours and may last up to 12 hours. An external DC input is used to run with an external power source and/or to charge the internal battery. The wrist-mounted and hand-held STIDs have adjustable luminance, from off (dark) to bright enough to be seen in bright sunlight. The head-mounted STIDs have 32º viewing angle and may take the form of eyeglasses and/or a helmet mounted display. In either configuration, the mounting of the display should not result in interference with any normal team/crew duties.

With the exception of the cost and power consumption, a few displays; whether commercially available-off-the-shelf (COTS) or under development for the commercial market, partially meet the STIDs criteria, but have been designed and built for specific systems and hence are loaded with hardware irrelevant to the functionality of the STIDs. For those display technologies to be adapted for the STIDs, they have to be stripped from excess components and trinkets, redesigned and rebuilt not only to reduce the cost, size and weight but also to simplify their architecture while maintaining the functionality of the human machine interface. Furthermore, repackaging may be necessary for ruggedness and reduction in cost and size, since commercial products are concerned with decorative appearance that appeals to the consumers and marketability often takes precedence over usability. Furthermore, ergonomics for devices designed and constructed for civilian use differ from the human factors that have to be implemented for the battlefield.

New display technologies such as organic light emitting diode (OLED) and electronic ink displays (EID) cost less in manufacturing and use material less expensive than that used in the more commonly available liquid crystal displays (LCD). OLED employs polymers or organic molecule substrates that can be made of agricultural products. EID employs paper substrates. OLED consumes much less power than LCD, while EID power requirements are a fraction of that required for OLED. Nevertheless, both OLED and EID technologies have yet to develop to the level of maturity and market penetration of the LCD technology. Although the EID technology seems to satisfy the STIDs criteria the most, its development seems to lag behind the OLED technology. Both technologies suffer from the drawback of having short useful life, although this might not be a major impediment for building throwaway displays like the STIDs.

Batteries that are standard for commercial displays cannot deliver the necessary juice for continuous operation during a typical mission without frequent replacement. All COTS batteries of reasonable weight (e.g., suitable for a wrist or head-mounted application) fall short of lasting the required 6 hours. In addition, long life is not the only factor to be considered in selecting rechargeable batteries; as important is the reliability and availability of the power source when needed. Batteries, being dependent in operation on chemical reactions, tend to have uncertain life expectancy and may fail to function when needed the most. That is, their availability when needed as a power source is rather low. Rechargeable batteries often deteriorate in performance and last fewer hours after repeated charges.

One solution to such shortcomings is to direct attention to batteries being used in space; some of which, such as nickel-cadmium batteries last over 10 years.  Batteries used in pacemakers produce less energy but are also extremely reliable. Nuclear (beta-emitters or radioisotope) batteries are possibly the best candidate for STIDs because of their high operation life, reliability and dependability. They use a mature technology that has been tested and improved over the years, and can be customized for every application. An evidence for the safety and dependability of the nuclear batteries is their use in pacemakers early on. Although space-grade and nuclear batteries are costly, the trade off in this case is the ability to use the batteries over and over in successive generations of displays.   Fuel cells are another promising alternative to traditional batteries, but the technology is still very immature.

Improvement on materials, development of new materials and use of polymers made it possible for some displays to survive exposure to temperature extremes in the range of -20º to +70º C for extended periods.  Although the state-of-the-art technology can produce LCD displays that survive and correctly operate after being submersed at depths of 2 atmospheres for 3 hours, parachuted from altitudes of up to 20,000 feet, transported by air at altitudes up to 40,000 feet, this will be at an added cost premium regardless of the display technology. Since environmental compliance is a constraint on the construction of the STIDs, means to further reduce the cost are necessary to implement in order to offset the increased costs of survivability.

We have constructed a Phase I prototype which illustrates the technical feasibility of wireless displays meeting the SBIR requirements.  The prototype is a handheld unit, constructed primarily from off-the-shelf components, incorporating a 6.3" Toshiba LCD display, wireless networking components, an on-board computer for handling decompression of the video stream from the source display, and onboard NiMh batteries.   A 4" Toshiba LCD was originally planned, but significant backorders (> 12 weeks) precluded our obtaining one in time for the end of Phase I.  On the software side, we have adapted VNC and Tight-VNC software to capture changes in the source display and handle compression/decompression of transmitted video.  Our prototype uses Bluetooth or 802.11b wireless networking and while we do not currently constrain transmission power to prevent detection beyond 50 feet, modifications to our software can be made to achieve this in Phase II.  Additionally, even when detectability is reduced, other threats to wireless communications are and will continue to be major issues of concern that affect acceptability of STIDs.  Our software can easily accommodate encryption of the video stream to further harden the wireless STIDs against tampering and eavesdropping. One positive deviation from the original SBIR specification is that we require no hardware to be attached to the computer providing the source display—it need only run a small software application.

The Phase I prototype is a proof of concept, and several enhancements will be necessary to move the STID designs forward in Phase II.  We have created baseline Phase II designs for wrist-mounted, handheld, and head-mounted wireless displays which address further reductions in size, improved refresh rates, alternate wireless networking technologies, and better power management.   Better refresh rates will be gained primarily by incorporating a more powerful on-board computer and by continuing to enhance our software.  Surprisingly, we do not believe our designs are bandwidth starved—additional wireless networking bandwidth will offer only incremental improvements in refresh rate.  For Phase II, the wireless transmitter will be packaged into a small box to be attached to an LCD or OLED display element.  We will strive to separate the wireless networking and software issues from the choice of display elements to the highest degree possible, allowing a number of display types to be tested easily.  For example, since at least two displays of each type (wrist-mounted, head-mounted, etc.) are required in Phase II, one LCD and one OLED display of each type might be constructed.     This separation of networking issues and display technology has the added advantage of allowing our designs to rapidly embrace emerging display technologies.  As for the Phase I prototype, only a wireless networking interface is needed on the source computer—no hardware is required to be attached to the source.  Extensive user acceptance testing will be conducted in Phase II to demonstrate environmental compliance and successful performance of desired functions.  Feedback from these tests will be used to improve the STID designs.