SITIS Archives - Topic Details
Program:  SBIR
Topic Num:  AF071-019 (AirForce)
Title:  Untethered Helmet-Mounted Display for Night Vision Goggle Training Systems
Research & Technical Areas:  Human Systems

  Objective:  Develop a tetherless, helmet-mounted display suitable for use as a night-vision goggle training device in flight simulators.
  Description:  Current helmet-mounted display (HMD) systems which present simulated night-vision goggle (NVG) imagery to users employ tethering cables carry the video signal to the head mounted display and employ relatively inefficient CRTs as the display medium. The cables reduce freedom of user movement, especially as users may need to move about the cockpit during training exercises. CRT displays’ size and mass create simulator helmet form and fit problems with respect to helmet system weight and center of mass. There is a need to replace the tethering video cables with a very high bandwidth wireless video transmission capability and to replace the CRT display with a display capability whose form and fit is equivalent to that of the actual NVG. The required bandwidth is estimated to be in the neighborhood of one giga-bit per second. A minimum solution of an NVG HMD system that can transmit and display at each eye a non-interlaced, 1280 by 1024 pixel image with 16 bits of intensity per pixel at a 60Hz update rate is required; a higher 2000 X 2000 pixel resolution is desired. The display system is restricted to a total helmet-mounted mass of 540 grams.

  PHASE I: Expected result is a system design and a proof-of-concept demonstration of wireless data transmission and display capable of handling the requirements of the minimal solution. The system design should also address such areas as durability, reliability, and ease of installation/maintenance.
  
  PHASE II: Expected result is a helmet-mountable, prototype system incorporating as much of the system design as possible while keeping an eye towards building a unit that will stand up to a feasibility evaluation. This system will be evaluated at the Air Force Research Laboratory's Warfighter Readiness Research Division for feasibility of use in a simulated night-vision goggle training system.

  DUAL USE COMMERCIALIZATION: Military application: Training systems requiring a high-resolution, untethered, head-mounted display can use this technology, especially those that require user movement, such as the Army’s Dismounted Soldier Simulator. Commercial application: Applications lie in entertainment/gaming areas and in education/training where continual access to high-resolution reference manuals will allow faster training in areas like aircraft maintenance

  References:  1. Kraemer, W. & Pray, R. (July, 2000). Remote Wireless High Resolution Display Systems. Presented at IMAGE 2000, Scottsdale, AZ. 2. Lewandowski, R.J., Haworth, L.A., Giralamo, H.J., Editors (2001). Helmet-and Head-Mounted Displays VI. Proceedings of SPIE Vol. 4361. 3. Tulis, R.W., Hopper, D.G., Morton, D.C., & Shashidhar, R.N. (2001). Cockpit Displays VIII: Displays for Defense Applications. Proceedings of SPIE Vol. 4362, pp. 1-25.

Keywords:  wireless, high-resolution, helmet-mounted display, night-vision goggle simulation

Additional Information, Corrections, References, etc:
Ref #1: This paper is available on the 2000 ITEC CD-ROM. Order it from ITEC, Ltd. - Papers
Ref #1: This paper is available on the 2000 ITEC CD-ROM. Order it from ITEC, Ltd. - Papers
Ref #2: Available online through SPIE Digital Library.
Ref #2: Available online through SPIE Digital Library.
Ref #3: Available online through SPIE Digital Library.
Ref #3: Available online through SPIE Digital Library.

Questions and Answers:
Q: 1. Is it a valid assumption that the simulated night-vision goggle imagery will be monochrome only?

2. Would it be permissible to locally tether the HMD unit to an intermediate body-mounted location (shoulder, belt, etc) in order to minimize the HMD unit size and weight, as long as no off-body tethering is used?

3. If on-body tethering is permitted, does the mass restriction of 540 grams apply to total on-body equipment weight, or only to helmet-mounted equipment weight?

4. Is video data compression permitted and what metrics will be used to determine resolution and image quality?

5. What is the maximum permitted latency as measured from the time the image is delivered by the source to the time it is displayed in the HMD?

6. Is the transmitted signal a single video stream, or does it include streaming video with sequential still image overlays?

7. If both streaming video and overlaid stills are used or preferred, is resolution mixing permitted (e.g. low resolution video with high resolution gauges/indicator overlays) to optimize bandwidth usage?

A: 1. Goggle imagery is monochrome green.

2. Intent is that the final system be helmet-mounted only, with no other 'wearable' components.

3. Mass restriction applies to the helmet-mounted components.

4. Data compression is optional. Targeted resolution is 130 cycles/mrad.

5. Latency between delivery from source and display on HMD must support a 60 Hz update rate.

6. The transmitted signal is a single video stream.

7. If a mixed resolution display solution is anticipated, be aware that, in operation, the goggle is focused at infinity and is used by the pilot almost exclusively for viewing the out-the-window scene. To check inside-the-cockpit gauges/indicators, the pilot looks 'under' the NVG mounting shell and views the gauges/indicators directly.
Q: Requirements seem to imply that a) every pixel is updated on every vertical scan (i.e. no interlacing), and that b) no video compression is performed on the source training video. Are these assumptions correct?
A: A. The display should be implemented with no interlacing.

B. Data compression is not a requirement.
Q: 1. Should we consider, building NVG HMD flight simulator, that real NVG will be used, or image from GRT (in our case microdisplay) will simulate NVG image and overlap it with cockpit display reticals, symbols etc.
2. Can we replace commonly used head tracker with eye tracker?
3. Should we describe in detail applied wireless system, or just include info about COTS designed by some company 1Gbit/second wireless communication system?
A: 1. We anticipate that your implementation will follow the general form, fit, and mass of the current night vision goggle. You may choose to use the 'shell' of a pair of goggles, or you may choose to construct your own housing. In either case, the expectation is that the HMD system will attach to the aviator's helmet as does the current night vision goggle. The actual HMD itself will be fed by the image generation system.

2. Unless your solution has a cogent reason to implement an eye tracker, the preference would to be to retain the current headtracking capability. We have found that in an operational training situation, eye trackers bring additional overhead in maintenance, calibration, individual fitting, etc.

3. Your SBIR proposal should be stand-alone; the wireless system proposed should be described in sufficient functional detail that the proposal reviewers can evaluate it without resorting to outside sources.
Q: Requirements seem to imply that a) every pixel is updated on every vertical scan (i.e. no interlacing), and that b) no video compression is performed on the source training video. Are these assumptions correct?
A: A. The display should be implemented with no interlacing.

B. Data compression is not a requirement.
Q: 1. Should we consider, building NVG HMD flight simulator, that real NVG will be used, or image from GRT (in our case microdisplay) will simulate NVG image and overlap it with cockpit display reticals, symbols etc.
2. Can we replace commonly used head tracker with eye tracker?
3. Should we describe in detail applied wireless system, or just include info about COTS designed by some company 1Gbit/second wireless communication system?
A: 1. We anticipate that your implementation will follow the general form, fit, and mass of the current night vision goggle. You may choose to use the 'shell' of a pair of goggles, or you may choose to construct your own housing. In either case, the expectation is that the HMD system will attach to the aviator's helmet as does the current night vision goggle. The actual HMD itself will be fed by the image generation system.

2. Unless your solution has a cogent reason to implement an eye tracker, the preference would to be to retain the current headtracking capability. We have found that in an operational training situation, eye trackers bring additional overhead in maintenance, calibration, individual fitting, etc.

3. Your SBIR proposal should be stand-alone; the wireless system proposed should be described in sufficient functional detail that the proposal reviewers can evaluate it without resorting to outside sources.
Q: 1. Is it a valid assumption that the simulated night-vision goggle imagery will be monochrome only?

2. Would it be permissible to locally tether the HMD unit to an intermediate body-mounted location (shoulder, belt, etc) in order to minimize the HMD unit size and weight, as long as no off-body tethering is used?

3. If on-body tethering is permitted, does the mass restriction of 540 grams apply to total on-body equipment weight, or only to helmet-mounted equipment weight?

4. Is video data compression permitted and what metrics will be used to determine resolution and image quality?

5. What is the maximum permitted latency as measured from the time the image is delivered by the source to the time it is displayed in the HMD?

6. Is the transmitted signal a single video stream, or does it include streaming video with sequential still image overlays?

7. If both streaming video and overlaid stills are used or preferred, is resolution mixing permitted (e.g. low resolution video with high resolution gauges/indicator overlays) to optimize bandwidth usage?

A: 1. Goggle imagery is monochrome green.

2. Intent is that the final system be helmet-mounted only, with no other 'wearable' components.

3. Mass restriction applies to the helmet-mounted components.

4. Data compression is optional. Targeted resolution is 130 cycles/mrad.

5. Latency between delivery from source and display on HMD must support a 60 Hz update rate.

6. The transmitted signal is a single video stream.

7. If a mixed resolution display solution is anticipated, be aware that, in operation, the goggle is focused at infinity and is used by the pilot almost exclusively for viewing the out-the-window scene. To check inside-the-cockpit gauges/indicators, the pilot looks 'under' the NVG mounting shell and views the gauges/indicators directly.

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