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Sample records for head mounted display

  1. Maintenance Procedure Display: Head Mounted Display (HMD) Evaluations

    NASA Technical Reports Server (NTRS)

    Whitmore, Milrian; Litaker, Harry L., Jr.; Solem, Jody A.; Holden, Kritina L.; Hoffman, Ronald R.

    2007-01-01

    A viewgraph presentation describing maintenance procedures for head mounted displays is shown. The topics include: 1) Study Goals; 2) Near Eye Displays (HMDs); 3) Design; 4) Phase I-Evaluation Methods; 5) Phase 1 Results; 6) Improved HMD Mounting; 7) Phase 2 -Evaluation Methods; 8) Phase 2 Preliminary Results; and 9) Next Steps.

  2. Next-generation head-mounted display

    NASA Astrophysics Data System (ADS)

    McGuire, James P., Jr.

    2010-02-01

    Head Mounted Displays (HMDs) have been utilized by the military for various applications since the 1980's. In the 1990's, this technology migrated to the consumer market. Most of these early systems suffered the major drawback that they were "look-at" versus "see through" systems, which prevented the user from seeing their environment. This reduced the utility of the devices and could potentially lead to safety issues. This presentation discusses the optical design of a novel see-through High Definition display device with a 40 degree field of view.

  3. Multifocal planes head-mounted displays.

    PubMed

    Rolland, J P; Krueger, M W; Goon, A

    2000-07-01

    Stereoscopic head-mounted displays (HMD's) provide an effective capability to create dynamic virtual environments. For a user of such environments, virtual objects would be displayed ideally at the appropriate distances, and natural concordant accommodation and convergence would be provided. Under such image display conditions, the user perceives these objects as if they were objects in a real environment. Current HMD technology requires convergent eye movements. However, it is currently limited by fixed visual accommodation, which is inconsistent with real-world vision. A prototype multiplanar volumetric projection display based on a stack of laminated planes was built for medical visualization as discussed in a paper presented at a 1999 Advanced Research Projects Agency workshop (Sullivan, Advanced Research Projects Agency, Arlington, Va., 1999). We show how such technology can be engineered to create a set of virtual planes appropriately configured in visual space to suppress conflicts of convergence and accommodation in HMD's. Although some scanning mechanism could be employed to create a set of desirable planes from a two-dimensional conventional display, multiplanar technology accomplishes such function with no moving parts. Based on optical principles and human vision, we present a comprehensive investigation of the engineering specification of multiplanar technology for integration in HMD's. Using selected human visual acuity and stereoacuity criteria, we show that the display requires at most 27 equally spaced planes, which is within the capability of current research and development display devices, located within a maximal 26-mm-wide stack. We further show that the necessary in-plane resolution is of the order of 5 microm.

  4. Head-Mounted and Head-Up Display Glossary

    NASA Technical Reports Server (NTRS)

    Newman, Richard L.; Allen, J. Edwin W. (Technical Monitor)

    1997-01-01

    One of the problems in head-up and helmet-mounted display (HMD) literature has been a lack of standardization of words and abbreviations. Several different words have been used for the same concept; for example, flight path angle, flight path marker, velocity vector, and total velocity vector all refer to the same thing. In other cases, the same term has been used with two different meanings, such as binocular field-of-view which means the field-of-view visible to both left and right eyes according to some or the field-of-view visible to either the left or right eye or both according to others. Many of the terms used in HMD studies have not been well-defined. We need to have a common language to ensure that system descriptions are communicated. As an example, the term 'stabilized' has been widely used with two meanings. 'Roll-stabilized' has been used to mean a symbol which rotates to indicate the roll or bank of the aircraft. 'World-stabilized' and 'head-stabilized' have both been used to indicate symbols which move to remain fixed with respect to external objects. HMDs present unique symbology problems not found in HUDs. Foremost among these is the issue of maintaining spatial orientation of the symbols. All previous flight displays, round dial instruments, HDDs, and HUDs have been fixed in the cockpit. With the HMD, the flight display can move through a large angle. The coordinates use in transforming from the real-world to the aircraft to the HMD have not been consistently defined. This glossary contains terms relating to optics and vision, displays, and flight information, weapons and aircraft systems. Some definitions, such as Navigation Display, have been added to clarify the definitions for Primary Flight Display and Primary Flight Reference. A list of HUD/HMD related abbreviations is also included.

  5. Camera Mount for a Head-Up Display

    NASA Technical Reports Server (NTRS)

    Geoge, Wayne; Barnes, Monica; Johnson, Larry; Shelton, Kevin

    2007-01-01

    A mounting mechanism was designed and built to satisfy requirements specific to a developmental head-up display (HUD) to be used by pilots in a Boeing 757 airplane. This development was necessitated by the fact that although such mounting mechanisms were commercially available for other airplanes, there were none for the 757. The mounting mechanism supports a miniature electronic camera that provides a forward view. The mechanism was designed to be integrated with the other HUD instrumentation and to position the camera so that what is presented to the pilot is the image acquired by the camera, overlaid with alphanumeric and/or graphical symbols, from a close approximation of the pilot s natural forward perspective. The mounting mechanism includes an L-shaped mounting arm that can be adjusted easily to the pilot s perspective, without prior experience. The mounting mechanism is lightweight and flexible and presents little hazard to the pilot.

  6. Exploring Virtual Worlds With Head-Mounted Displays

    NASA Astrophysics Data System (ADS)

    Chung, James C.; Harris, Mark R.; Brooks, Frederick P.; Fuchs, Henry; Kelley, Michael T.; Hughes, John W.; Ouh-Young, Ming; Cheung, Clement; Holloway, Richard L.; Pique, Michael

    1989-09-01

    For nearly a decade the University of North Carolina at Chapel Hill has been conducting research in the use of simple head-mounted displays in "real-world" applications. Such units provide the user with non-holographic true three-dimensional information, since the kinetic depth effect, stereoscopy, and other visual cues combine to immerse the user in a "virtual world" which behaves like the real world in some respects. UNC's head-mounted display was built inexpensively from commercially available off-the-shelf components. Tracking of the the user's head position and orientation is performed by a Polhemus Navigation Sciences' 3SPACE* tracker. The host computer uses the tracking information to generate updated images corresponding to the user's new left eye and right eye views. The images are broadcast to two liquid crystal television screens (220x320 pixels) mounted on a horizontal shelf at the user's forehead. The user views these color screens through half-silvered mirrors, enabling the computer-generated image to be superimposed upon the user's real physical environment. The head-mounted display has been incorporated into existing molecular modeling and architectural applications being developed at UNC. In molecular structure studies, chemists are presented with a room-sized molecule with which they can interact in a manner more intuitive than that provided by conventional two-dimensional displays and dial boxes. Walking around and through the large molecule may provide quicker understanding of its structure, and such problems as drug-enzyme docking may be approached with greater insight. In architecture, the head-mounted display enables clients to better appreciate three-dimensional designs, which may be misinterpreted in their conventional two-dimensional form by untrained eyes. The addition of a treadmill to the system provides additional kinesthetic input into the understanding of building size and scale.

  7. Head Mounted Display with a Roof Mirror Array Fold

    NASA Technical Reports Server (NTRS)

    Olczak, Eugene (Inventor)

    2014-01-01

    The present invention includes a head mounted display (HMD) worn by a user. The HMD includes a display projecting an image through an optical lens. The HMD also includes a one-dimensional retro reflective array receiving the image through the optical lens at a first angle with respect to the display and deflecting the image at a second angle different than the first angle with respect to the display. The one-dimensional retro reflective array reflects the image in order to project the image onto an eye of the user.

  8. Head-mounted workstation displays for airborne reconnaissance applications

    NASA Astrophysics Data System (ADS)

    Browne, Michael P.

    1998-09-01

    Aircraft reconnaissance operators need to access increasing amounts of information to perform their job effectively. Unfortunately, there is no excess weight, space or power capacity in most airborne platforms for the installation of additional display surfaces. Head mounted workstation displays solve these weight, space and power problems and mitigate information overload by providing a user-friendly interface to displayed information. Savings can be tremendous for large platforms. Over 18 kW of power and over 5,000 pounds could be saved on each Rivet Joint or AWACS platform. Even small platforms such as the E-2C or UAV ground control stations benefit from removal of large, heavy CRT or LCD displays. In addition, head mounted workstation displays provide an increased capability for collaborative mission planning and reduce motion-induced nausea. Kaiser Electronics has already designed and demonstrated a prototype system, VIEWTM, that addresses the needs of the airborne workstation operator. This system is easily reconfigured for multiple tasks and can be designed as a portable workstation for use anywhere within the aircraft (especially for maintenance or supervisory roles). We have validated the VIEWTM design with hundreds of user trials within the airborne reconnaissance community. Adopting such a display system in reconnaissance aircraft will gain significant benefits such as longer on-station time, increased operational altitude and improved operator performance.

  9. Practical low-cost stereo head-mounted display

    NASA Astrophysics Data System (ADS)

    Pausch, Randy; Dwivedi, Pramod; Long, Allan C., Jr.

    1991-08-01

    A high-resolution head-mounted display has been developed from substantially cheaper components than previous systems. Monochrome displays provide 720 by 280 monochrome pixels to each eye in a one-inch-square region positioned approximately one inch from each eye. The display hardware is the Private Eye, manufactured by Reflection Technologies, Inc. The tracking system uses the Polhemus Isotrak, providing (x,y,z, azimuth, elevation and roll) information on the user''s head position and orientation 60 times per second. In combination with a modified Nintendo Power Glove, this system provides a full-functionality virtual reality/simulation system. Using two host 80386 computers, real-time wire frame images can be produced. Other virtual reality systems require roughly 250,000 in hardware, while this one requires only 5,000. Stereo is particularly useful for this system because shading or occlusion cannot be used as depth cues.

  10. Design of light field head-mounted display

    NASA Astrophysics Data System (ADS)

    Song, Weitao; Wang, Yongtian; Cheng, Dewen; Liu, Yue

    2014-12-01

    A light field head-mounted display (LF-HMD) using a micro structure array (MSA, lens array or pinhole array) is proposed to realize true three dimensional (3D) display. Dense light field of 3D scene is generated inside the exit pupil of HMD and the viewer can obtain correct depth. This method not only solves the huge data problem in true 3D displays, but also alleviates the visual fatigue in traditional HMDs. Design considerations of LF-HMD system have been analyzed in detail and an optical see-through LF-HMD has been designed using a wedge-shaped freeform prism cemented with a freeform lens and a pinhole array. The experimental result shows that the proposed method is capable of generating a dense light field to obtain a corrected perception of depth.

  11. Differential effects of head-mounted displays on visual performance.

    PubMed

    Schega, Lutz; Hamacher, Daniel; Erfuth, Sandra; Behrens-Baumann, Wolfgang; Reupsch, Juliane; Hoffmann, Michael B

    2014-01-01

    Head-mounted displays (HMDs) virtually augment the visual world to aid visual task completion. Three types of HMDs were compared [look around (LA); optical see-through with organic light emitting diodes and virtual retinal display] to determine whether LA, leaving the observer functionally monocular, is inferior. Response times and error rates were determined for a combined visual search and Go-NoGo task. The costs of switching between displays were assessed separately. Finally, HMD effects on basic visual functions were quantified. Effects of HMDs on visual search and Go-NoGo task were small, but for LA display-switching costs for the Go-NoGo-task the effects were pronounced. Basic visual functions were most affected for LA (reduced visual acuity and visual field sensitivity, inaccurate vergence movements and absent stereo-vision). LA involved comparatively high switching costs for the Go-NoGo task, which might indicate reduced processing of external control cues. Reduced basic visual functions are a likely cause of this effect.

  12. Curved transflective holographic screens for head-mounted display

    NASA Astrophysics Data System (ADS)

    Guillaumée, Mickaël.; Vahdati, Seyed Payam; Tremblay, Eric; Mader, Arnaud; Cadarso, Victor J.; Grossenbacher, Jonas; Brugger, Jürgen; Sprague, Randall; Moser, Christophe

    2013-03-01

    A volume hologram recorded with a lens array is proposed as a transflective screen for Head Worn Display (HWD) systems. Design, fabrication as well as proof of concept are reported. Light from a projection system, with similar properties to one mounted on the side of an eyewear, is efficiently diffracted towards the eye with an angular spread given by the numerical aperture of the lenses forming the lens array. Using a dual-focus contact lens, high-resolution images can be added to the HWD user's normal vision, as light from the surrounding environment is transmitted through the screen with low aberrations. This screen offers the possibility for small footprint and large field of view HWD's.

  13. Gaze contingent hologram synthesis for holographic head-mounted display

    NASA Astrophysics Data System (ADS)

    Hong, Jisoo; Kim, Youngmin; Hong, Sunghee; Shin, Choonsung; Kang, Hoonjong

    2016-03-01

    Development of display and its related technologies provides immersive visual experience with head-mounted-display (HMD). However, most available HMDs provide 3D perception only by stereopsis, lack of accommodation depth cues. Recently, holographic HMD (HHMD) arises as one viable option to resolve this problem because hologram is known to provide full set of depth cues including accommodation. Moreover, by virtue of increasing computational power, hologram synthesis from 3D object represented by point cloud can be calculated in real time even with rigorous Rayleigh-Sommerfeld diffraction formula. However, in HMD, rapid gaze change of the user requires much faster refresh rate, which means that much faster hologram synthesis is indispensable in HHMD. Because the visual acuity falls off in the visual periphery, we propose here to accelerate synthesizing hologram by differentiating density of point cloud projected on the screen. We classify the screen into multiple layers which are concentric circles with different radii, where the center is aligned with gaze of user. Layer with smaller radius is closer to the region of interest, hence, assigned with higher density of point cloud. Because the computation time is directly related to the number of points in point cloud, we can accelerate synthesizing hologram by lowering density of point cloud in the visual periphery. Cognitive study reveals that user cannot discriminate those degradation in the visual periphery if the parameters are properly designed. Prototype HHMD system will be provided for verifying the feasibility of our method, and detailed design scheme will be discussed.

  14. "Head up and eyes out" advances in head mounted displays capabilities

    NASA Astrophysics Data System (ADS)

    Cameron, Alex

    2013-06-01

    There are a host of helmet and head mounted displays, flooding the market place with displays which provide what is essentially a mobile computer display. What sets aviators HMDs apart is that they provide the user with accurate conformal information embedded in the pilots real world view (see through display) where the information presented is intuitive and easy to use because it overlays the real world (mix of sensor imagery, symbolic information and synthetic imagery) and enables them to stay head up, eyes out, - improving their effectiveness, reducing workload and improving safety. Such systems are an enabling technology in the provision of enhanced Situation Awareness (SA) and reducing user workload in high intensity situations. Safety Is Key; so the addition of these HMD functions cannot detract from the aircrew protection functions of conventional aircrew helmets which also include life support and audio communications. These capabilities are finding much wider application in new types of compact man mounted audio/visual products enabled by the emergence of new families of micro displays, novel optical concepts and ultra-compact low power processing solutions. This papers attempts to capture the key drivers and needs for future head mounted systems for aviation applications.

  15. Performance considerations for high-definition head-mounted displays

    NASA Astrophysics Data System (ADS)

    Edwards, Oliver J.; Larimer, James O.; Gille, Jennifer

    1992-07-01

    We will discuss design image-optimization for helmet mounted displays (HMDs) in the context of a system engineering approach that includes a description of natural targets in the field, a description of perceptual characteristics of the human visual system, and device specifications that relate to these ecological and human-factors parameters that ultimately determine task performance. We will consider two HMD system as examples: the GEN III (AN/PVS-7A) night vision goggle (NVG) system and the SIPE helmet system (Soldier''s Integrated Protective Ensemble), both developed by S-TRON for use by the US Army.

  16. Comanche Helmet-Mounted Display Heading-Tape Simulation

    NASA Technical Reports Server (NTRS)

    Turpin, Terry; Dowell, Susan; Atencio, Adolph

    2006-01-01

    The Aeroflightdynamics Directorate (AMRDEC) conducted a simulation to assess the performance associated with a Contact Analog, world-referenced heading tape as implemented on the Comanche Helmet Integrated Display Sight System (HIDSS) when compared with a Compressed heading tape similar to that specified by the former Military Standard (MIL-STD) 1295. Six experienced pilots flew three modified Aeronautical Design Standards (ADS)-33 maneuvers (Hover Turn, Bob-up, Transient Turn) and a precision traffic pattern in the NASA Vertical Motion Simulator (VMS). Analysis of the pilot objective performance data and subjective handling qualities ratings (HQRs) showed the following: Compressed symbology in the Velocity Stabilization (VelStab) flight mode generally produced the most precise performances over Contact Analog symbology with respect to the heading, altitude, position, and time criteria specified for the maneuvers tested. VelStab outperformed the Automatic Flight Control System (AFCS) on all maneuvers achieving desired performance on most maneuvers for both symbol sets. Performance in the AFCS mode was generally desirable to adequate for heading and altitude and did not meet adequate standards for hover position and time for the Hover Turn and Bob-up maneuvers. VelStab and AFCS performance were nearly the same for the Transient Turn. Pilot comments concerning the Contact Analog heading-tape implementation were generally unfavorable in spite of the achieved levels of performance. HQRs showed Compressed symbology in the VelStab flight mode produced the lowest mean HQR, encompassing mixed ratings of satisfactory handling and needing improvement. All other symbology/flight-mode combinations yielded higher HQRs, which characterized opinions that deficiencies in aircraft handling due to HMD symbology would need improvement. Contact Analog heading tape and other symbology require improvement, especially when operating in the AFCS mode. NASA-TLX rated Compressed symbology

  17. Sensor and Display Human Factors Based Design Constraints for Head Mounted and Tele-Operation Systems

    PubMed Central

    Harrison, Andre; Mullins, Linda; Etienne-Cummings, Ralph

    2011-01-01

    For mobile imaging systems in head mounted displays and tele-operation systems it is important to maximize the amount of visual information transmitted to the human visual system without exceeding its input capacity. This paper aims to describe the design constraints on the imager and display systems of head mounted devices and tele-operated systems based upon the capabilities of the human visual system. We also present the experimental results of methods to improve the amount of visual information conveyed to a user when trying to display a high dynamic range image on a low dynamic range display. PMID:22319370

  18. Real-Time Radiometric Compensation for Optical See-Through Head-Mounted Displays.

    PubMed

    Langlotz, Tobias; Cook, Matthew; Regenbrecht, Holger

    2016-11-01

    Optical see-through head-mounted displays are currently seeing a transition out of research labs towards the consumer-oriented market. However, whilst availability has improved and prices have decreased, the technology has not matured much. Most commercially available optical see-through head mounted displays follow a similar principle and use an optical combiner blending the physical environment with digital information. This approach yields problems as the colors for the overlaid digital information can not be correctly reproduced. The perceived pixel colors are always a result of the displayed pixel color and the color of the current physical environment seen through the head-mounted display. In this paper we present an initial approach for mitigating the effect of color-blending in optical see-through head-mounted displays by introducing a real-time radiometric compensation. Our approach is based on a novel prototype for an optical see-through head-mounted display that allows the capture of the current environment as seen by the user's eye. We present three different algorithms using this prototype to compensate color blending in real-time and with pixel-accuracy. We demonstrate the benefits and performance as well as the results of a user study. We see application for all common Augmented Reality scenarios but also for other areas such as Diminished Reality or supporting color-blind people. PMID:27479973

  19. The research on a novel type of the solar-blind UV head-mounted displays

    NASA Astrophysics Data System (ADS)

    Zhao, Shun-long

    2011-08-01

    Ultraviolet technology of detecting is playing a more and more important role in the field of civil application, especially in the corona discharge detection, in modern society. Now the UV imaging detector is one of the most important equipments in power equipment flaws detection. And the modern head-mounted displays (HMDs) have shown the applications in the fields of military, industry production, medical treatment, entertainment, 3D visualization, education and training. We applied the system of head-mounted displays to the UV image detection, and a novel type of head-mounted displays is presented: the solar-blind UV head-mounted displays. And the structure is given. By the solar-blind UV head-mounted displays, a real-time, isometric and visible image of the corona discharge is correctly displayed upon the background scene where it exists. The user will see the visible image of the corona discharge on the real scene rather than on a small screen. Then the user can easily find out the power equipment flaws and repair them. Compared with the traditional UV imaging detector, the introducing of the HMDs simplifies the structure of the whole system. The original visible spectrum optical system is replaced by the eye in the solar-blind UV head-mounted displays. And the optical image fusion technology would be used rather than the digital image fusion system which is necessary in traditional UV imaging detector. That means the visible spectrum optical system and digital image fusion system are not necessary. This makes the whole system cheaper than the traditional UV imaging detector. Another advantage of the solar-blind UV head-mounted displays is that the two hands of user will be free. So while observing the corona discharge the user can do some things about it. Therefore the solar-blind UV head-mounted displays can make the corona discharge expose itself to the user in a better way, and it will play an important role in corona detection in the future.

  20. Headphone and Head-Mounted Visual Displays for Virtual Environments

    NASA Technical Reports Server (NTRS)

    Begault, Duran R.; Ellis, Stephen R.; Wenzel, Elizabeth M.; Trejo, Leonard J. (Technical Monitor)

    1998-01-01

    A realistic auditory environment can contribute to both the overall subjective sense of presence in a virtual display, and to a quantitative metric predicting human performance. Here, the role of audio in a virtual display and the importance of auditory-visual interaction are examined. Conjectures are proposed regarding the effectiveness of audio compared to visual information for creating a sensation of immersion, the frame of reference within a virtual display, and the compensation of visual fidelity by supplying auditory information. Future areas of research are outlined for improving simulations of virtual visual and acoustic spaces. This paper will describe some of the intersensory phenomena that arise during operator interaction within combined visual and auditory virtual environments. Conjectures regarding audio-visual interaction will be proposed.

  1. In the blink of an eye: head mounted displays development within BAE Systems

    NASA Astrophysics Data System (ADS)

    Cameron, Alex

    2015-05-01

    There has been an explosion of interest in head worn displays in recent years, particularly for consumer applications with an attendant ramping up of investment into key enabling technologies to provide what is essence a mobile computer display. However, head mounted system have been around for over 40 years and today's consumer products are building on a legacy of knowledge and technology created by companies such as BAE Systems who have been designing and fielding helmet mounted displays (HMD) for a wide range of specialist applications. Although the dominant application area has been military aviation, solutions have been fielded for solider, ground vehicle, simulation, medical, racing car and even subsea navigation applications. What sets these HMDs apart is that they provide the user with accurate conformal information embedded in the users real world view where the information presented is intuitive and easy to use because it overlays the real world and enables them to stay head up, eyes out, - improving their effectiveness, reducing workload and improving safety. Such systems are an enabling technology in the provision of enhanced Situation Awareness (SA) and reducing user workload in high intensity situations. These capabilities are finding much wider application in new types of compact man mounted audio/visual products enabled by the emergence of new families of micro displays, novel optical concepts and ultra-compact low power processing solutions. This paper therefore provides a personal summary of BAE Systems 40 year's journey in developing and fielding Head Mounted systems, their applications.

  2. Adoption of ASL Classifiers as Delivered by Head-Mounted Displays in a Planetarium Show

    ERIC Educational Resources Information Center

    Hintz, Eric G.; Jones, Michael D.; Lawler, M. Jeannette; Bench, Nathan; Mangrubang, Fred

    2015-01-01

    Accommodating the planetarium experience to members of the deaf or hard-of-hearing community has often created situations that are either disruptive to the rest of the audience or provide an insufficient accommodation. To address this issue, we examined the use of head-mounted displays to deliver an American Sign Language "sound track"…

  3. A high-resolution optical see-through head-mounted display with eyetracking capability.

    PubMed

    Hua, Hong; Hu, Xinda; Gao, Chunyu

    2013-12-16

    A head-mounted display system with fully-integrated eyetracking capability offers multi-fold benefits, not only to fundamental scientific research but also to emerging applications of such technology. A key limitation of the state-of-the-art eyetracked head-mounted display (ET-HMD) technology is the lack of compactness and portability. In this paper, we present an innovative design of a high resolution optical see-through ET-HMD system based on freeform optical technology. A prototype system is demonstrated, which offers a goggle-like compact form factor, non-obstructive see-through field of view and true high-definition image resolution for the virtual display. The see-through view, via the combination of a freeform prism and corrector, achieved better than 0.5 arc minute of angular resolution for the central region of approximately 40-degrees to ensure minimal impacts on the see-through vision of an HMD user.

  4. System requirements for head down and helmet mounted displays in the military avionics environment

    SciTech Connect

    Flynn, M.F.; Kalmanash, M.; Sethna, V.

    1996-12-31

    The introduction of flat panel display technologies into the military avionics cockpit is a challenging proposition, due to the very difficult system level requirements which must be met. These relate to environmental extremes (temperature and vibrational), sever ambient lighting conditions (10,000 fL to nighttime viewing), night vision system compatibility, and wide viewing angle. At the same time, the display system must be packaged in minimal space and use minimal power. The authors will present details on the display system requirements for both head down and helmet mounted systems, as well as information on how these challenges may be overcome.

  5. Surgical navigation with a head-mounted tracking system and display.

    PubMed

    Sadda, Praneeth; Azimi, Ehsan; Jallo, George; Doswell, Jayfus; Kazanzides, Peter

    2013-01-01

    We present the design of a self-contained head-mounted surgical navigation system, which consists of an optical tracking system and an optical see-through head-mounted display (HMD). While the current prototype is bulky, we envision a more compact solution via the eventual integration of the tracking camera(s) into the HMD goggles. Rather than attempting to accurately overlay preoperative models onto the field of view, we adopted a simpler approach of displaying a small "picture-in-picture" virtual view in the HMD. We believe this approach will provide suitable assistance for some image-guided procedures, such as tumor resection, while improving the ergonomics by reducing the need for the surgeon to look away from the patient to view an external monitor. We report the results of initial experiments performed with this system, while preparing for a more clinically realistic study.

  6. Visual Issues In The Use Of A Head-Mounted Monocular Display

    NASA Astrophysics Data System (ADS)

    Peli, Eli

    1989-11-01

    A miniature display device, recently available commercially, is aimed at providing a portable, inexpensive means of visual information communication. The display is head-mounted in front of one eye with the other eye's view of the environment unobstructed. Various visual phenomena are associated with this design. The consequences of these phenomena for visual safety, comfort, and efficiency of the user were evaluated: (1) The monocular, partially occluded mode of operation interrupts binocular vision. Presenting disparate images to each eye results in binocular rivalry. The two images may appear superimposed, with one image perceived with greater clarity or com letely dominant. Most observers can, use the display comfortably in this rivalrous mode. In many cases, it is easier to use the display in a peripheral position, slightly above or below the line of sight, thus permitting normal binocular vision of the environment. (2) As a head-mounted device, the displayed image is perceived to move during head movements due to the response of the vestibulo-ocular reflex. These movements affect the visibility of small letters during active head rotations and sharp accelerations. Adaptation is likely to reduce this perceived image motion. No evidence for postural instability or motion sickness was noted as a result of these conflicts between vis-ual and vestibular inputs. (3) Small displacements of the image are noted even without head motion, resulting from eye movements and the virtual lack of display persiste ce. These movements are noticed sponta e ously by few observers and are unlikely to interfere with the display use in most tasks.

  7. Wide field-of-view digital night vision head-mounted display

    NASA Astrophysics Data System (ADS)

    Browne, Michael P.; Foote, Bobby D.

    2010-04-01

    SA Photonics and Vision Systems International (VSI) are developing an innovative wide field of view digital night vision head mounted display (HMD). This HMD has an 80 degree field of view and has been designed to minimize weight, peripheral obscuration and forward projection. Digital night vision sensors enable electronic image enhancement and VSI's Zero A/C Integration enables the HMD to be integrated with legacy aircraft and provide symbology overlay and recording without the need for an expensive drive electronics box.

  8. Dual-purpose lens for an eye-tracked projection head-mounted display

    NASA Astrophysics Data System (ADS)

    Curatu, Costin; Hua, Hong; Rolland, Jannick

    2007-01-01

    The novel concept of the ET-HMPD, which consists of a Head-Mounted Projection Display (HMPD) with an integrated Eye-Tracking (ET) capability, was recently presented as well as the design of some of its components [Curatu, Hua and Rolland, Proceedings of the SPIE 5875, 2005]. In this paper, we present the overall system design and performance, assuming an ideal cold cube and semi-transparent hot plate.

  9. Optical waveguide technology and its application in head-mounted displays

    NASA Astrophysics Data System (ADS)

    Cameron, Alex

    2012-06-01

    Applying optical waveguide technology to head mounted display (HMD) solutions has the key goal of providing the user with improved tactical situational awareness by providing information and imagery in an easy to use form which also maintains compatibility with current night vision devices and also enables the integration of future night vision devices. The benefits of waveguide technology in HMDs have seen a number of alternative waveguide display technologies and configurations emerge for Head mounted Display applications. BAE System's presented one such technology in 2009 [1] and this is now in production for a range of Helmet Mounted Display products. This paper outlines the key design drivers for aviators Helmet Mounted Displays, provides an update of holographic Optical Waveguide Technology and its maturation into compact, lightweight Helmet Mounted Displays products for aviation and non-aviation applications. Waveguide displays have proved too be a radical enabling technology which allows higher performance display devices solutions to be created in a revolutionary way. It has also provided the user with see through daylight readable displays, offering the combination of very large eye box and excellent real world transmission in a compact format. Holographic Optical Waveguide is an optical technology which reduces size and mass whilst liberating the designer from many of the constraints inherent in conventional optical solutions. This technology is basically a way of moving light without the need for a complex arrangement of conventional lenses. BAE Systems has exploited this technology in the Q-SightTM family of scalable Helmet Mounted Displays; allowing the addition of capability as it is required in a flexible, low-cost way The basic monocular Q-SightTM architecture has been extended to offer wide field of view, monochrome and full colour HMD solution for rotary wing, fast jet and solider system applications. In its basic form Q-SightTM now offers plug

  10. A Depth-Based Head-Mounted Visual Display to Aid Navigation in Partially Sighted Individuals

    PubMed Central

    Hicks, Stephen L.; Wilson, Iain; Muhammed, Louwai; Worsfold, John; Downes, Susan M.; Kennard, Christopher

    2013-01-01

    Independent navigation for blind individuals can be extremely difficult due to the inability to recognise and avoid obstacles. Assistive techniques such as white canes, guide dogs, and sensory substitution provide a degree of situational awareness by relying on touch or hearing but as yet there are no techniques that attempt to make use of any residual vision that the individual is likely to retain. Residual vision can restricted to the awareness of the orientation of a light source, and hence any information presented on a wearable display would have to limited and unambiguous. For improved situational awareness, i.e. for the detection of obstacles, displaying the size and position of nearby objects, rather than including finer surface details may be sufficient. To test whether a depth-based display could be used to navigate a small obstacle course, we built a real-time head-mounted display with a depth camera and software to detect the distance to nearby objects. Distance was represented as brightness on a low-resolution display positioned close to the eyes without the benefit focussing optics. A set of sighted participants were monitored as they learned to use this display to navigate the course. All were able to do so, and time and velocity rapidly improved with practise with no increase in the number of collisions. In a second experiment a cohort of severely sight-impaired individuals of varying aetiologies performed a search task using a similar low-resolution head-mounted display. The majority of participants were able to use the display to respond to objects in their central and peripheral fields at a similar rate to sighted controls. We conclude that the skill to use a depth-based display for obstacle avoidance can be rapidly acquired and the simplified nature of the display may appropriate for the development of an aid for sight-impaired individuals. PMID:23844067

  11. A depth-based head-mounted visual display to aid navigation in partially sighted individuals.

    PubMed

    Hicks, Stephen L; Wilson, Iain; Muhammed, Louwai; Worsfold, John; Downes, Susan M; Kennard, Christopher

    2013-01-01

    Independent navigation for blind individuals can be extremely difficult due to the inability to recognise and avoid obstacles. Assistive techniques such as white canes, guide dogs, and sensory substitution provide a degree of situational awareness by relying on touch or hearing but as yet there are no techniques that attempt to make use of any residual vision that the individual is likely to retain. Residual vision can restricted to the awareness of the orientation of a light source, and hence any information presented on a wearable display would have to limited and unambiguous. For improved situational awareness, i.e. for the detection of obstacles, displaying the size and position of nearby objects, rather than including finer surface details may be sufficient. To test whether a depth-based display could be used to navigate a small obstacle course, we built a real-time head-mounted display with a depth camera and software to detect the distance to nearby objects. Distance was represented as brightness on a low-resolution display positioned close to the eyes without the benefit focussing optics. A set of sighted participants were monitored as they learned to use this display to navigate the course. All were able to do so, and time and velocity rapidly improved with practise with no increase in the number of collisions. In a second experiment a cohort of severely sight-impaired individuals of varying aetiologies performed a search task using a similar low-resolution head-mounted display. The majority of participants were able to use the display to respond to objects in their central and peripheral fields at a similar rate to sighted controls. We conclude that the skill to use a depth-based display for obstacle avoidance can be rapidly acquired and the simplified nature of the display may appropriate for the development of an aid for sight-impaired individuals. PMID:23844067

  12. Wide field-of-view digital night vision head-mounted display

    NASA Astrophysics Data System (ADS)

    Browne, Michael P.

    2011-06-01

    SA Photonics has developed (with support from the Air Force Research Lab, the US Army and Vision Systems International) an innovative wide field of view digital night vision head mounted display (HMD). This HMD has an 80 degree field of view to greatly improve operator situational awareness. By using creating an all-digital system, we provide the capability to enhance and record night vision imagery, overlay symbology, and inset video from remote sensors, either mounted on the aircraft or on UAVs. This HMD has been designed with maximum pilot utility in mind, and is easily stowable without impacting center of gravity or maneuverability of the pilot's head within the cockpit. Because the sensors are digital, they can be located right above the pilot's eyes removing any hyperstereoopsis.

  13. Helmet-mounted display requirements: just another head-up display (HUD) or a different animal altogether?

    NASA Astrophysics Data System (ADS)

    Newman, Richard L.; Haworth, Loran A.

    1994-06-01

    The helmet-mounted display (HMD) presents flight, navigation, and weapon information in the pilot's line of sight. The HMD was developed to allow the pilot to retain aircraft and weapon information while looking off boresight. The present study reviewed the state-of-the-art in HMDs and identified a number of issues applying to HMDs. Several are identical to head-up display (HUD) issues: symbol standardization, excessive clutter, and the need for integration with other cockpit displays and controls. Other issues are unique to the head-mounted display: symbol stabilization, inadequate definitions, undefined symbol drive laws, helmet considerations, and field-of-view (FOV) vs. resolution tradeoff requirements. Symbol stabilization is critical. In the Apache helicopter, the lack of compensation for pilot head motion creates excessive workload during hovering and nap-of-the-earth (NOE) flight. This high workload translates into excessive training requirements. At the same time, misleading symbology makes interpretation of the height of obstructions impossible. The underlying cause is the absence of design criteria for HMDs. The existing military standard does not reflect the current state of technology. In addition, there are inadequate test and evaluation guidelines. The situation parallels the situation for HUDs several years ago.

  14. Monocular 3D see-through head-mounted display via complex amplitude modulation.

    PubMed

    Gao, Qiankun; Liu, Juan; Han, Jian; Li, Xin

    2016-07-25

    The complex amplitude modulation (CAM) technique is applied to the design of the monocular three-dimensional see-through head-mounted display (3D-STHMD) for the first time. Two amplitude holograms are obtained by analytically dividing the wavefront of the 3D object to the real and the imaginary distributions, and then double amplitude-only spatial light modulators (A-SLMs) are employed to reconstruct the 3D images in real-time. Since the CAM technique can inherently present true 3D images to the human eye, the designed CAM-STHMD system avoids the accommodation-convergence conflict of the conventional stereoscopic see-through displays. The optical experiments further demonstrated that the proposed system has continuous and wide depth cues, which enables the observer free of eye fatigue problem. The dynamic display ability is also tested in the experiments and the results showed the possibility of true 3D interactive display. PMID:27464184

  15. Analysis of a head-mounted display-type multifocus display system using a laser scanning method

    NASA Astrophysics Data System (ADS)

    Kim, Dong-Wook; Kwon, Yong-Moo; Park, Q.-Han; Kim, Sung-Kyu

    2011-03-01

    We developed a head-mounted display (HMD)-type multifocus display system using a laser-scanning method to provide an accommodation effect for viewers. This accomplishment indicates that providing a monocular depth cue is possible through this multifocus system. In the system, the optical path is changed by a scanning action. To provide an accurate accommodation effect for the viewer, the multifocus display system is designed and manufactured in accordance with the geometric analysis of the system's scanning action. Using a video camera as a substitute for the viewer, correct focus adjustment without the scanning action problem is demonstrated. By analyzing the scanning action and experimental results, we are able to illustrate the formation of a viewpoint in an HMD-type multifocus display system using a laser-scanning method. In addition, we demonstrate that the accommodation effect could be provided independent of the viewing condition of the viewer.

  16. Hybrid diffractive-refractive optical system design of head-mounted display for augmented reality

    NASA Astrophysics Data System (ADS)

    Zhang, Huijuan

    2005-02-01

    An optical see-through head-mounted display for augmented reality is designed in this paper. Considering the factors, such as the optical performance, the utilization ratios of energy of real world and virtual world, the feelings of users when he wears it and etc., a structure of the optical see-through is adopted. With the characteristics of the particular negative dispersive and the power of realizing random-phase modulation, the diffractive surface is helpful for optical system of reducing weight, simplifying structure and etc., and a diffractive surface is introduced in our optical system. The optical system with 25 mm eye relief, 12 mm exit pupil and 20° (H)x15.4° (V) field-of-view is designed. The utilization ratios of energy of real world and virtual world are 1/4 and 1/2, respectively. The angular resolution of display is 0.27 mrad and it less than that of the minimum of human eyes. The diameter of this system is less than 46mm, and it applies the binocular. This diffractive-refractive optical system of see-through head-mounted display not only satisfies the demands of user"s factors in structure, but also with high resolution, very small chromatic aberration and distortion, and satisfies the need of augmented reality. In the end, the parameters of the diffractive surface are discussed.

  17. A 3D integral imaging optical see-through head-mounted display.

    PubMed

    Hua, Hong; Javidi, Bahram

    2014-06-01

    An optical see-through head-mounted display (OST-HMD), which enables optical superposition of digital information onto the direct view of the physical world and maintains see-through vision to the real world, is a vital component in an augmented reality (AR) system. A key limitation of the state-of-the-art OST-HMD technology is the well-known accommodation-convergence mismatch problem caused by the fact that the image source in most of the existing AR displays is a 2D flat surface located at a fixed distance from the eye. In this paper, we present an innovative approach to OST-HMD designs by combining the recent advancement of freeform optical technology and microscopic integral imaging (micro-InI) method. A micro-InI unit creates a 3D image source for HMD viewing optics, instead of a typical 2D display surface, by reconstructing a miniature 3D scene from a large number of perspective images of the scene. By taking advantage of the emerging freeform optical technology, our approach will result in compact, lightweight, goggle-style AR display that is potentially less vulnerable to the accommodation-convergence discrepancy problem and visual fatigue. A proof-of-concept prototype system is demonstrated, which offers a goggle-like compact form factor, non-obstructive see-through field of view, and true 3D virtual display.

  18. Eyetracked optical see-through head-mounted display as an AAC device

    NASA Astrophysics Data System (ADS)

    Hua, Hong; Hu, Xinda; Gao, Chunyu; Qin, Xiao

    2014-06-01

    An eye-tracked head-mounted display (ET-HMD) system is able to display virtual images as a classical headmounted display (HMD) does, while additionally tracking the gaze direction of the user. An HMD with fullyintegrated eyetracking capability offers multi-fold benefits, not only to fundamental scientific research but also to emerging applications of such technology. A key limitation of the state-of-the-art ET-HMD technology is the lack of compactness and portability. In this paper, we present an innovative design of a high resolution optical see-through ET-HMD system based on freeform optical technology. A prototype system is demonstrated, which offers a goggle-like compact form factor, non-obstructive see-through field of view, true high-definition image resolution for the virtual display, and better than 0.5 arc minute of angular resolution for the see-through view. We will demonstrate the application of the technology as an assistive and augmentative communication (AAC) device.

  19. Optical gesture sensing and depth mapping technologies for head-mounted displays: an overview

    NASA Astrophysics Data System (ADS)

    Kress, Bernard; Lee, Johnny

    2013-05-01

    Head Mounted Displays (HMDs), and especially see-through HMDs have gained renewed interest in recent time, and for the first time outside the traditional military and defense realm, due to several high profile consumer electronics companies presenting their products to hit market. Consumer electronics HMDs have quite different requirements and constrains as their military counterparts. Voice comments are the de-facto interface for such devices, but when the voice recognition does not work (not connection to the cloud for example), trackpad and gesture sensing technologies have to be used to communicate information to the device. We review in this paper the various technologies developed today integrating optical gesture sensing in a small footprint, as well as the various related 3d depth mapping sensors.

  20. Continued Testing of Head-Mounted Displays for Deaf Education in a Planetarium

    NASA Astrophysics Data System (ADS)

    Hintz, Eric G.; Jones, M.; Lawler, J.; Bench, N.; Mangrubang, F. R.

    2013-06-01

    For more than a year now we have been developing techniques for using Head-Mounted Displays (HMD) to help accommodate a deaf audience in a planetarium environment. Our target audience is primarily children from 8 to 13 years of age, but the methodologies can be used for a wide variety of audiences. Applications also extend beyond the planetarium environment. Three tests have been done to determine if American Sign Language (ASL) can be delivered to the HMD and the student view both the planetarium show and the ASL ‘sound track’. From those early results we are now at the point of testing for comprehension improvement on a number of astronomical subjects. We will present a number of these early results.

  1. Semi-parametric color reproduction method for optical see-through head-mounted displays.

    PubMed

    Itoh, Yuta; Dzitsiuk, Maksym; Amano, Toshiyuki; Klinker, Gudrun

    2015-11-01

    The fundamental issues in Augmented Reality (AR) are on how to naturally mediate the reality with virtual content as seen by users. In AR applications with Optical See-Through Head-Mounted Displays (OST-HMD), the issues often raise the problem of rendering color on the OST-HMD consistently to input colors. However, due to various display constraints and eye properties, it is still a challenging task to indistinguishably reproduce the colors on OST-HMDs. An approach to solve this problem is to pre-process the input color so that a user perceives the output color on the display to be the same as the input. We propose a color calibration method for OST-HMDs. We start from modeling the physical optics in the rendering and perception process between the HMD and the eye. We treat the color distortion as a semi-parametric model which separates the non-linear color distortion and the linear color shift. We demonstrate that calibrated images regain their original appearance on two OST-HMD setups with both synthetic and real datasets. Furthermore, we analyze the limitations of the proposed method and remaining problems of the color reproduction in OST-HMDs. We then discuss how to realize more practical color reproduction methods for future HMD-eye system.

  2. An automated calibration method for non-see-through head mounted displays

    PubMed Central

    Gilson, Stuart J.; Fitzgibbon, Andrew W.; Glennerster, Andrew

    2011-01-01

    Accurate calibration of a head mounted display (HMD) is essential both for research on the visual system and for realistic interaction with virtual objects. Yet, existing calibration methods are time consuming and depend on human judgements, making them error prone, and are often limited to optical see-through HMDs. Building on our existing approach to HMD calibration Gilson et al. (2008), we show here how it is possible to calibrate a non-see-through HMD. A camera is placed inside a HMD displaying an image of a regular grid, which is captured by the camera. The HMD is then removed and the camera, which remains fixed in position, is used to capture images of a tracked calibration object in multiple positions. The centroids of the markers on the calibration object are recovered and their locations re-expressed in relation to the HMD grid. This allows established camera calibration techniques to be used to recover estimates of the HMD display's intrinsic parameters (width, height, focal length) and extrinsic parameters (optic centre and orientation of the principal ray). We calibrated a HMD in this manner and report the magnitude of the errors between real image features and reprojected features. Our calibration method produces low reprojection errors without the need for error-prone human judgements. PMID:21620891

  3. Compact three-dimensional head-mounted display system with Savart plate.

    PubMed

    Lee, Chang-Kun; Moon, Seokil; Lee, Seungjae; Yoo, Dongheon; Hong, Jong-Young; Lee, Byoungho

    2016-08-22

    We propose three-dimensional (3D) head-mounted display (HMD) providing multi-focal and wearable functions by using polarization-dependent optical path switching in Savart plate. The multi-focal function is implemented as micro display with high pixel density of 1666 pixels per inches is optically duplicated in longitudinal direction according to the polarization state. The combination of micro display, fast switching polarization rotator and Savart plate retains small form factor suitable for wearable function. The optical aberrations of duplicated panels are investigated by ray tracing according to both wavelength and polarization state. Astigmatism and lateral chromatic aberration of extraordinary wave are compensated by modification of the Savart plate and sub-pixel shifting method, respectively. To verify the feasibility of the proposed system, a prototype of the HMD module for monocular eye is implemented. The module has the compact size of 40 mm by 90 mm by 40 mm and the weight of 131 g with wearable function. The micro display and polarization rotator are synchronized in real-time as 30 Hz and two focal planes are formed at 640 and 900 mm away from eye box, respectively. In experiments, the prototype also provides augmented reality function by combining the optically duplicated panels with a beam splitter. The multi-focal function of the optically duplicated panels without astigmatism and color dispersion compensation is verified. When light field optimization for two additive layers is performed, perspective images are observed, and the integration of real world scene and high quality 3D images is confirmed. PMID:27557230

  4. Optical see-through head-mounted display with occlusion capability

    NASA Astrophysics Data System (ADS)

    Gao, Chunyu; Lin, Yuxiang; Hua, Hong

    2013-05-01

    Lack of mutual occlusion capability between computer-rendered and real objects is one of fundamental problems for most existing optical see-through head-mounted displays (OST-HMD). Without the proper occlusion management, the virtual view through an OST-HMD appears "ghost-like", floating in the real world. To address this challenge, we have developed an innovative optical scheme that uniquely combines the eyepiece and see-through relay optics to achieve an occlusion-capable OST-HMD system with a very compelling form factor and high optical performances. The proposed display system was based on emerging freeform optical design technologies and was designed for highly efficient liquid crystal on silicon (LCoS) type spatial light modulator (SLM) and bright Organic LED (OLED) microdisplay. The proposed display technology was capable of working in both indoor and outdoor environments. Our current design offered a 1280x1024 color resolution based on 0.8" microdisplay and SLM. The MTF values for the majority of the fields at the cutoff frequency of 40lps/mm, which is determined by the pixel size of the microdisplay, are better than 15%. The design achieved a diagonal FOV of 40 degrees, 31.7 degrees horizontally and 25.6 degrees vertically, an exit pupil diameter of 8mm (non-vignetted), and an eye clearance of 18mm. The optics weights about 20 grams per eye. Our proposed occlusion capable OST-HMD system can easily find myriads of applications in various military and commercial sectors such as military training, gaming and entertainment.

  5. Corneal-Imaging Calibration for Optical See-Through Head-Mounted Displays.

    PubMed

    Plopski, Alexander; Itoh, Yuta; Nitschke, Christian; Kiyokawa, Kiyoshi; Klinker, Gudrun; Takemura, Haruo

    2015-04-01

    In recent years optical see-through head-mounted displays (OST-HMDs) have moved from conceptual research to a market of mass-produced devices with new models and applications being released continuously. It remains challenging to deploy augmented reality (AR) applications that require consistent spatial visualization. Examples include maintenance, training and medical tasks, as the view of the attached scene camera is shifted from the user's view. A calibration step can compute the relationship between the HMD-screen and the user's eye to align the digital content. However, this alignment is only viable as long as the display does not move, an assumption that rarely holds for an extended period of time. As a consequence, continuous recalibration is necessary. Manual calibration methods are tedious and rarely support practical applications. Existing automated methods do not account for user-specific parameters and are error prone. We propose the combination of a pre-calibrated display with a per-frame estimation of the user's cornea position to estimate the individual eye center and continuously recalibrate the system. With this, we also obtain the gaze direction, which allows for instantaneous uncalibrated eye gaze tracking, without the need for additional hardware and complex illumination. Contrary to existing methods, we use simple image processing and do not rely on iris tracking, which is typically noisy and can be ambiguous. Evaluation with simulated and real data shows that our approach achieves a more accurate and stable eye pose estimation, which results in an improved and practical calibration with a largely improved distribution of projection error. PMID:26357098

  6. Rapid P300 brain-computer interface communication with a head-mounted display

    PubMed Central

    Käthner, Ivo; Kübler, Andrea; Halder, Sebastian

    2015-01-01

    Visual ERP (P300) based brain-computer interfaces (BCIs) allow for fast and reliable spelling and are intended as a muscle-independent communication channel for people with severe paralysis. However, they require the presentation of visual stimuli in the field of view of the user. A head-mounted display could allow convenient presentation of visual stimuli in situations, where mounting a conventional monitor might be difficult or not feasible (e.g., at a patient's bedside). To explore if similar accuracies can be achieved with a virtual reality (VR) headset compared to a conventional flat screen monitor, we conducted an experiment with 18 healthy participants. We also evaluated it with a person in the locked-in state (LIS) to verify that usage of the headset is possible for a severely paralyzed person. Healthy participants performed online spelling with three different display methods. In one condition a 5 × 5 letter matrix was presented on a conventional 22 inch TFT monitor. Two configurations of the VR headset were tested. In the first (glasses A), the same 5 × 5 matrix filled the field of view of the user. In the second (glasses B), single letters of the matrix filled the field of view of the user. The participant in the LIS tested the VR headset on three different occasions (glasses A condition only). For healthy participants, average online spelling accuracies were 94% (15.5 bits/min) using three flash sequences for spelling with the monitor and glasses A and 96% (16.2 bits/min) with glasses B. In one session, the participant in the LIS reached an online spelling accuracy of 100% (10 bits/min) using the glasses A condition. We also demonstrated that spelling with one flash sequence is possible with the VR headset for healthy users (mean: 32.1 bits/min, maximum reached by one user: 71.89 bits/min at 100% accuracy). We conclude that the VR headset allows for rapid P300 BCI communication in healthy users and may be a suitable display option for severely

  7. Rapid P300 brain-computer interface communication with a head-mounted display.

    PubMed

    Käthner, Ivo; Kübler, Andrea; Halder, Sebastian

    2015-01-01

    Visual ERP (P300) based brain-computer interfaces (BCIs) allow for fast and reliable spelling and are intended as a muscle-independent communication channel for people with severe paralysis. However, they require the presentation of visual stimuli in the field of view of the user. A head-mounted display could allow convenient presentation of visual stimuli in situations, where mounting a conventional monitor might be difficult or not feasible (e.g., at a patient's bedside). To explore if similar accuracies can be achieved with a virtual reality (VR) headset compared to a conventional flat screen monitor, we conducted an experiment with 18 healthy participants. We also evaluated it with a person in the locked-in state (LIS) to verify that usage of the headset is possible for a severely paralyzed person. Healthy participants performed online spelling with three different display methods. In one condition a 5 × 5 letter matrix was presented on a conventional 22 inch TFT monitor. Two configurations of the VR headset were tested. In the first (glasses A), the same 5 × 5 matrix filled the field of view of the user. In the second (glasses B), single letters of the matrix filled the field of view of the user. The participant in the LIS tested the VR headset on three different occasions (glasses A condition only). For healthy participants, average online spelling accuracies were 94% (15.5 bits/min) using three flash sequences for spelling with the monitor and glasses A and 96% (16.2 bits/min) with glasses B. In one session, the participant in the LIS reached an online spelling accuracy of 100% (10 bits/min) using the glasses A condition. We also demonstrated that spelling with one flash sequence is possible with the VR headset for healthy users (mean: 32.1 bits/min, maximum reached by one user: 71.89 bits/min at 100% accuracy). We conclude that the VR headset allows for rapid P300 BCI communication in healthy users and may be a suitable display option for severely

  8. Design of monocular head-mounted displays for increased indoor firefighting safety and efficiency

    NASA Astrophysics Data System (ADS)

    Wilson, Joel; Steingart, Dan; Romero, Russell; Reynolds, Jessica; Mellers, Eric; Redfern, Andrew; Lim, Lloyd; Watts, William; Patton, Colin; Baker, Jessica; Wright, Paul

    2005-05-01

    Four monocular Head-Mounted Display (HMD) prototypes from the Fire Information and Rescue Equipment (FIRE) project at UC Berkeley are presented. The FIRE project aims to give firefighters a system of information technology tools for safer and more efficient firefighting in large buildings. The paper begins by describing the FIRE project and its use of a custom wireless sensor network (WSN) called SmokeNet for personnel tracking. The project aims to address urban/industrial firefighting procedures in need of improvement. Two "user-needs" studies with the Chicago and Berkeley Fire Departments are briefly presented. The FIRE project"s initial HMD prototype designs are then discussed with regard to feedback from the user-needs studies. These prototypes are evaluated in their potential costs and benefits to firefighters and found to need improvement. Next, some currently available commercial HMDs are reviewed and compared in their cost, performance, and potential for use by firefighters. Feedback from the Berkeley Fire Department user-needs study, in which the initial prototypes were demonstrated, is compiled into a concept selection matrix for the next prototypes. This matrix is used to evaluate a variety of HMDs, including some of the commercial units presented, and to select the best design options. Finally, the current prototypes of the two best design options are presented and discussed.

  9. Visual Evoked Potential Using Head-Mounted Display Versus Cathode Ray Tube: A Pilot Study

    PubMed Central

    Choi, Hyo Seon; Im, Sang Hee; Kim, Yong Kyun

    2016-01-01

    Objective To present a new stimulation method based on the use of a head-mounted display (HMD) during pattern reversal visual evoked potential (PR-VEP) testing and to compare variables of HMD to those of conventional cathode ray tube (CRT). Methods Twenty-three normal subjects without visual problems were recruited. PR-VEPs were generated using CRT or HMD stimuli. VEP outcome measures included latencies (N75, P100, and N145) and peak-to-peak amplitudes (N75–P100 and P100–N145). Subjective discomfort associated with HMD was determined using a self-administered questionnaire. Results PR-VEPs generated by HMD stimuli showed typical triphasic waveforms, the components of which were found to be correlated with those obtained using conventional CRT stimuli. Self-administered discomfort questionnaires revealed that HMD was more comfortable in some aspects. It allowed subjects to concentrate better than CRT. Conclusion The described HMD stimulation can be used as an alternative to the standard CRT stimulation for PR-VEPs. PR-VEP testing using HMD has potential applications in clinical practice and visual system research because HMD can be used on a wider range of subjects compared to CRT. PMID:27152285

  10. Binocular Convergence and Errors in Judged Distance While Using Head-mounted See-through Displays

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Bucher, Urs J.; Menges, Brian M.; Null, Cynthia H. (Technical Monitor)

    1995-01-01

    Previous observations have shown that optical superposition of a physical backdrops at the judged depth of a stereoscopic virtual image moves the judged depth closer to the observer. This effect was more pronounced for slowly moving physical backdrops and was not enhanced when the virtual image was rendered as a flat shaded solid object rather than a open wire-frame. Since this change in rendering making the virtual image more completely occlude the backdrop did not effect its judged depth and since the motion of the backdrop which would have attracted visual attention and binocular convergence did Increase its perceptual displacement, it was concluded that the change In Judged depth was not due to the perceived occlusion. Rather it was concluded to be due to an increase in binocular convergence. An experimental test of this hypothesis using a unobtrusive nonius technique to detect absolute and relative convergence has confirmed the presence of convergence correlated with the magnitude of the change in judged position of this virtual Image. The practical implications of this cause are demonstrated by a second study using monocular, biocular and stereoscopic viewing conditions and the consequences for the design of head-mounted see-through displays for near work are discussed.

  11. Recognition of American Sign Language (ASL) Classifiers in a Planetarium Using a Head-Mounted Display

    NASA Astrophysics Data System (ADS)

    Hintz, Eric G.; Jones, Michael; Lawler, Jeannette; Bench, Nathan

    2015-01-01

    A traditional accommodation for the deaf or hard-of-hearing in a planetarium show is some type of captioning system or a signer on the floor. Both of these have significant drawbacks given the nature of a planetarium show. Young audience members who are deaf likely don't have the reading skills needed to make a captioning system effective. A signer on the floor requires light which can then splash onto the dome. We have examined the potential of using a Head-Mounted Display (HMD) to provide an American Sign Language (ASL) translation. Our preliminary test used a canned planetarium show with a pre-recorded sound track. Since many astronomical objects don't have official ASL signs, the signer had to use classifiers to describe the different objects. Since these are not official signs, these classifiers provided a way to test to see if students were picking up the information using the HMD.We will present results that demonstrate that the use of HMDs is at least as effective as projecting a signer on the dome. This also showed that the HMD could provide the necessary accommodation for students for whom captioning was ineffective. We will also discuss the current effort to provide a live signer without the light splash effect and our early results on teaching effectiveness with HMDs.This work is partially supported by funding from the National Science Foundation grant IIS-1124548 and the Sorenson Foundation.

  12. Development of an immersive virtual reality head-mounted display with high performance.

    PubMed

    Wang, Yunqi; Liu, Weiqi; Meng, Xiangxiang; Fu, Hanyi; Zhang, Daliang; Kang, Yusi; Feng, Rui; Wei, Zhonglun; Zhu, Xiuqing; Jiang, Guohua

    2016-09-01

    To resolve the contradiction between large field of view and high resolution in immersive virtual reality (VR) head-mounted displays (HMDs), an HMD monocular optical system with a large field of view and high resolution was designed. The system was fabricated by adopting aspheric technology with CNC grinding and a high-resolution LCD as the image source. With this monocular optical system, an HMD binocular optical system with a wide-range continuously adjustable interpupillary distance was achieved in the form of partially overlapping fields of view (FOV) combined with a screw adjustment mechanism. A fast image processor-centered LCD driver circuit and an image preprocessing system were also built to address binocular vision inconsistency in the partially overlapping FOV binocular optical system. The distortions of the HMD optical system with a large field of view were measured. Meanwhile, the optical distortions in the display and the trapezoidal distortions introduced during image processing were corrected by a calibration model for reverse rotations and translations. A high-performance not-fully-transparent VR HMD device with high resolution (1920×1080) and large FOV [141.6°(H)×73.08°(V)] was developed. The full field-of-view average value of angular resolution is 18.6  pixels/degree. With the device, high-quality VR simulations can be completed under various scenarios, and the device can be utilized for simulated trainings in aeronautics, astronautics, and other fields with corresponding platforms. The developed device has positive practical significance. PMID:27607272

  13. Development of an immersive virtual reality head-mounted display with high performance.

    PubMed

    Wang, Yunqi; Liu, Weiqi; Meng, Xiangxiang; Fu, Hanyi; Zhang, Daliang; Kang, Yusi; Feng, Rui; Wei, Zhonglun; Zhu, Xiuqing; Jiang, Guohua

    2016-09-01

    To resolve the contradiction between large field of view and high resolution in immersive virtual reality (VR) head-mounted displays (HMDs), an HMD monocular optical system with a large field of view and high resolution was designed. The system was fabricated by adopting aspheric technology with CNC grinding and a high-resolution LCD as the image source. With this monocular optical system, an HMD binocular optical system with a wide-range continuously adjustable interpupillary distance was achieved in the form of partially overlapping fields of view (FOV) combined with a screw adjustment mechanism. A fast image processor-centered LCD driver circuit and an image preprocessing system were also built to address binocular vision inconsistency in the partially overlapping FOV binocular optical system. The distortions of the HMD optical system with a large field of view were measured. Meanwhile, the optical distortions in the display and the trapezoidal distortions introduced during image processing were corrected by a calibration model for reverse rotations and translations. A high-performance not-fully-transparent VR HMD device with high resolution (1920×1080) and large FOV [141.6°(H)×73.08°(V)] was developed. The full field-of-view average value of angular resolution is 18.6  pixels/degree. With the device, high-quality VR simulations can be completed under various scenarios, and the device can be utilized for simulated trainings in aeronautics, astronautics, and other fields with corresponding platforms. The developed device has positive practical significance.

  14. Application of virtual reality head mounted display for investigation of movement: a novel effect of orientation of attention

    NASA Astrophysics Data System (ADS)

    Quinlivan, Brendan; Butler, John S.; Beiser, Ines; Williams, Laura; McGovern, Eavan; O'Riordan, Sean; Hutchinson, Michael; Reilly, Richard B.

    2016-10-01

    Objective. To date human kinematics research has relied on video processing, motion capture and magnetic search coil data acquisition techniques. However, the use of head mounted display virtual reality systems, as a novel research tool, could facilitate novel studies into human movement and movement disorders. These systems have the unique ability of presenting immersive 3D stimulus while also allowing participants to make ecologically valid movement-based responses. Approach. We employed one such system (Oculus Rift DK2) in this study to present visual stimulus and acquire head-turn data from a cohort of 40 healthy adults. Participants were asked to complete head movements towards eccentrically located visual targets following valid and invalid cues. Such tasks are commonly employed for investigating the effects orientation of attention and are known as Posner cueing paradigms. Electrooculography was also recorded for a subset of 18 participants. Main results. A delay was observed in onset of head movement and saccade onset during invalid trials, both at the group and single participant level. We found that participants initiated head turns 57.4 ms earlier during valid trials. A strong relationship between saccade onset and head movement onset was also observed during valid trials. Significance. This work represents the first time that the Posner cueing effect has been observed in onset of head movement in humans. The results presented here highlight the role of head-mounted display systems as a novel and practical research tool for investigations of normal and abnormal movement patterns.

  15. Effects on visual functions during tasks of object handling in virtual environment with a head mounted display.

    PubMed

    Kawara, T; Ohmi, M; Yoshizawa, T

    1996-11-01

    This study examined the effects on visual functions of a prolonged handling task within the helmet-mounted display environment. Both version eye movement and accommodative response became gradually slower during the 40-min task. Although delayed presentation of display after head movement noticeably worsened both visual responses, presentation delay after hand movement did not significantly change the sluggishness of responses. Therefore it is suggested that decreasing time delay after head movement is a more important factor in order to improve human performance of handling tasks within the HMD environment.

  16. Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

    PubMed

    Nalivaiko, Eugene; Davis, Simon L; Blackmore, Karen L; Vakulin, Andrew; Nesbitt, Keith V

    2015-11-01

    Evidence from studies of provocative motion indicates that motion sickness is tightly linked to the disturbances of thermoregulation. The major aim of the current study was to determine whether provocative visual stimuli (immersion into the virtual reality simulating rides on a rollercoaster) affect skin temperature that reflects thermoregulatory cutaneous responses, and to test whether such stimuli alter cognitive functions. In 26 healthy young volunteers wearing head-mounted display (Oculus Rift), simulated rides consistently provoked vection and nausea, with a significant difference between the two versions of simulation software (Parrot Coaster and Helix). Basal finger temperature had bimodal distribution, with low-temperature group (n=8) having values of 23-29 °C, and high-temperature group (n=18) having values of 32-36 °C. Effects of cybersickness on finger temperature depended on the basal level of this variable: in subjects from former group it raised by 3-4 °C, while in most subjects from the latter group it either did not change or transiently reduced by 1.5-2 °C. There was no correlation between the magnitude of changes in the finger temperature and nausea score at the end of simulated ride. Provocative visual stimulation caused prolongation of simple reaction time by 20-50 ms; this increase closely correlated with the subjective rating of nausea. Lastly, in subjects who experienced pronounced nausea, heart rate was elevated. We conclude that cybersickness is associated with changes in cutaneous thermoregulatory vascular tone; this further supports the idea of a tight link between motion sickness and thermoregulation. Cybersickness-induced prolongation of reaction time raises obvious concerns regarding the safety of this technology. PMID:26340855

  17. Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

    PubMed

    Nalivaiko, Eugene; Davis, Simon L; Blackmore, Karen L; Vakulin, Andrew; Nesbitt, Keith V

    2015-11-01

    Evidence from studies of provocative motion indicates that motion sickness is tightly linked to the disturbances of thermoregulation. The major aim of the current study was to determine whether provocative visual stimuli (immersion into the virtual reality simulating rides on a rollercoaster) affect skin temperature that reflects thermoregulatory cutaneous responses, and to test whether such stimuli alter cognitive functions. In 26 healthy young volunteers wearing head-mounted display (Oculus Rift), simulated rides consistently provoked vection and nausea, with a significant difference between the two versions of simulation software (Parrot Coaster and Helix). Basal finger temperature had bimodal distribution, with low-temperature group (n=8) having values of 23-29 °C, and high-temperature group (n=18) having values of 32-36 °C. Effects of cybersickness on finger temperature depended on the basal level of this variable: in subjects from former group it raised by 3-4 °C, while in most subjects from the latter group it either did not change or transiently reduced by 1.5-2 °C. There was no correlation between the magnitude of changes in the finger temperature and nausea score at the end of simulated ride. Provocative visual stimulation caused prolongation of simple reaction time by 20-50 ms; this increase closely correlated with the subjective rating of nausea. Lastly, in subjects who experienced pronounced nausea, heart rate was elevated. We conclude that cybersickness is associated with changes in cutaneous thermoregulatory vascular tone; this further supports the idea of a tight link between motion sickness and thermoregulation. Cybersickness-induced prolongation of reaction time raises obvious concerns regarding the safety of this technology.

  18. EMU helmet mounted display

    NASA Technical Reports Server (NTRS)

    Marmolejo, Jose (Inventor); Smith, Stephen (Inventor); Plough, Alan (Inventor); Clarke, Robert (Inventor); Mclean, William (Inventor); Fournier, Joseph (Inventor)

    1990-01-01

    A helmet mounted display device is disclosed for projecting a display on a flat combiner surface located above the line of sight where the display is produced by two independent optical channels with independent LCD image generators. The display has a fully overlapped field of view on the combiner surface and the focus can be adjusted from a near field of four feet to infinity.

  19. Visual cueing considerations in Nap-of-the-Earth helicopter flight head-slaved helmet-mounted displays

    NASA Technical Reports Server (NTRS)

    Grunwald, Arthur J.; Kohn, Silvia

    1993-01-01

    The pilot's ability to derive Control-Oriented Visual Field Information from teleoperated Helmet-Mounted displays in Nap-of-the-Earth flight, is investigated. The visual field with these types of displays, commonly used in Apache and Cobra helicopter night operations, originates from a relatively narrow field-of-view Forward Looking Infrared Radiation Camera, gimbal-mounted at the nose of the aircraft and slaved to the pilot's line-of-sight, in order to obtain a wide-angle field-of-regard. Pilots have encountered considerable difficulties in controlling the aircraft by these devices. Experimental simulator results presented here indicate that part of these difficulties can be attributed to head/camera slaving system phase lags and errors. In the presence of voluntary head rotation, these slaving system imperfections are shown to impair the Control-Oriented Visual Field Information vital in vehicular control, such as the perception of the anticipated flight path or the vehicle yaw rate. Since, in the presence of slaving system imperfections, the pilot will tend to minimize head rotation, the full wide-angle field-of-regard of the line-of-sight slaved Helmet-Mounted Display, is not always fully utilized.

  20. Lightweight high-brightness helmet-mounted head-up display system

    NASA Astrophysics Data System (ADS)

    Wagner, Mathieu; North, Thibault; Bourquin, Stéphane; Kilcher, Lucio

    2016-03-01

    We present a compact binocular head-up display for integration in a motorcycle helmet. A 2D MEMS-mirror reflecting laser beams enables the formation of a bright image superimposed on the user vision by means of retinal scanning. A 3d-printed prototype including the required optical components is presented and characterized. It fits the morphology of most users thanks to several degrees of freedom accessible to the user for fine-tuning.

  1. Design of an ultralight head-mounted projective display (HMPD) and its applications in augmented collaborative environments

    NASA Astrophysics Data System (ADS)

    Hua, Hong; Gao, Chunyu; Brown, Leonard; Biocca, Frank; Rolland, Jannick P.

    2002-05-01

    Head-mounted displays (HMDs) are widely used for 3D visualization tasks such as surgical planning, scientific visualization, or engineering design. Even though the HMD technologies have undergone great development, tradeoffs in capability and limitation exist. The concept of head-mounted projective displays (HMPDs) is an emerging technology on the boundary of conventional HMDs and projective displays such as the CAVE technology. It has been recently demonstrated to yield 3D visualization capability with potentially a large FOV, lightweight optics, low distortion, as well as correct occlusion of virtual objects by real objects. As such, the HMPD has been proposed as an alternative to stereoscopic displays for 3D visualization applications. In this paper, a brief review the HMPD technology is followed by the presentation of a recent design and implementation of a compact HMPD prototype based on an ultra-light design of projective optics using diffractive optical element (DOE) and plastic components. Finally, we will include applications of the HMPD technology being developed across three universities for augmented visualization tasks and distributed collaboration in augmented environments.

  2. Development of a surgical navigation system based on augmented reality using an optical see-through head-mounted display.

    PubMed

    Chen, Xiaojun; Xu, Lu; Wang, Yiping; Wang, Huixiang; Wang, Fang; Zeng, Xiangsen; Wang, Qiugen; Egger, Jan

    2015-06-01

    The surgical navigation system has experienced tremendous development over the past decades for minimizing the risks and improving the precision of the surgery. Nowadays, Augmented Reality (AR)-based surgical navigation is a promising technology for clinical applications. In the AR system, virtual and actual reality are mixed, offering real-time, high-quality visualization of an extensive variety of information to the users (Moussa et al., 2012) [1]. For example, virtual anatomical structures such as soft tissues, blood vessels and nerves can be integrated with the real-world scenario in real time. In this study, an AR-based surgical navigation system (AR-SNS) is developed using an optical see-through HMD (head-mounted display), aiming at improving the safety and reliability of the surgery. With the use of this system, including the calibration of instruments, registration, and the calibration of HMD, the 3D virtual critical anatomical structures in the head-mounted display are aligned with the actual structures of patient in real-world scenario during the intra-operative motion tracking process. The accuracy verification experiment demonstrated that the mean distance and angular errors were respectively 0.809±0.05mm and 1.038°±0.05°, which was sufficient to meet the clinical requirements.

  3. LIBS system with compact fiber spectrometer, head mounted spectra display and hand held eye-safe erbium glass laser gun

    NASA Astrophysics Data System (ADS)

    Myers, Michael J.; Myers, John D.; Sarracino, John T.; Hardy, Christopher R.; Guo, Baoping; Christian, Sean M.; Myers, Jeffrey A.; Roth, Franziska; Myers, Abbey G.

    2010-02-01

    LIBS (Laser Induced Breakdown Spectroscopy) systems are capable of real-time chemical analysis with little or no sample preparation. A Q-switched laser is configured such that laser induced plasma is produced on targeted material. Chemical element line spectra are created, collected and analyzed by a fiber spectrometer. Line spectra emission data is instantly viewed on a head mounted display. "Eye-safe" Class I erbium glass lasers provide for insitu LIBS applications without the need for eye-protection goggles. This is due to the fact that Megawatt peak power Q-switched lasers operating in the narrow spectral window between 1.5um and 1.6um are approximately 8000 times more "eye-safe" than other laser devices operating in the UV, visible and near infrared. In this work we construct and demonstrate a LIBS system that includes a hand held eye-safe laser gun. The laser gun is fitted with a micro-integrating sphere in-situ target interface and is designed to facilitate chemical analysis in remote locations. The laser power supply, battery pack, computer controller and spectrophotometer components are packaged into a utility belt. A head mounted display is employed for "hands free" viewing of the emitted line spectra. The system demonstrates that instant qualitative and semi-quantitative chemical analyses may be performed in remote locations utilizing lightweight commercially available system components ergonomically fitted to the operator.

  4. Helmet-Mounted Liquid-Crystal Display

    NASA Technical Reports Server (NTRS)

    Smith, Steve; Plough, Alan; Clarke, Robert; Mclean, William; Fournier, Joseph; Marmolejo, Jose A.

    1991-01-01

    Helmet-mounted binocular display provides text and images for almost any wearer; does not require fitting for most users. Accommodates users from smallest interpupillary distance to largest. Two liquid-crystal display units mounted in helmet. Images generated seen from any position head can assume inside helmet. Eyes directed to position for best viewing.

  5. The influence of depth of focus on visibility of monocular head-mounted display symbology in simulation and training applications

    NASA Astrophysics Data System (ADS)

    Winterbottom, Marc D.; Patterson, Robert; Pierce, Byron J.; Covas, Christine; Winner, Jennifer

    2005-05-01

    The Joint Helmet Mounted Cueing System (JHMCS),is being considered for integration into the F-15, F-16, and F-18 aircraft. If this integration occurs, similar monocular head-mounted displays (HMDs) will need to be integrated with existing out-the-window simulator systems for training purposes. One such system is the Mobile Modular Display for Advanced Research and Training (M2DART), which is constructed with flat-panel rear-projection screens around a nominal eye-point. Because the panels are flat, the distance from the eye point to the display screen varies depending upon the location on the screen to which the observer is directing fixation. Variation in focal distance may create visibility problems for either the HMD symbology or the out-the-window imagery presented on the simulator rear-projection display screen because observers may not be able to focus both sets of images simultaneously. The extent to which blurring occurs will depend upon the difference between the focal planes of the simulator display and HMD as well as the depth of focus of the observer. In our psychophysical study, we investigated whether significant blurring occurs as a result of such differences in focal distances and established an optimal focal distance for an HMD which would minimize blurring for a range of focal distances representative of the M2DART. Our data suggest that blurring of symbology due to differing focal planes is not a significant issue within the range of distances tested and that the optimal focal distance for an HMD is the optical midpoint between the near and far rear-projection screen distances.

  6. 3D optical see-through head-mounted display based augmented reality system and its application

    NASA Astrophysics Data System (ADS)

    Zhang, Zhenliang; Weng, Dongdong; Liu, Yue; Xiang, Li

    2015-07-01

    The combination of health and entertainment becomes possible due to the development of wearable augmented reality equipment and corresponding application software. In this paper, we implemented a fast calibration extended from SPAAM for an optical see-through head-mounted display (OSTHMD) which was made in our lab. During the calibration, the tracking and recognition techniques upon natural targets were used, and the spatial corresponding points had been set in dispersed and well-distributed positions. We evaluated the precision of this calibration, in which the view angle ranged from 0 degree to 70 degrees. Relying on the results above, we calculated the position of human eyes relative to the world coordinate system and rendered 3D objects in real time with arbitrary complexity on OSTHMD, which accurately matched the real world. Finally, we gave the degree of satisfaction about our device in the combination of entertainment and prevention of cervical vertebra diseases through user feedbacks.

  7. Optical See-Through Head Mounted Display Direct Linear Transformation Calibration Robustness in the Presence of User Alignment Noise

    NASA Technical Reports Server (NTRS)

    Axholt, Magnus; Skoglund, Martin; Peterson, Stephen D.; Cooper, Matthew D.; Schoen, Thomas B.; Gustafsson, Fredrik; Ynnerman, Anders; Ellis, Stephen R.

    2010-01-01

    Augmented Reality (AR) is a technique by which computer generated signals synthesize impressions that are made to coexist with the surrounding real world as perceived by the user. Human smell, taste, touch and hearing can all be augmented, but most commonly AR refers to the human vision being overlaid with information otherwise not readily available to the user. A correct calibration is important on an application level, ensuring that e.g. data labels are presented at correct locations, but also on a system level to enable display techniques such as stereoscopy to function properly [SOURCE]. Thus, vital to AR, calibration methodology is an important research area. While great achievements already have been made, there are some properties in current calibration methods for augmenting vision which do not translate from its traditional use in automated cameras calibration to its use with a human operator. This paper uses a Monte Carlo simulation of a standard direct linear transformation camera calibration to investigate how user introduced head orientation noise affects the parameter estimation during a calibration procedure of an optical see-through head mounted display.

  8. Effect of eye position on the projected stimulus distance in a binocular head-mounted display

    NASA Astrophysics Data System (ADS)

    McCandless, Jeffrey W.; Ellis, Stephen R.

    2000-05-01

    During vergence eye movements, the effective separation between the two eyes varies because the nodal point of each eye is offset from the center of rotation. As a result, the projected distance of a binocularly presented virtual object changes as the observer converges and diverges. A model of eye and stimulus position illustrates that if an observer converges toward a binocular virtual stimulus that is fixed on the display, the projected stimulus will shift outward away from the observer. Conversely, if the observer diverges toward a binocular virtual stimulus that is fixed on the display, the projected stimulus will shift inward. For example, if an observer diverges from 25 cm to 300 cm, a binocular virtual stimulus projected at 300 cm will shift inward to 241 cm. Accurate depiction of a fixed stimulus distance in a binocular display requires that the stimulus position on the display surface should be adjusted in real- time to compensate for the observer's eye movements.

  9. Visual Stability of Objects and Environments Viewed through Head-Mounted Displays

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Adelstein, Bernard D.

    2015-01-01

    Virtual Environments (aka Virtual Reality) is again catching the public imagination and a number of startups (e.g. Oculus) and even not-so-startup companies (e.g. Microsoft) are trying to develop display systems to capitalize on this renewed interest. All acknowledge that this time they will get it right by providing the required dynamic fidelity, visual quality, and interesting content for the concept of VR to take off and change the world in ways it failed to do so in past incarnations. Some of the surprisingly long historical background of the technology that the form of direct simulation that underlies virtual environment and augmented reality displays will be briefly reviewed. An example of a mid 1990's augmented reality display system with good dynamic performance from our lab will be used to illustrate some of the underlying phenomena and technology concerning visual stability of virtual environments and objects during movement. In conclusion some idealized performance characteristics for a reference system will be proposed. Interestingly, many systems more or less on the market now may actually meet many of these proposed technical requirements. This observation leads to the conclusion that the current success of the IT firms trying to commercialize the technology will depend on the hidden costs of using the systems as well as the development of interesting and compelling content.

  10. A stochastic analysis of the calibration problem for Augmented Reality systems with see-through head-mounted displays

    NASA Astrophysics Data System (ADS)

    Leebmann, Johannes

    This paper presents a closed stochastic solution for the calibration of see-through head-mounted displays (STHMD) for Augmented Reality. An Augmented Reality system (ARS) is based on several components that are affected by stochastic and random errors. One important component is the tracking system. The flock of birds (FOB) tracking system was tested for consistency in position and orientation outputs by establishing constraints that the system was required to meet. The tests for position and orientation were separated to derive uncorrelated quality measures. The tests are self-controlling and do not require any other measuring device. In addition, the image coordinate accuracy also had to be determined to complete the stochastic description of the calibration problem. Based on this stochastic model, different mathematical models were tested to determine whether or not they fit the stochastic model. An overview of different calibration approaches for optical see-through displays is given and a quantitative comparison of the different models is made based on the derived accuracy information.

  11. Towards Intelligent Environments: An Augmented Reality–Brain–Machine Interface Operated with a See-Through Head-Mount Display

    PubMed Central

    Takano, Kouji; Hata, Naoki; Kansaku, Kenji

    2011-01-01

    The brain–machine interface (BMI) or brain–computer interface is a new interface technology that uses neurophysiological signals from the brain to control external machines or computers. This technology is expected to support daily activities, especially for persons with disabilities. To expand the range of activities enabled by this type of interface, here, we added augmented reality (AR) to a P300-based BMI. In this new system, we used a see-through head-mount display (HMD) to create control panels with flicker visual stimuli to support the user in areas close to controllable devices. When the attached camera detects an AR marker, the position and orientation of the marker are calculated, and the control panel for the pre-assigned appliance is created by the AR system and superimposed on the HMD. The participants were required to control system-compatible devices, and they successfully operated them without significant training. Online performance with the HMD was not different from that using an LCD monitor. Posterior and lateral (right or left) channel selections contributed to operation of the AR–BMI with both the HMD and LCD monitor. Our results indicate that AR–BMI systems operated with a see-through HMD may be useful in building advanced intelligent environments. PMID:21541307

  12. Towards intelligent environments: an augmented reality-brain-machine interface operated with a see-through head-mount display.

    PubMed

    Takano, Kouji; Hata, Naoki; Kansaku, Kenji

    2011-01-01

    The brain-machine interface (BMI) or brain-computer interface is a new interface technology that uses neurophysiological signals from the brain to control external machines or computers. This technology is expected to support daily activities, especially for persons with disabilities. To expand the range of activities enabled by this type of interface, here, we added augmented reality (AR) to a P300-based BMI. In this new system, we used a see-through head-mount display (HMD) to create control panels with flicker visual stimuli to support the user in areas close to controllable devices. When the attached camera detects an AR marker, the position and orientation of the marker are calculated, and the control panel for the pre-assigned appliance is created by the AR system and superimposed on the HMD. The participants were required to control system-compatible devices, and they successfully operated them without significant training. Online performance with the HMD was not different from that using an LCD monitor. Posterior and lateral (right or left) channel selections contributed to operation of the AR-BMI with both the HMD and LCD monitor. Our results indicate that AR-BMI systems operated with a see-through HMD may be useful in building advanced intelligent environments. PMID:21541307

  13. Development of a miniaturized system for monitoring vergence during viewing of stereoscopic imagery using a head-mounted display

    NASA Astrophysics Data System (ADS)

    Ames, Shelly L.; McBrien, Neville A.

    2004-05-01

    Head-mounted displays (HMDs) are popular for viewing stereoscopic imagery due of their immersive qualities. However, symptoms and visual problems are commonly associated with their use. The discrepancy between vergence and accommodation cues, present in stereoscopic imagery, has been implicated in these adverse effects. The aim of this investigation was to develop a high resolution but relatively inexpensive on-line vergence monitoring system for use within a HMD to enable important information about the vergence response to be obtained. The new vergence monitoring system utilized infrared (IR) light emitting diodes (LEDs) for illumination and miniature charge couple infrared (CCIR) cameras, one for each eye, to capture images of the eyes. The infrared light reflected from the eyes was directed to the cameras via cube beam splitters which allowed an uninterrupted line of sight to the HMD screens. An image acquisition board was used to capture the images and a program was designed using LabVIEW to process the images. The resolution was at least 0.2 degrees, which translates to vergence changes of 7 cm from the image plane of the V6 HMD. The vergence monitoring system enables a better understanding of the contribution of accommodation and vergence mismatch to symptoms and visual problems associated with viewing stereoscopic imagery.

  14. Assessment of visual space recognition of patients with unilateral spatial neglect and visual field defects using a head mounted display system

    PubMed Central

    Sugihara, Shunichi; Tanaka, Toshiaki; Miyasaka, Tomoya; Izumi, Takashi; Shimizu, Koichi

    2016-01-01

    [Purpose] The purpose of this study was the development of a method for presenting diverse visual information and assessing visual space recognition using a new head mounted display (HMD) system. [Subjects] Eight patients: four with unilateral spatial neglect (USN) and four with visual field defects (VFD). [Methods] A test sheet was placed on a desk, and its image was projected on the display of the HMD. Then, space recognition assessment was conducted using a cancellation test and motion analysis of the eyeballs and head under four conditions with images reduced in size and shifted. [Results] Leftward visual search was dominant in VFD patients, while rightward visual search was dominant in USN patients. The angular velocity of leftward eye movement during visual search of the right sheet decreased in both patient types. Motion analysis revealed a tendency of VFD patients to rotate the head in the affected direction under the left reduction condition, whereas USN patients rotated it in the opposite direction of the neglect. [Conclusion] A new HMD system was developed for presenting diverse visual information and assessing visual space recognition which identified the differences in the disturbance of visual space recognition of VFD and USN patients were indicated. PMID:27065515

  15. Assessment of visual space recognition of patients with unilateral spatial neglect and visual field defects using a head mounted display system.

    PubMed

    Sugihara, Shunichi; Tanaka, Toshiaki; Miyasaka, Tomoya; Izumi, Takashi; Shimizu, Koichi

    2016-01-01

    [Purpose] The purpose of this study was the development of a method for presenting diverse visual information and assessing visual space recognition using a new head mounted display (HMD) system. [Subjects] Eight patients: four with unilateral spatial neglect (USN) and four with visual field defects (VFD). [Methods] A test sheet was placed on a desk, and its image was projected on the display of the HMD. Then, space recognition assessment was conducted using a cancellation test and motion analysis of the eyeballs and head under four conditions with images reduced in size and shifted. [Results] Leftward visual search was dominant in VFD patients, while rightward visual search was dominant in USN patients. The angular velocity of leftward eye movement during visual search of the right sheet decreased in both patient types. Motion analysis revealed a tendency of VFD patients to rotate the head in the affected direction under the left reduction condition, whereas USN patients rotated it in the opposite direction of the neglect. [Conclusion] A new HMD system was developed for presenting diverse visual information and assessing visual space recognition which identified the differences in the disturbance of visual space recognition of VFD and USN patients were indicated.

  16. Effects of Configuration of Optical Combiner on Near-Field Depth Perception in Optical See-Through Head-Mounted Displays.

    PubMed

    Lee, Sangyoon; Hua, Hong

    2016-04-01

    The ray-shift phenomenon means the apparent distance shift in the display image plane between virtual and physical objects. It is caused by the difference in the refraction of virtual display and see-through optical paths derived from optical combiners that are necessary to provide a see-through capability in optical see-through head-mounted displays. In this work, through a human-subject experiment, we investigated the effects of ray-shift phenomenon induced by the optical combiner on depth perception for near-field distances (40 cm-100 cm). In our experiment, we considered three different configurations of optical combiner: horizontal-tilt and vertical-tilt configurations (using plate beamsplitters horizontally and vertically tilted by 45°, respectively), and non-tilt configuration (using rectangular solid waveguides). Participants' depth perception errors in these configurations were compared with those in an ordinary condition (i.e., the condition where physical objects are directly shown without the displays) and theoretically estimated ones. According to the experimental results, the measured percentage depth perception errors were similar to the theoretically estimated ones, where the amount of estimated percentage depth errors was greater than 0.3%. Furthermore, the participants showed significantly larger depth perception errors in the horizontal-tilt configuration than in an ordinary condition, while no large errors were found in the vertical-tilt configuration. In the non-tilt configuration, the results were dependent on the thickness of optical combiner and target distance.

  17. Helmet-Mounted Display Design Guide

    NASA Technical Reports Server (NTRS)

    Newman, Richard L.; Greeley, Kevin W.

    1997-01-01

    Helmet Mounted Displays (HMDs) present flight, navigation, and weapon information in the pilot's line of sight. The HMD was developed to allow the pilot to retain aircraft and weapon information while looking off boresight. This document reviews current state of the art in HMDs and presents a design guide for the HMD engineer in identifying several critical HMD issues: symbol stabilization, inadequate definitions, undefined symbol drive laws, helmet considerations, and Field Of View (FOV) vs. resolution tradeoff requirements. In particular, display latency is a key issue for HMDs. In addition to requiring further experimental studies, it impacts the definition and control law issues. Symbol stabilization is also critical. In the case of the Apache helicopter, the lack of compensation for pilot head motion creates excessive workload during hovering and Nap Of the Earth (NOE) flight. This translates into excessive training requirements. There is no agreed upon set of definitions or descriptions for how HMD symbols are driven to compensate for pilot head motion. A set of definitions is proposed to address this. There are several specific areas where simulation and flight experiments are needed: development of hover and NOE symbologies which compensate for pilot head movement; display latency and sampling, and the tradeoff between FOV, sensor resolution and symbology.

  18. Automatic calibration of an optical see-through head-mounted display for augmented reality applications in computer-assisted interventions

    NASA Astrophysics Data System (ADS)

    Figl, Michael; Ede, Christopher; Birkfellner, Wolfgang; Hummel, Johann; Seemann, Rudolf; Bergmann, Helmar

    2004-05-01

    We are developing an optical see through head mounted display in which preoperative planning data provided by a computer aided surgery system is overlaid to the optical image of the patient. In order to cope with head movements of the surgeon the device has to be calibrated for a wide zoom and focus range. For such a calibration accurate and robust localization of a huge amount of calibration points is of utmost importance. Because of the negligible radial distortion of the optics in our device, we were able to use projective invariants for stable detection of the calibration fiducials on a planar grid. The pattern at the planar grid was designed using a different cross ratio for four consecutive points in x respectively y direction. For automated image processing we put a CCD camera behind the eye piece of the device. The resulting image was thresholded and segmented, after deleting the artefacts a Sobel edge detector was applied and the image was Hough transformed to detect the x and y axes. Then the world coordinates of fiducial points on the grid could be detected. A series of six camera calibrations with two zoom settings was done. The mean values of the errors for the two calibrations were 0.08 mm respectively 0.3 mm.

  19. Raster graphic helmet-mounted display study

    NASA Technical Reports Server (NTRS)

    Beamon, William S.; Moran, Susanna I.

    1990-01-01

    A design of a helmet mounted display system is presented, including a design specification and development plan for the selected design approach. The requirements for the helmet mounted display system and a survey of applicable technologies are presented. Three helmet display concepts are then described which utilize lasers, liquid crystal display's (LCD's), and subminiature cathode ray tubes (CRT's), respectively. The laser approach is further developed in a design specification and a development plan.

  20. A hybrid simulated method for analyzing the optical efficiency of a head-mounted display with a quasi-crystal OLED panel.

    PubMed

    Chang, Kao-Der; Li, Chang-Yi; Pan, Jui-Wen; Cheng, Kuei-Yuan

    2014-03-10

    Organic light emitting diodes (OLEDs) with a quasi-crystal (QC) structure are analyzed and applied in a head-mounted display (HMD) system in this study. We adopt a hybrid simulated method to evaluate the light extraction efficiency (LEE) and far-field pattern in the air, and study the relationship between them. The simulation results show that OLEDs implanted with the QC structure can provide a collimated far-field pattern to increase the brightness. Using this 10-fold QC arrangement the maxima LEE of the OLEDs can be increased by 1.20 times. Compared with conventional OLEDs, the viewing angle of the OLED panel decreases from 120 degrees to 26 degrees with an improvement in the optical efficiency of the HMD system by 2.66 times. Moreover, the normalized on-axis intensity in the pupil of the eyepiece can be enlarged up to 3.95 times which suggests that the OLED panel can save 74.68% energy while achieving the same on-axis intensity as conventional OLEDs.

  1. Using a three-dimension head mounted displayer in audio-visual sexual stimulation aids in differential diagnosis of psychogenic from organic erectile dysfunction.

    PubMed

    Moon, K-H; Song, P-H; Park, T-C

    2005-01-01

    We designed this study to compare the efficacy of using a three-dimension head mounted displayer (3-D HMD) and a conventional monitor in audio-visual sexual stimulation (AVSS) in differential diagnosis of psychogenic from organic erectile dysfunction (ED). Three groups of subjects such as psychogenic ED, organic ED, and healthy control received the evaluation. The change of penile tumescence in AVSS was monitored with Nocturnal Electrobioimpedance Volumetric Assessment and sexual arousal after AVSS was assessed by a simple question as being good, fair, or poor. Both the group of healthy control and psychogenic ED demonstrated a significantly higher rate of normal response in penile tumescence (P<0.05) and a significantly higher level of sexual arousal (P<0.05) if stimulated with 3-D HMD than conventional monitor. In the group of organic ED, even using 3-D HMD in AVSS could not give rise to a better response in both assessments. Therefore, we conclude that using a 3-D HMD in AVSS helps more to differentiate psychogenic from organic ED than a conventional monitor in AVSS.

  2. Metamorphism in potential function while maintaining upright posture during exposure to a three-dimensional movie on an head-mounted display.

    PubMed

    Takada, Hiroki; Fujikake, Kazuhiro; Miyao, Masaru

    2009-01-01

    We propose a new index, sparse density (SPD), of stationary stabilograms for detecting the metamorphism in the (temporally averaged) potential function of stochastic differential equations, which occurs when a human attempts to maintain an upright posture. It is known that a mathematical model of the body sway can be developed by a stochastic process. The authors have succeeded in finding the nonlinearity in the potential function. In this study, subjects in a standing position were stimulated by three-dimensional (3-D) movies on an head-mounted display (HMD). We also measured the degree of determinism in the dynamics of the sway of the center of gravity of the subjects. The Double-Wayland algorithm was used as a novel method. As a result, the dynamics of the body sway in the presence of the stimulus as well as in its absence were considered to be stochastic. The metamorphism in the potential function during exposure to the conventional 3-D images could be detected by using the SPD.

  3. Metamorphism in potential function while maintaining upright posture during exposure to a three-dimensional movie on an head-mounted display.

    PubMed

    Takada, Hiroki; Fujikake, Kazuhiro; Miyao, Masaru

    2009-01-01

    We propose a new index, sparse density (SPD), of stationary stabilograms for detecting the metamorphism in the (temporally averaged) potential function of stochastic differential equations, which occurs when a human attempts to maintain an upright posture. It is known that a mathematical model of the body sway can be developed by a stochastic process. The authors have succeeded in finding the nonlinearity in the potential function. In this study, subjects in a standing position were stimulated by three-dimensional (3-D) movies on an head-mounted display (HMD). We also measured the degree of determinism in the dynamics of the sway of the center of gravity of the subjects. The Double-Wayland algorithm was used as a novel method. As a result, the dynamics of the body sway in the presence of the stimulus as well as in its absence were considered to be stochastic. The metamorphism in the potential function during exposure to the conventional 3-D images could be detected by using the SPD. PMID:19963636

  4. Holographic Helmet-Mounted Display Unit

    NASA Technical Reports Server (NTRS)

    Burley, James R., II; Larussa, Joseph A.

    1995-01-01

    Helmet-mounted display unit designed for use in testing innovative concepts for display of information to aircraft pilots. Operates in conjunction with computers generating graphical displays. Includes two ocular subunits containing miniature cathoderay tubes and optics providing 40 degrees vertical, 50 degrees horizontal field of view to each eye, with or without stereopsis. In future color application, each ocular subunit includes trichromatic holographic combiner tuned to red, green, and blue wavelengths of phosphors used in development of miniature color display devices.

  5. Helmet-mounted display (day/night)

    NASA Astrophysics Data System (ADS)

    Givens, Gerald S.; Yona, Zvi

    1996-06-01

    A dangerous situation is created when the pilot looks inside the cockpit for instrument information when flying combat and low altitude missions. While looking at instruments, a pilot cannot be performing situation analysis; yet not looking at instruments runs such risks as flying into the ground, particularly in low visibility conditions or in relatively featureless terrain where visual cues for altitude and attitude are inadequate or deceptive. The AN/AVS-7 HMD solves this problem for night flight for both helicopters and fixed wing aircraft which must operate in a 'nap of the earth' flight regime. The display unit mounts on the AN/AVS-6 night vision goggles and provides symbology overlaid on the pilot's outside view; cockpit instrument information is thus provided through the goggles. The pilot is immediately aware of changes in either his surroundings or the instrument readings. This minimizes the risk of critical information being missed in one area while the pilot is looking in the other. The 'day' HMD version of the AN/AVS-7 display now carries these advantages into daytime flights. This display unit operates in conditions from full sunlight to dusk, provides the same symbology as the night display, and connects to the night display interface with no aircraft modification. The day HMD mounts to the helmet using the attachment points previously reserved for the night vision goggles. This display improves the safety of daytime operations by keeping the eyes 'out of the cockpit' in difficult situations such as those presented during landings, cargo lifting and flight utilizing terrain masking. It offers the possibility of a less stressful way of familiarizing the pilot with the symbology and of the dynamic relationships it has to the aircraft and background motions. This familiarization is now accomplished during night flights using night vision goggles. The 'day' HMD is also a useful maintenance aid, easing the ground crew's checkout of the aircraft systems

  6. Integrated helmet mounted display concepts for air combat

    NASA Technical Reports Server (NTRS)

    Clark, Joseph W.

    1995-01-01

    A piloted simulation study was conducted in a dome simulator to evaluate several Helmet Mounted Display (HMD) formats developed as part of the NASA High Alpha Technology Program (HATP). The display formats conveyed energy management, spatial orientation, and weapons management information. The HMD format was compared to a generic Heads Up Display (HUD) typical of current operational fighter aircraft. Pilots were tasked to spend as much time in a weapon solution as possible, to have the correct weapon selected for the envelope they were in, and to avoid the adversary's weapon envelope as much as possible. Several different displays were tested individually and simultaneously to see how separate display concepts coexisted. Objective results showed that the ability for the pilot to select the correct weapon for the envelope he was in increased by 50% in a moderate workload condition and 90% in a high workload condition with the HMD format. In the post-test comments pilots generally favored the helmet display formats over the HUD formats with a few instances where pilots preferred a simple numeric readout of the parameter. Short term exposure effects of the HMD on visual acuity were also measured and showed no advers results.

  7. Comanche Helmet-Mounted Display Symbology Simulation

    NASA Technical Reports Server (NTRS)

    Turpin, Terry S.; Dowell, Susan R.; Szoboszlay, Zoltan

    2006-01-01

    The Aeroflightdynamics Directorate (AMRDEC) conducted a simulation to examine the performance of the Comanche Contact Analog world-referenced symbology displayed on the Comanche HIDSS when compared with a compressed symbology design similar to that specified by the former MIL-STD 1295. Six experimental test pilots flew one modified ADS-33 maneuver (hover turn, bob-up), an unusual attitude recovery, and two terrain flight tactical tasks in the NASA Vertical Motion Simulator (VMS). Analysis of the pilot objective performance data and subjective data showed the following results. Objective test results showed that 1295 symbology yielded more rapid maneuvering in the hover turn bob-up than Contact Analog symbology. The average margin of difference in the time to complete the maneuver was approximately two seconds, which was statistically significant. There were no significant differences measured between symbology sets with respect to altitude or position performance measures for all other maneuvers. The NOE target ID task data showed improved accuracy in determining heading to target when using Contact Analog over MIL-STD-1295. Subjective test results, including handling qualities ratings (HQRs) and NASA-TLX workload ratings, showed small but consistent advantages of 1295 symbology over Contact Analog for most parameters. For the bob-up maneuver, 1295 symbology handling qualities were rated Desired for lateral position error and time to complete whereas Contact Analog was rated adequate. The average HQRs for all other maneuvers were rated the same for both symbology sets. Pilot comments and the results of an online questionnaire more strongly favored 1295 over Contact Analog. Repeated comments from all six pilots led to a focus on design issues with six Contact Analog symbols. Those symbols were the heading tape, horizon line, radar altitude six-second predictor, the position of the torque symbol, the absence of a hover position cue, and the widespread positioning of

  8. Distance Perception of Stereoscopically Presented Virtual Objects Optically Superimposed on Physical Objects by a Head-Mounted See-Through Display

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Bucher, Urs J.; Statler, Irving C. (Technical Monitor)

    1994-01-01

    The influence of physically presented background stimuli on the perceived depth of optically overlaid, stereoscopic virtual images has been studied using headmounted stereoscopic, virtual image displays. These displays allow presentation of physically unrealizable stimulus combinations. Positioning of an opaque physical object either at the initial perceived depth of the virtual image or at a position substantially in front of the virtual image, causes the virtual image to perceptually move closer to the observer. In the case of objects positioned substantially in front of the virtual image, subjects often perceive the opaque object to become transparent. Evidence is presented that the apparent change of position caused by interposition of the physical object is not due to occlusion cues. According, it may have an alternative cause such as variation in the binocular vengeance position of the eyes caused by introduction of the physical object. This effect may complicate design of overlaid virtual image displays for near objects and appears to be related to the relative conspicuousness of the overlaid virtual image and the background. Consequently, it may be related to earlier analyses of John Foley which modeled open-loop pointing errors to stereoscopically presented points of light in terms of errors in determination of a reference point for interpretation of observed retinal disparities. Implications for the design of see-through displays for manufacturing will be discussed.

  9. Head-mounted spatial instruments: Synthetic reality or impossible dream

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Grunwald, Arthur; Velger, Mordekhai

    1988-01-01

    A spatial instrument is defined as a display device which has been either geometrically or symbolically enhanced to better enable a user to accomplish a particular task. Research conducted over the past several years on 3-D spatial instruments has shown that perspective displays, even when viewed from the correct viewpoint, are subject to systematic viewer biases. These biases interfere with correct spatial judgements of the presented pictorial information. It is also found that deliberate, appropriate geometric distortion of the perspective projection of an image can improve user performance. These two findings raise intriguing questions concerning the design of head-mounted spatial instruments. The design of such instruments may not only require the introduction of compensatory distortions to remove the neutrally occurring biases but also may significantly benefit from the introduction of artificial distortions which enhance performance. These image manipulations, however, can cause a loss of visual-vestibular coordination and induce motion sickness. Additionally, adaptation to these manipulations is apt to be impaired by computational delays in the image display. Consequently, the design of head-mounted spatial instruments will require an understanding of the tolerable limits of visual-vestibular discord.

  10. Cuff-Mounted Electronic Checklist Display Unit

    NASA Technical Reports Server (NTRS)

    Marmolejo, Jose A.; Fullerton, Richard; Cottingham, Paul; Chen, Chen-Hsiang; Shepherd, Charles

    1995-01-01

    Portable electronic display unit developed to provide text and pictures to guide users through complex technical procedures in field. Touch screen divided into six areas; touching each area causes display of specific menu or page, or activates electronic stopwatch. Unit strapped onto user's wrist in manner of wristwatch, leaving user's hands free to carry out procedures while referring to displayed information. Intended originally for use by astronaut in space suit, unit also eases tasks of technicians on Earth by providing quick and easy access to information, without need to carry and thumb through massive service manuals.

  11. A helmet mounted display to adapt the telerobotic environment to human vision

    NASA Technical Reports Server (NTRS)

    Tharp, Gregory; Liu, Andrew; Yamashita, Hitomi; Stark, Lawrence

    1990-01-01

    A Helmet Mounted Display system has been developed. It provides the capability to display stereo images with the viewpoint tied to subjects' head orientation. The type of display might be useful in a telerobotic environment provided the correct operating parameters are known. The effects of update frequency were tested using a 3D tracking task. The effects of blur were tested using both tracking and pick-and-place tasks. For both, researchers found that operator performance can be degraded if the correct parameters are not used. Researchers are also using the display to explore the use of head movements as part of gaze as subjects search their visual field for target objects.

  12. Using a Head-Mounted Camera to Infer Attention Direction

    ERIC Educational Resources Information Center

    Schmitow, Clara; Stenberg, Gunilla; Billard, Aude; von Hofsten, Claes

    2013-01-01

    A head-mounted camera was used to measure head direction. The camera was mounted to the forehead of 20 6- and 20 12-month-old infants while they watched an object held at 11 horizontal (-80° to + 80°) and 9 vertical (-48° to + 50°) positions. The results showed that the head always moved less than required to be on target. Below 30° in the…

  13. VISTA/NF-16D programmable helmet-mounted display system

    NASA Astrophysics Data System (ADS)

    Cameron, Alexander A.

    1997-06-01

    The VISTA/NV-16D is currently the newest in-flight simulator in the USAF inventory. This unique research aircraft will be fitted with the GEC-Marconi Avionics Programmable Display System. This equipment provides the capability to rapidly develop display concepts on both helmet-mounted display and head up displays in a dynamic flight test environment. The equipment provided includes an enhanced Viper II Helmet Mounted Display fitted to the HGU-86/P helmet. Display drive is provided by a very capable graphics generation system which also provides display drive to the standard F-16 Head Up Display. The system provides real time reprogrammable stroke and stroke on raster symbology on the HUD and on the HMD. The system is initially configured with monocular Stroke only HMD drive, but growth to dual HMD, stroke on video and binocular HMDs is available. The Honeywell Advanced Metal Tolerant Helmet Tracker System is integrated within the HMD Programmable Display System providing very accurate helmet orientation information to the graphics generator which is used for the display of space stabilized symbology when required. A fail safe backup display generator provides reversionary display on the HUD. This paper provides a detailed description of this equipment and also address some of the design techniques involved in developing this high performance system.

  14. Assessment of a head-mounted miniature monitor

    NASA Technical Reports Server (NTRS)

    Hale, J. P., II

    1992-01-01

    Two experiments were conducted to assess the capabilities and limitations of the Private Eye, a miniature, head-mounted monitor. The first experiment compared the Private Eye with a cathode ray tube (CRT) and hard copy in both a constrained and unconstrained work envelope. The task was a simulated maintenance and assembly task that required frequent reference to the displayed information. A main effect of presentation media indicated faster placement times using the CRT as compared with hard copy. There were no significant differences between the Private Eye and either the CRT or hard copy for identification, placement, or total task times. The goal of the second experiment was to determine the effects of various local visual parameters on the ability of the user to accurately perceive the information of the Private Eye. The task was an interactive video game. No significant performance differences were found under either bright or dark ambient illumination environments nor with either visually simple or complex task backgrounds. Glare reflected off of the bezel surrounding the monitor did degrade performance. It was concluded that this head-mounted, miniature monitor could serve a useful role for in situ operations, especially in microgravity environments.

  15. Performance effects of mounting a helmet-mounted display on the ANVIS mount of the HGU-56P helmet

    NASA Astrophysics Data System (ADS)

    Harding, Thomas H.; Martin, John S.; Rash, Clarence E.

    2006-05-01

    The U.S. Army, under the auspices of the Air Warrior Product Office, is developing a modular helmet-mounted display (HMD) for four aircraft series within its helicopter fleet. A design consideration is mounting the HMDs to the HGU- 56P Aviator's Night Vision Imaging System (ANVIS) mount. This particular mount is being considered, presumably due to its inherent cost savings, as the mount is already part of the helmet. Mounting the HMD in this position may have consequences for the daylight performance of these HMDs, as well as increasing the forward weight of the HMD. The latter would have consequences for helmet weight and center-of-mass biodynamic issues. Calculations were made of the increased luminance needed as a consequence of mounting the HMD in front of an HGU-56P tinted visor as opposed to mounting it behind the visor. By mounting in front of the helmet's visor, the HMD's light output will be filtered as light coming from the outside world. Special consideration then would have to be given to the HMD's light source selection process, as not to select a source that would differentially reduce luminance by a mounted visor (e.g., laser protection visors) compared to the ambient light in the aviator's field-of-view.

  16. Human factors issues in the design of helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Dudfield, Helen J.; Hardiman, Thomas D.; Selcon, Stephen J.

    1995-05-01

    The Head-Up Display (HUD) and Helmet Mounted Display (HMD) potentially offer the pilot several critical abilities: maintenance of head-out posture; enhanced situational awareness; real world target location and engagement; and provision of enhanced vision displays (e.g. FLIR). Experience with the HUD in current fast-jet cockpits has led to user acceptance and to the display of a wide range of information. Conversely, there is currently minimal experience of flight with HMDs and hence little is known of this technology on mission performance. Although the HMD has the benefit of cueing pilots as they move their head, it is unclear what the appropriate selection of stabilization cues should be, e.g. attitude information. This review considers a number of technological and psychological factors of which designers of HMDs should be aware.

  17. Helmet-Mounted Display Of Clouds Of Harmful Gases

    NASA Technical Reports Server (NTRS)

    Diner, Daniel B.; Barengoltz, Jack B.; Schober, Wayne R.

    1995-01-01

    Proposed helmet-mounted opto-electronic instrument provides real-time stereoscopic views of clouds of otherwise invisible toxic, explosive, and/or corrosive gas. Display semitransparent: images of clouds superimposed on scene ordinarily visible to wearer. Images give indications on sizes and concentrations of gas clouds and their locations in relation to other objects in scene. Instruments serve as safety devices for astronauts, emergency response crews, fire fighters, people cleaning up chemical spills, or anyone working near invisible hazardous gases. Similar instruments used as sensors in automated emergency response systems that activate safety equipment and emergency procedures. Both helmet-mounted and automated-sensor versions used at industrial sites, chemical plants, or anywhere dangerous and invisible or difficult-to-see gases present. In addition to helmet-mounted and automated-sensor versions, there could be hand-held version. In some industrial applications, desirable to mount instruments and use them similarly to parking-lot surveillance cameras.

  18. Helmet-Mounted Display Symbology and Stabilization Concepts

    NASA Technical Reports Server (NTRS)

    Newman, Richard L.

    1995-01-01

    The helmet-mounted display (HMD) presents flight, sensor, and weapon information in the pilot's line of sight. The HMD was developed to allow the pilot to retain aircraft and weapon information and to view sensor images while looking off boresight.

  19. Virtual display design using waveguide hologram in conical mounting configuration

    NASA Astrophysics Data System (ADS)

    Yan, Zhanjun; Li, Wenqiang; Zhou, Yongjun; Kang, Mingwu; Zheng, Zhenrong

    2011-09-01

    An improved virtual display is proposed by using a waveguide holographic configuration with two total internal reflection holographic gratings in conical mounting and two volume hologram in classical mounting recorded on a single transparent planar waveguide. Using this compact configuration, efficiency can be dramatically improved and assembly is easy to be realized. The main principle and the method of intensity uniformity control are present in the paper. The analysis and simulation results are also explained. The virtual display system design shows good optical performance with 25 deg. field of view, a large pupil about 43 mm, little distortion less than 1%, and low aberration. The configuration can be used to a portable or wearable display.

  20. Effects of localized auditory information on visual target detection performance using a helmet-mounted display.

    PubMed

    Nelson, W T; Hettinger, L J; Cunningham, J A; Brickman, B J; Haas, M W; McKinley, R L

    1998-09-01

    An experiment was conducted to evaluate the effects of localized auditory information on visual target detection performance. Visual targets were presented on either a wide field-of-view dome display or a helmet-mounted display and were accompanied by either localized, nonlocalized, or no auditory information. The addition of localized auditory information resulted in significant increases in target detection performance and significant reductions in workload ratings as compared with conditions in which auditory information was either nonlocalized or absent. Qualitative and quantitative analyses of participants' head motions revealed that the addition of localized auditory information resulted in extremely efficient and consistent search strategies. Implications for the development and design of multisensory virtual environments are discussed. Actual or potential applications of this research include the use of spatial auditory displays to augment visual information presented in helmet-mounted displays, thereby leading to increases in performance efficiency, reductions in physical and mental workload, and enhanced spatial awareness of objects in the environment.

  1. The effect of configural displays on pilot situation awareness in helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Jenkins, Joseph Christopher

    The current research utilized configural displays within the domain of aviation to assess what design features of configural displays contribute to the formation of operator situation awareness (SA). Configural displays map system information relevant to operator goals onto geometric shapes called emergent features. An emergent feature is formed from the combination of individual line segments to produce a global feature more perceptually salient and recognized sooner than the individual parts themselves. Configural displays have been shown in previous research to provide better operator performance for integration tasks where multiple pieces of information must be considered at once, yet the design aspects of configural displays that impact the formation of operator SA have yet to be determined. The current research compared the design features of three aviation configural displays over four experiments to quantify what aspects of configural displays would impact operator SA. The research sought to determine whether the simple act of representing system information in configural displays using emergent features is sufficient for facilitating operator SA or do other design factors need to be considered? Operator SA was assessed using explicit and implicit measures of SA from operator task performance in addition to a subjective SA rating scale. The recognition of aircraft attitude (climb/dive flight angles) when briefly presented to pilots in Experiment 1 revealed significant performance differences for the Arc Segment Attitude Reference (ASAR) configural display which mapped aircraft attitude information onto a circular shape versus the traditional aircraft head-up display (HUD) ladder found in the Joint Strike Fighter (JSF) HUD and Dual-Articulated (DA) HUD. The current research in Experiment 1 provides evidence that configural displays such as the ASAR that utilize emergent features well mapped to fully relate the information needed for a task will facilitate

  2. Operational utility evaluation of helmet-mounted trackers and displays (HMT/Ds)

    NASA Astrophysics Data System (ADS)

    Brown, Randall W.; Franck, Douglas L.

    1998-08-01

    Current Air Force aircraft, such as the F-15 and F-16, and future aircraft, have a need to leverage improving technologies such as helmet-mounted trackers and displays (HMT/Ds) to maintain superior air combat capability in future conflicts. HMT/Ds can allow the pilot to point weapons and to quickly slew sensors at short visual range targets in either an air-to-air or air-to-ground environment. Flight and weapons parameters commonly displayed on ahead-up display can be provided on HMT/Ds, allowing the pilot to remain 'head out' of the cockpit for longer time periods while maintaining better situational awareness. If the hMT/D systems are designed and then tested early, the result can then be used to transfer technology, and reduce risk, for follow-on programs such as the Joint Helmet-Mounted Cueing System.

  3. A review of head-worn display research at NASA Langley Research Center

    NASA Astrophysics Data System (ADS)

    Arthur, Jarvis J.; Bailey, Randall E.; Williams, Steven P.; Prinzel, Lawrence J.; Shelton, Kevin J.; Jones, Denise R.; Houston, Vincent

    2015-05-01

    NASA Langley has conducted research in the area of helmet-mounted/head-worn displays over the past 30 years. Initially, NASA Langley's research focused on military applications, but recently has conducted a line of research in the area of head-worn displays for commercial and business aircraft. This work has revolved around numerous simulation experiments as well as flight tests to develop technology and data for industry and regulatory guidance. The paper summarizes the results of NASA's helmet-mounted/head-worn display research. Of note, the work tracks progress in wearable collimated optics, head tracking, latency reduction, and weight. The research lends credence that a small, sunglasses-type form factor of the head-worn display would be acceptable to commercial pilots, and this goal is now becoming technologically feasible. The research further suggests that a head-worn display may serve as an "equivalent" Head-Up Display (HUD) with safety, operational, and cost benefits. "HUD equivalence" appears to be the economic avenue by which head-worn displays can become main-stream on the commercial and business aircraft flight deck. If this happens, NASA's research suggests that additional operational benefits using the unique capabilities of the head-worn display can open up new operational paradigms.

  4. A Review of Head-Worn Display Research at NASA Langley Research Center

    NASA Technical Reports Server (NTRS)

    Arthur, Jarvis (Trey) J., III; Bailey, Randall E.; Williams, Steven P.; Prinzel, Lawrence J., III; Shelton, Kevin J.; Jones, Denise R.; Houston, Vincent

    2015-01-01

    NASA Langley has conducted research in the area of helmet-mounted/head-worn displays over the past 30 years. Initially, NASA Langley's research focused on military applications, but recently it has conducted a line of research in the area of head-worn displays for commercial and business aircraft. This work has revolved around numerous simulation experiments as well as flight tests to develop technology and data for industry and regulatory guidance. The paper summarizes the results of NASA's helmet-mounted/head-worn display research. Of note, the work tracks progress in wearable collimated optics, head tracking, latency reduction, and weight. The research lends credence that a small, sunglasses-type form factor of the head-worn display would be acceptable to commercial pilots, and this goal is now becoming technologically feasible. The research further suggests that a head-worn display may serve as an "equivalent" Head-Up Display (HUD) with safety, operational, and cost benefits. "HUD equivalence" appears to be the economic avenue by which head-worn displays can become main-stream on the commercial and business aircraft flight deck. If this happens, NASA's research suggests that additional operational benefits using the unique capabilities of the head-worn display can open up new operational paradigms.

  5. Effects of lasers on helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Franck, Douglas L.; Kang, Robert N.

    1999-07-01

    The use of Helmet-Mounted Displays (HMD) and lasers is becoming widespread throughout the world. The Air Force Research Laboratory (AFRL) Helmet-Mounted Sensory Technologies (HMST) program is currently studying the effects incorporating the various laser eye protection (LEP) technologies into HMD technologies. LEP technologies currently available are absorptive organic dyes or reflective filters such as holograms or dielectric stacks. Because of the overall reduction in light transmittance and selective spectral filtering characteristics of various LEP technologies, compatibility with HMD technologies, and, ultimately, aircrew acceptance must be addressed. This paper will discuss some of the HMST requirements needed to perform adequate LEP and maintain HMD performance. This paper will also include a review of different approaches being studied to meet those requirements.

  6. South Fork Latrine, interior showing head with steel tank mounted ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    South Fork Latrine, interior showing head with steel tank mounted to wall; view south - Fort McKinley, South Fork Latrine, West side of East Side Drive, approximately 225 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

  7. Head-Up Displays and Attention Capture

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Risser, Matthew

    2004-01-01

    The primary role of head-up displays (HUDs) is to provide primary flight, navigation, and guidance information to the pilot in a forward field-of-view on a head-up transparent screen. Therefore, this theoretically allows for optimal control of an aircraft through the simultaneous scanning of both instrument data and the out-the-window scene. However, despite significant aviation safety benefits afforded by HUDs, a number of accidents have shown that their use does not come without costs. The human factors community has identified significant issues related to the pilot distribution of near and far domain attentional resources because of the compellingness of symbology elements on the HUD; a concern termed, attention or cognitive capture. The paper describes the phenomena of attention capture and presents a selected survey of the literature on the etiology and potential prescriptions.

  8. Solutions to helmet-mounted display visual correction compatibility issues

    NASA Astrophysics Data System (ADS)

    Rash, Clarence E.; Kalich, Melvyn E.; van de Pol, Corina

    2002-08-01

    To meet the goal of 24-hour, all-weather operation, U.S. Army aviation uses a number of imaging sensor systems on its aircraft. Imagery provided by these systems is presented on helmet-mounted displays (HMDs). Fielded systems include the Integrated Helmet Display Sighting System (IHADSS) used on the AH-64 Apache. Proposed future HMD systems such as the Helmet Integrated Display Sighting System (HIDSS) and the Microvision, Inc., Aircrew Integrated Helmet System (AIHS) scanning laser system are possible choices for the Army's RAH-66 Comanche helicopter. Ever present in current and future HMD systems is the incompatibility problem between the design-limited physical eye relief of the HMD and the need to provide for the integration of laser and nuclear, biological and chemical (NBC) protection, as well as the need to address the changing optical and vision requirements of the aging aviator. This paper defines the compatibility issue, reviews past efforts to solve this problem (e.g., contact lenses, NBC masks, optical inserts, etc.), and identifies emerging techniques (e.g., refractive surgery, adaptive optics, etc.) that require investigation.

  9. Helmet-Mounted Displays For Helicopter Pilotage: Design Configuration Tradeoffs, Analyses, And Test

    NASA Astrophysics Data System (ADS)

    Lohmann, Robert A.; Weisz, Alexander Z.

    1989-09-01

    Human engineering criteria applicable to the design of helmet mounted displays for use with night vision sensors, such as forward looking infra-red (FLIR) or low light level television (LLTV), are stated and reviewed. Systems requirements are presented which call for pilot operation at night that is as equivalent as practicable to flight under normal daytime visual rules. Requirements are developed that utilize head motion coupled to sensor movement to achieve the semblance of daytime pilotage while conducting operations at night under the cover of deep darkness. At the outset, salient factors are identified and prioritized which are applied to further design tradeoffs leading to helmet mounted visor displays. The prime design objectives being operational suitability, acceptability by the pilot community, reduced crew training requirements and minimal logistics support. In conclusion, alternate design configurations, computer analyses, operating experience, and pilot reaction are cited. Items to be addressed include: overall head supported weight, center-of-gravity, and other ergonomic factors affecting pilot acceptance: such as: comfort, eye-relief, total and instantaneous field of view, full or partial overlap of left-eye and right-eye fields of coverage, and head movement-to-sensor servo response. In addition, items of interest to the operating command: such as: training (ease or difficulty), maintenance of proficiency, and ease of viewing, will be discussed in light of data and operating experience from recently conducted flight trials. Finally, compatibility with nuclear biological and chemical (NBC) defense equipment and requirements, and laser eye protection will be discussed.

  10. Development and manufacture of visor for helmet-mounted display

    NASA Astrophysics Data System (ADS)

    Krevor, David H.; McNelly, Gregg; Skubon, John; Speirs, Robert

    2004-01-01

    The manufacturing design and process development for the Visor for the JHMCS (Joint Helmet Mounted Cueing System) are discussed. The JHMCS system is a Helmet Mounted Display (HMD) system currently flying on the F-15, F-16 and F/A-18 aircraft. The Visor manufacturing processes are essential to both system performance and economy. The Visor functions both as the system optical combiner and personal protective equipment for the pilot. The Visor material is optical polycarbonate. For a military HMD system, the mechanical and environmental properties of the Visor are as necessary as the optical properties. The visor must meet stringent dimensional requirements to assure adequate system optical performance. Injection molding can provide dimensional fidelity to the requirements, if done properly. Concurrent design of the visor and the tool (i.e., the injection mold) is essential. The concurrent design necessarily considers manufacturing operations and the use environment of the Visor. Computer modeling of the molding process is a necessary input to the mold design. With proper attention to product design and tool development, it is possible to improve upon published standard dimensional tolerances for molded polycarbonate articles.

  11. Quick-disconnect harness system for helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Bapu, P. T.; Aulds, M. J.; Fuchs, Steven P.; McCormick, David M.

    1992-10-01

    We have designed a pilot's harness-mounted, high voltage quick-disconnect connectors with 62 pins, to transmit voltages up to 13.5 kV and video signals with 70 MHz bandwidth, for a binocular helmet-mounted display system. It connects and disconnects with power off, and disconnects 'hot' without pilot intervention and without producing external sparks or exposing hot embers to the explosive cockpit environment. We have implemented a procedure in which the high voltage pins disconnect inside a hermetically-sealed unit before the physical separation of the connector. The 'hot' separation triggers a crowbar circuit in the high voltage power supplies for additional protection. Conductor locations and shields are designed to reduce capacitance in the circuit and avoid crosstalk among adjacent circuits. The quick- disconnect connector and wiring harness are human-engineered to ensure pilot safety and mobility. The connector backshell is equipped with two hybrid video amplifiers to improve the clarity of the video signals. Shielded wires and coaxial cables are molded as a multi-layered ribbon for maximum flexibility between the pilot's harness and helmet. Stiff cabling is provided between the quick-disconnect connector and the aircraft console to control behavior during seat ejection. The components of the system have been successfully tested for safety, performance, ergonomic considerations, and reliability.

  12. Manufacturing development of visor for binocular helmet mounted display

    NASA Astrophysics Data System (ADS)

    Krevor, David; Edwards, Timothy; Larkin, Eric; Skubon, John; Speirs, Robert; Sowden, Tom

    2007-09-01

    The HMD (Helmet Mounted Display) visor is a sophisticated article. It is both the optical combiner for the display and personal protective equipment for the pilot. The visor must have dimensional and optical tolerances commensurate with precision optics; and mechanical properties sufficient for a ballistic shield. Optimized processes and tooling are necessary in order to manufacture a functional visor. This paper describes the manufacturing development of the visor for the Joint Strike Fighter (JSF) HMD. The analytical and experimental basis for the tool and manufacturing process development are described; as well as the metrological and testing methods to verify the visor design and function. The requirements for the F-35 JSF visor are a generation beyond those for the HMD visor which currently flies on the F-15, F-16 and F/A-18. The need for greater precision is manifest in the requirements for the tooling and molding process for the visor. The visor is injection-molded optical polycarbonate, selected for its combination of optical, mechanical and environmental properties. Proper design and manufacture of the tool - the mold - is essential. Design of the manufacturing tooling is an iterative process between visor design, mold design, mechanical modeling and polymer-flow modeling. Iterative design and manufacture enable the mold designer to define a polymer shrinkage factor more precise than derived from modeling or recommended by the resin supplier.

  13. Eye Tracker Development On The Fiber Optic Helmet Mounted Display

    NASA Astrophysics Data System (ADS)

    Robinson, Richard M.; Thomas, Melvin L.; Wetzel, Paul A.

    1989-09-01

    To achieve the full potential of an area-of-interest (A0I) display requires that a high resolution area be accurately aligned with the direction of gaze. Two methods of eye position measurement with the Fiber Optic Helmet Mounted Display (FOHMD) have been developed and are described. This paper describes requirements necessary for successful eye tracking in aircraft simulators and introduces two approaches to monitoring eye position. In order to measure eye position over a wide field of view with sufficient accuracy, the oculometer must be able to measure various types of eye movements and also provide sufficient information to distinguish between eye movements and associated artifacts such as eye blinks and any anomalies introduced by spurious reflections or movement of the oculometer optics relative to the eye. In addition, the device must take into account variations in pupil size caused by changes in scene brightness and distinguish between pupil image displacements caused by actual eye movements or helmet slip. Under development are two oculometers that monitor both the center of the pupillary image and the corneal reflection and which possess both high temporal and spatial resolution.

  14. Perceptual issues for color helmet-mounted displays: luminance and color contrast requirements

    NASA Astrophysics Data System (ADS)

    Harding, Thomas H.; Rash, Clarence E.; Lattimore, Morris R.; Statz, Jonathan; Martin, John S.

    2016-05-01

    Color is one of the latest design characteristics of helmet-mounted displays (HMDs). It's inclusion in design specifications is based on two suppositions: 1) color provides an additional method of encoding information, and 2) color provides a more realistic, and hence more intuitive, presentation of information, especially pilotage imagery. To some degree, these two perceived advantages have been validated with head-down panel-mounted displays, although not without a few problems associated with visual physiology and perception. These problems become more prevalent when the user population expands beyond military aviators to a general user population, of which a significant portion may have color vision deficiencies. When color is implemented in HMDs, which are eyes-out, see-through displays, visual perception issues become an increased concern. A major confound with HMDs is their inherent see-through (transparent) property. The result is color in the displayed image combines with color from the outside (or in-cockpit) world, possibly producing a false perception of either or both images. While human-factors derived guidelines based on trial and error have been developed, color HMD systems still place more emphasis on colorimetric than perceptual standards. This paper identifies the luminance and color contrast requirements for see-through HMDs. Also included is a discussion of ambient scene metrics and the choice of symbology color.

  15. Helmet-mounted display technology on the VISTA NF-16D

    NASA Astrophysics Data System (ADS)

    Underhill, Gregory P.; Bailey, Randall E.; Markman, Steve

    1997-06-01

    Wright Laboratory's Variable-Stability In-Flight Simulator Test Aircraft (VISTA) NF-16D is the newest in-flight simulator in the USAF inventory. A unique research aircraft, it will perform a multitude of missions: to develop and evaluate flight characteristics of new aircraft that have not yet flown, and perform research in the areas of flying qualities, flight control design, pilot-vehicle interface, weapons and avionics integration, and to train new test pilots. The VISTA upgrade will enhance the simulation fidelity and research capabilities by adding a programmable helmet-mounted display (HMD) and head-up display (HUD) in the front cockpit. The programmable HMD consists of a GEC- Marconi Avionics Viper II Helmet-Mounted Optics Module integrated with a modified Helmet Integrated Systems Limited HGU-86/P helmet, the Honeywell Advanced Metal Tolerant tracker, and a GEC-Mounted Tolerant tracker, and a GEC- Marconi Avionics Programmable Display Generator. This system will provide a real-time programmable HUD and monocular stroke capable HMD in the front cockpit. The HMD system is designed for growth to stroke-on-video, binocular capability. This paper examines some of issues associated with current HMD development, and explains the value of rapid prototyping or 'quick-look' flight testing on the VISTA NF-16D. A brief overview of the VISTA NF-16D and the hardware and software modifications made to incorporate the programmable display system is give, as well as a review of several key decisions that were made in the programmable display system implementation. The system's capabilities and what they mean to potential users and designers are presented, particularly for pilot-vehicle interface research.

  16. MEMS scanned laser head-up display

    NASA Astrophysics Data System (ADS)

    Freeman, Mark O.

    2011-03-01

    Head-up displays (HUD) in automobiles and other vehicles have been shown to significantly reduce accident rates by keeping the driver's eyes on the road. The requirements for automotive HUDs are quite demanding especially in terms of brightness, dimming range, supplied power, and size. Scanned laser display technology is particularly well-suited to this application since the lasers can be very efficiently relayed to the driver's eyes. Additionally, the lasers are only turned on where the light is needed in the image. This helps to provide the required brightness while minimizing power and avoiding a background glow that disturbs the see-through experience. Microvision has developed a couple of HUD architectures that are presented herein. One design uses an exit pupil expander and relay optics to produce a high quality virtual image for built-in systems where the image appears to float above the hood of the auto. A second design uses a patented see-through screen technology and pico projector to make automotive HUDs available to anyone with a projector. The presentation will go over the basic designs for the two types of HUD and discuss design tradeoffs.

  17. Helmet-mounted displays for unmanned aerial vehicle control

    NASA Astrophysics Data System (ADS)

    Morphew, M. Ephimia; Shively, Jay R.; Casey, Daniel

    2004-09-01

    An experiment was performed to assess the effect of using a Helmet Mounted Display (HMD) versus a conventional computer monitor and joystick to perform an Unmanned Aerial Vehicle (UAV) sensor operator target search task. Eight subjects were evaluated on objective performance measures including their target detection accuracy and responses, in addition to subjective measures including workload, fatigue, situational awareness, and simulator sickness in both experimental conditions. Subjects were flown through a virtual world and asked to identify objects as targets, non-targets, or distractors. Results for objective measures indicated no difference in the operators' ability to accurately classify targets and non-targets. The subjects' ability to place the cursor on a target of interset (targeting accuracy), was, however, significantly better in the computer monitor condition than the HMD. The distance at which subjects could classify an object's identity was also significantly better in the computer monitor condition. Subjective measures showed no overall differences for sel-reported fatigue, workload, and situational awareness. A significant disadvantage, however, was found for the HMD with respect to self-reported nausea, disorientation, and oculomotor strain. Results are discussed in terms of their implications for the incorporation of HMDs into UAV ground control station operations.

  18. Near field magnetic communications for helmet-mounted display applications

    NASA Astrophysics Data System (ADS)

    Field, Mark; Sailer, Alan

    2005-05-01

    Helmet-mounted displays need a data feed that is typically provided by a cable or RF wireless data link to an external computer. In defense applications these solutions are problematic: a cable gets in the way and restricts use and emergency egress, while an RF wireless link can be detected at some distance giving away position and is susceptible to jamming. What is required is an alternative wireless technology that is low power, extremely localized and difficult to detect or jam. Near field magnetic communications is one possible alternative to RF communications that may fulfill these needs. This technology uses a time varying magnetic field to carry information, and is only useable over small distances of order six feet. This is expected to have significant advantages for particular applications: notably power requirements and security compared with RF wireless links. The power stored in a magnetic field falls off as 1/r6, compared with 1/r2 for RF, which means that all the power is localized around the transmitter. By having a physically small communications region around each platform or user, a large bandwidth can be guaranteed by allowing the reuse of the frequency spectrum outside the immediate vicinity. It also confers security on the data-link, as the signal is undetectable beyond the short range of the system.

  19. Cognitive issues in head-up displays

    NASA Technical Reports Server (NTRS)

    Fischer, E.; Haines, R. F.

    1980-01-01

    The ability of pilots to recognize and act upon unexpected information, presented in either the outside world or in a head-up display (HUD), was evaluated. Eight commercial airline pilots flew 18 approaches with a flightpath-type HUD and 13 approaches with conventional instruments in a fixed-base 727 simulator. The approaches were flown under conditions of low visibility, turbulence, and wind shear. Vertical and lateral flight performance was measured for five cognitive variables: an unexpected obstacle on runway; vertical and lateral boresight-type offset of the HUD; lateral ILS beam bend-type offset; and no anomaly. Mean response time to the runway obstacle was longer with HUD than without it (4.13 vs 1.75 sec.), and two of the pilots did not see the obstacle at all with the HUD. None of the offsets caused any deterioration in lateral flight performance, but all caused some change in vertical tracking; all offsets seemed to magnify the environmental effects. In all conditions, both vertical and lateral tracking was better with the HUD than with the conventional instruments.

  20. Attentional limitations with Head-Up Displays

    NASA Technical Reports Server (NTRS)

    Mccann, Robert S.; Foyle, David C.; Johnston, James C.

    1993-01-01

    Recent models of visual information processing suggest that visual attention can be focussed on either Head-Up Displays (HUD) or on the world beyond them, but not on both simultaneously. This hypothesis was tested in a part-task simulation in which subjects viewed a simulated approach to a runway with a HUD superimposed. An alphanumeric cue ('IFR' or 'VFR') appeared on either the HUD or the runway and was followed by two sets of three geometric forms; one set on the HUD and one set on the runway. Each set contained one potential target, either a stop sign or a diamond. If the cue spelled 'IFR', subjects made a speeded response based on the identity of the HUD target; if the cue spelled 'VFR', subjects made a speeded response based on the identity of the runway target. Regardless of cue location (HUD or Runway), responses were faster when the cue and the relevant target were part of the same perceptual group (i.e., both on the HUD or both on the runway) than when they were part of different perceptual groups. These results, as well as others, suggest that attentional constraints place severe limits on the ability of pilots to process HUD-referenced information and world-referenced information simultaneously. In addition, they provide direct evidence that transitioning from processing HUD information to processing world information requires an attention shift. Implications for HUD design are considered.

  1. Development of helmet-mounted display symbology for use as a primary flight reference

    NASA Astrophysics Data System (ADS)

    Jenkins, J. Chris

    2003-09-01

    The helmet-mounted display (HMD) will be used as the sole means of displaying head-up information to the pilot in future U.S. Air Force (USAF) fixed-wing tactical aircraft. For current fighter aircraft that employ the use of a stand-alone head-up display (HUD), the HMD will be integrated to provide the off-boresight symbology component of the head-up presentation. The symbology for on- and off-boresight use has to be designed to insure the effective interaction between display formats for conveyance of information to the pilot when transitioning between on- and off-boresight viewing angles. This is true for legacy aircraft where the symbology is presented in part by the HUD for on-boresight use with the HMD utilized for the off-boresight application and also for HUD-less aircraft, such as the Joint Strike Fighter, where symbology will be presented solely on the HMD. The Air Force Research Laboratory has been developing HMD symbology to meet the requirements to certify the HMD as a primary flight reference (PFR) for USAF fixed-wing tactical aircraft. This symbology has been designed to maximize the transference of attitude awareness to the pilot when switching between on- and off-boresight attitude references to help insure the pilot achieves correct awareness of spatial orientation. This paper describes the previous research that examined the ASAR for HUD applications, the design of the AFRL ASAR HUD symbology to replace the climb-dive ladder, and the planned flight test evaluation of the ASAR HUD for endorsement as a PFR.

  2. Hardware Improvements To The Helmet Mounted Projector On The Visual Display Research Tool (VDRT) At The Naval Training Systems Center

    NASA Astrophysics Data System (ADS)

    Burbidge, Richard; Murray, Paul M.

    1989-09-01

    The Visual Pisplay Research Tool includes a helmet mounted projector for the display of flight simulation Area-of-Interest imagery on a 10 foot radius dome. The imagery is transmitted to the helmet using two coherent fibre optic ribbons. Some improvements have been made to the fibre optic system and to the helmet fit. The imagery is head and eye slaved and the concepts for image positioning and stabilisation are described.

  3. Advanced rotorcraft helmet-mounted display sighting system (HMDSS) optical distortion correction methodology

    NASA Astrophysics Data System (ADS)

    Hebson, Robert T.; Lee, Louie

    2002-08-01

    Helmet Mounted Displays (HMDs) typically utilize off axis optical systems that result in distorted images. In order to minimize the weight on the pilot's head, a pixilated display, such as an Active Matrix liquid Crystal Display (AMLCD), is utilized as the imaging source. Pixelated displays based on AMLCDs cannot correct distortions or perform spatial transformations as easily as an analog CRT-based systems using electron beam deflection. An advanced rotorcraft HMDSS is a digital system where correcting the distortion within the digital domain is desired to eliminate the inaccuracies of converting to analog, correcting the distortion and converting back to digital. Other system requirements necessitate that the input video be rescaled to provide the proper image to the optical system in order to have the FLIR imagery overlay the real world as the pilot looks through the canopy. To optimize image resolution with minimum sensor size, the FLIR system scans in column mode. As this is not compatible with conventional AMLCD scanning, the FLIR video data must be converted to a row scan. This function, which normally results in additional frame delay, will also be described, together with methods for reducing the latency. The physical constrains of the helmet and the desire to use identical AMLCD devices meant that the devices are rotated between sides of the helmet. This rotation requires that the video image be scanned horizontally and vertically flipped creating another complexity in the design. Requirements for a helmet mounted image intensified television camera to be displayed as an image by itself or overlaid with symbology provided from external video creates additional complexity for distortion correction within the optical chain and will be discussed in this paper. All of these modes require that the video be manipulated in varying degrees of complexity. The enabling technology described in this paper is a complex integrated circuit that allows the user to

  4. Applications of Augmented Vision Head-Mounted Systems in Vision Rehabilitation

    PubMed Central

    Peli, Eli; Luo, Gang; Bowers, Alex; Rensing, Noa

    2007-01-01

    Vision loss typically affects either the wide peripheral vision (important for mobility), or central vision (important for seeing details). Traditional optical visual aids usually recover the lost visual function, but at a high cost for the remaining visual function. We have developed a novel concept of vision-multiplexing using augmented vision head-mounted display systems to address vision loss. Two applications are discussed in this paper. In the first, minified edge images from a head-mounted video camera are presented on a see-through display providing visual field expansion for people with peripheral vision loss, while still enabling the full resolution of the residual central vision to be maintained. The concept has been applied in daytime and nighttime devices. A series of studies suggested that the system could help with visual search, obstacle avoidance, and nighttime mobility. Subjects were positive in their ratings of device cosmetics and ergonomics. The second application is for people with central vision loss. Using an on-axis aligned camera and display system, central visibility is enhanced with 1:1 scale edge images, while still enabling the wide field of the unimpaired peripheral vision to be maintained. The registration error of the system was found to be low in laboratory testing. PMID:18172511

  5. Latency requirements for head-worn display S/EVS applications

    NASA Astrophysics Data System (ADS)

    Bailey, Randall E.; Arthur, Jarvis J., III; Williams, Steven P.

    2004-08-01

    NASA's Aviation Safety Program, Synthetic Vision Systems Project is conducting research in advanced flight deck concepts, such as Synthetic/Enhanced Vision Systems (S/EVS), for commercial and business aircraft. An emerging thrust in this activity is the development of spatially-integrated, large field-of-regard information display systems. Head-worn or helmet-mounted display systems are being proposed as one method in which to meet this objective. System delays or latencies inherent to spatially-integrated, head-worn displays critically influence the display utility, usability, and acceptability. Research results from three different, yet similar technical areas - flight control, flight simulation, and virtual reality - are collectively assembled in this paper to create a global perspective of delay or latency effects in head-worn or helmet-mounted display systems. Consistent definitions and measurement techniques are proposed herein for universal application and latency requirements for Head-Worn Display S/EVS applications are drafted. Future research areas are defined.

  6. Latency Requirements for Head-Worn Display S/EVS Applications

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Trey Arthur, J. J., III; Williams, Steven P.

    2004-01-01

    NASA s Aviation Safety Program, Synthetic Vision Systems Project is conducting research in advanced flight deck concepts, such as Synthetic/Enhanced Vision Systems (S/EVS), for commercial and business aircraft. An emerging thrust in this activity is the development of spatially-integrated, large field-of-regard information display systems. Head-worn or helmet-mounted display systems are being proposed as one method in which to meet this objective. System delays or latencies inherent to spatially-integrated, head-worn displays critically influence the display utility, usability, and acceptability. Research results from three different, yet similar technical areas flight control, flight simulation, and virtual reality are collectively assembled in this paper to create a global perspective of delay or latency effects in head-worn or helmet-mounted display systems. Consistent definitions and measurement techniques are proposed herein for universal application and latency requirements for Head-Worn Display S/EVS applications are drafted. Future research areas are defined.

  7. Human factors issues in the development of helmet-mounted displays for tactical fixed-wing aircraft

    NASA Astrophysics Data System (ADS)

    Barnaba, James M.

    1997-06-01

    There are many human factors issues that should be considered when designing a helmet mounted display for use in high speed aircraft with ejection seats. The Joint Helmet Mounted Cueing System Program Office, with support from the Armstrong Laboratory and the Naval Air Warfare Center, has been studying many of these issues and is able to report several findings in the areas of anthropometry, limitations in head movement, helmet stability under high gravity forces and mass properties. This paper serves to summarize the findings of the program office in these areas. The paper will include highlights of several studies that have involved anthropometric data manipulation, 3D head scans, and testing of manikin and human subjects in static and dynamic cockpit environment simulations.

  8. Flight performance using a hyperstereo helmet-mounted display: post-flight debriefing questionnaire

    NASA Astrophysics Data System (ADS)

    Kalich, Melvyn E.; Rash, Clarence E.; Harding, Thomas H.; Jennings, Sion; Craig, Gregory; Stuart, Geoffrey W.

    2009-05-01

    Helmet-mounted display (HMD) designs have faced persistent head-supported mass and center of mass (CM) problems, especially HMD designs like night vision goggles (NVG) that utilize image intensification (I2) sensors mounted forward in front of the user's eyes. Relocating I2 sensors from the front to the sides of the helmet, at or below the transverse plane through the user's head CM, can resolve most of the CM problems. However, the resulting increase in the separation between the two I2 channels effectively increases the user's interpupillary distance (IPD). This HMD design is referred to as a hyperstero design and introduces the phenomenon of hyperstereopsis, a type of visual distortion where stereoscopic depth perception is exaggerated, particularly at distances under 200 feet (~60 meters). The presence of hyperstereopsis has been a concern regarding implementation of hyperstereo HMDs for rotary-wing aircraft. To address this concern, a flight study was conducted to assess the impact of hyperstereopsis on aircraft handling proficiency and pilot acceptance. Three rated aviators with differing levels of I2 and hyperstereo HMD experience conducted a series of flights that concentrated on low-level maneuvers over a two-week period. Initial and final flights were flown with a standard issue I2 device and a production hyperstereo design HMD. Interim flights were flown only with the hyperstereo HMD. Two aviators accumulated 8 hours of flight time with the hyperstereo HMD, while the third accumulated 6.9 hours. This paper presents data collected via written questionnaires completed by the aviators during the post-flight debriefings. These data are compared to questionnaire data from a previous flight investigation in which aviators in a copilot capacity, hands not on the flight controls, accumulated 8 flight hours of flight time using a hyperstereo HMD.

  9. Head-mounted spatial instruments II: Synthetic reality or impossible dream

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Grunwald, Arthur

    1989-01-01

    A spatial instrument is defined as a spatial display which has been either geometrically or symbolically enhanced to enable a user to accomplish a particular task. Research conducted over the past several years on 3-D spatial instruments has shown that perspective displays, even when viewed from the correct viewpoint, are subject to systematic viewer biases. These biases interfere with correct spatial judgements of the presented pictorial information. The design of spatial instruments may not only require the introduction of compensatory distortions to remove the naturally occurring biases but also may significantly benefit from the introduction of artificial distortions which enhance performance. However, these image manipulations can cause a loss of visual-vestibular coordination and induce motion sickness. Consequently, the design of head-mounted spatial instruments will require an understanding of the tolerable limits of visual-vestibular discord.

  10. In-flight evaluation of a fiber optic helmet-mounted display

    NASA Astrophysics Data System (ADS)

    Jennings, Sion A.; Gubbels, Arthur W.; Swail, Carl P.; Craig, Greg

    1998-08-01

    The National Research Council of Canada (NRC), in conjunction with the Canadian Department of National Defence (DND), is investigating the use of helmet-mounted displays (HMD) to improve pilot situational awareness in all-weather search and rescue helicopter operations. The National Research Council has installed a visually coupled HMD system in the NRC Bell 205 Airborne Simulator. Equipped with a full authority fly-by-wire control system, the Bell 205 has variable stability characteristics, which makes the airborne simulator the ideal platform for the integrated flight testing of HMDs in a simulated operational environment. This paper presents preliminary results from flight test of the NRC HMD. These results are in the form of numerical head tracker data, and subjective handling qualities ratings. Flight test results showed that the HMD degraded handling qualities due to reduced acuity, limited field-of-view, time delays in the sensor platform, and fatigue caused by excessive helmet inertia. Some evidence was found to support the hypothesis of an opto-kinetic cervical reflex whereby a pilot pitches and rolls his head in response to aircraft movements to maintain a level horizon in their field-of- view.

  11. Effects of aircraft windscreen on helmet-mounted display/tracker aiming accuracy

    NASA Astrophysics Data System (ADS)

    Task, H. Lee

    1996-06-01

    Modern fighter aircraft windscreens are typically made of curved, transparent plastic for improved aero-dynamics and bird-strike protection. Since they are curved these transparencies often refract light in such a way that a pilot looking through the transparency will see a target in a location other than where it really is. This effect has been known for many years and methods to correct the aircraft head-up display (HUD) for these angular deviations have been developed and employed. The same problem will occur for helmet-mounted displays (HMDs) used for target acquisition only worse due to the fact the pilot can look through any part of the transparency instead of being constrained to just the forward section as in the case of the HUD. To determine the potential impact of these windscreen refraction errors two F-15 windscreens were measured; one acrylic and one multilayer acrylic and polycarbonate laminate. The average aiming error measured for the acrylic was 3.6 milliradians with a maximum error of 9.0 milliradians. The laminated windscreen was slightly worse at 4.1 milliradians average error and 10.5 milliradians maximum. These aiming errors were greatly reduced by employing correction algorithms which could be applied to the aiming information on the HMD. Subtleties of coordinate systems and roll correction are also addressed.

  12. Emergence of solid state helmet-mounted displays in military applications

    NASA Astrophysics Data System (ADS)

    Casey, Curtis J.

    2002-08-01

    Helmet Mounted Displays (HMDs) are used to provide pilots with out-the-window capabilities for engaging tactical threats. The first modern system to be employed was the Apache Integrated Helmet Display Sighting System (IHADSS). Using an optical tracker and multiple sensors, the pilot is able to navigate and engage the enemy with his weapons systems cued by the HMD in day and night conditions. Over the next several years HMDs were tested on tactical jet aircraft. The tactical fighter environment - high G maneuvering and the possibility of ejection - created several problems regarding integration and head-borne weight. However, these problems were soon solved by American, British, Israeli, and Russian companies and are employed or in the process of employment aboard the respective countries' tactical aircraft. It is noteworthy that the current configuration employs both the Heads-Up Display (HUD) as well as the HMD. The new Joint Strike Fighter (JSF), however, will become the first tactical jet to employ only a HMD. HMDs have increasingly become part of the avionics and weapons systems of new aircraft and helicopter platforms. Their use however, is migrating to other military applications. They are currently under evaluation on Combat Vehicle platforms for driving tasks to target acquisition and designation tasks under near-all weather, 24-hour conditions. Their use also has penetrated the individual application such as providing data and situational awareness to the individual soldier; the U.S. Army's Land Warrior Program is an example of this technology being applied. Current HMD systems are CRT-based and have many short-comings, including weight, reliability. The emergence of new microelectronics and solid state image sources - Flat Panel Displays (FPDs) - however, has expanded the application of vision devices across all facets of military applications. Some of the greatest contributions are derived from the following Enabling Technologies, and it is upon those

  13. Low-cost helmet-mounted camera/display system for field testing teleoperator tasks

    NASA Astrophysics Data System (ADS)

    Cole, Robert E.; Ikehara, Curtis S.; Merritt, John O.

    1992-06-01

    A low cost helmet-mounted stereoscopic color viewing system designed for field testing teleoperator tasks is described. A stereo camera pair was mounted on a helmet to allow testing of a helmet-mounted display with real time video input. The display consisted of a pair of LCD color monitors viewed through a modified Wheatstone mirror system. The components were arranged on a stable platform that was attached to a hard plastic helmet. The helmet weight (9.5 pounds) was supported by a modified backpack. This backpack also contained support electronics and batteries. Design, construction, and evaluation tests of this viewing system are discussed.

  14. The use of optical waveguides in head up display (HUD) applications

    NASA Astrophysics Data System (ADS)

    Homan, Malcolm

    2013-06-01

    The application of optical waveguides to Head Up Displays (HUD) is an enabling technology which solves the critical issues of volume reduction (including cockpit intrusion) and mass reduction in an affordable product which retains the high performance optical capabilities associated with today's generation of digital display based HUDs. Improved operability and pilot comfort is achieved regardless of the installation by virtue of the intrinsic properties of optical waveguides and this has enabled BAE Systems Electronic Systems to develop two distinct product streams for glareshield and overhead HUD installations respectively. This paper addresses the design drivers behind the development of the next generation of Head Up Displays and their compatibility with evolving cockpit architectures and structures. The implementation of large scale optical waveguide combiners capable of matching and exceeding the display performances normally only associated with current digital display sourced HUDs has enabled BAE Systems Electronic Systems to solve the volume and installation challenges of the latest military and civil cockpits with it's LiteHUD® technology. Glareshield mounted waveguide based HUDs are compatible with the trend towards the addition of Large Area Displays (LAD) in place of the traditional multiple Head Down Displays (HDD) within military fast jet cockpits. They use an "indirect view" variant of the display which allows the amalgamation of high resolution digital display devices with the inherently small volume and low mass of the waveguide optics. This is then viewed using the more traditional technology of a conventional HUD combiner. This successful combination of technologies has resulted in the LPHUD product which is specifically designed by BAE Systems Electronic Systems to provide an ultra-low profile HUD which can be installed behind a LAD; still providing the level of performance that is at least equivalent to that of a conventional large volume

  15. Remote vs. head-mounted eye-tracking: a comparison using radiologists reading mammograms

    NASA Astrophysics Data System (ADS)

    Mello-Thoms, Claudia; Gur, David

    2007-03-01

    Eye position monitoring has been used for decades in Radiology in order to determine how radiologists interpret medical images. Using these devices several discoveries about the perception/decision making process have been made, such as the importance of comparisons of perceived abnormalities with selected areas of the background, the likelihood that a true lesion will attract visual attention early in the reading process, and the finding that most misses attract prolonged visual dwell, often comparable to dwell in the location of reported lesions. However, eye position tracking is a cumbersome process, which often requires the observer to wear a helmet gear which contains the eye tracker per se and a magnetic head tracker, which allows for the computation of head position. Observers tend to complain of fatigue after wearing the gear for a prolonged time. Recently, with the advances made to remote eye-tracking, the use of head-mounted systems seemed destined to become a thing of the past. In this study we evaluated a remote eye tracking system, and compared it to a head-mounted system, as radiologists read a case set of one-view mammograms on a high-resolution display. We compared visual search parameters between the two systems, such as time to hit the location of the lesion for the first time, amount of dwell time in the location of the lesion, total time analyzing the image, etc. We also evaluated the observers' impressions of both systems, and what their perceptions were of the restrictions of each system.

  16. Flight test evaluation of the nondistributed flight reference off-boresight helmet-mounted display symbology

    NASA Astrophysics Data System (ADS)

    Jenkins, J. Chris; Thurling, Andrew J.; Havig, Paul R.; Geiselman, Eric E.

    2002-08-01

    The Air Force Research Laboratory (AFRL) has been working to optimize helmet-mounted display (HMD) symbology for off-boresight use. One candidate symbology is called the non-distributed flight reference (NDFR). NDFR symbology allows ownship status information to be directly referenced from the HMD regardless of pilot line of sight. The symbology is designed to aid pilot maintenance of aircraft state awareness during the performance of off-boresight tasks such as air-to-ground and air-to-air target acquisition. Previous HMD symbology research has shown that pilots spend longer periods of time off-boresight when using an HMD and therefore less time referencing primary displays in the aircraft cockpit. NDFR may provide needed information for the pilot to safely spend longer periods of search time off-boresight. Recently, NDFR was flight tested by the USAF Test Pilot School at Edwards AFB, CA, aboard the VISTA F-16 (Variable Stability In-flight Simulator Test Aircraft) during operationally representative air-to-air and air-to-ground tasks, as well as unusual attitude recoveries. The Mil-Std-1787B head-up display (HUD) symbology and another off-boresight HMD symbology called the Visually Coupled Acquisition and Targeting System (VCATS) were evaluated as comparison symbol sets. The results of the flight test indicate a clear performance advantage afforded by the use of off-boresight symbology compared to HUD use alone. There was a significant increase in the amount of time pilots looked off-boresight with both the NDFR and VCATS symbologies. With the NDFR, this increase was achieved without an associated primary task performance tradeoff. This was true for both air-to-ground and air-to-air tasks.

  17. Flight performance using a hyperstereo helmet-mounted display: aircraft handling

    NASA Astrophysics Data System (ADS)

    Jennings, Sion A.; Craig, Gregory L.; Stuart, Geoffrey W.; Kalich, Melvyn E.; Rash, Clarence E.; Harding, Thomas H.

    2009-05-01

    A flight study was conducted to assess the impact of hyperstereopsis on helicopter handling proficiency, workload and pilot acceptance. Three pilots with varying levels of night vision goggle and hyperstereo helmet-mounted display experience participated in the test. The pilots carried out a series of flights consisting of low-level maneuvers over a period of two weeks. Four of the test maneuvers, The turn around the tail, the hard surface landing, the hover height estimation and the tree-line following were analysed in detail. At the end of the testing period, no significant difference was observed in the performance data, between maneuvers performed with the TopOwl helmet and maneuvers performed with the standard night vision goggle. This study addressed only the image intensification display aspects of the TopOwl helmet system. The tests did not assess the added benefits of overlaid symbology or head slaved infrared camera imagery. These capabilities need to be taken into account when assessing the overall usefulness of the TopOwl system. Even so, this test showed that pilots can utilize the image intensification imagery displayed on the TopOwl to perform benign night flying tasks to an equivalent level as pilots using ANVIS. The study should be extended to investigate more dynamic and aggressive low level flying, slope landings and ship deck landings. While there may be concerns regarding the effect of hyperstereopsis on piloting, this initial study suggests that pilots can either adapt or compensate for hyperstereo effects with sufficient exposure and training. Further analysis and testing is required to determine the extent of training required.

  18. Exaggerated displays do not improve mounting success in male seaweed flies Fucellia tergina (Diptera: Anthomyiidae).

    PubMed

    Memmott, Ruth; Briffa, Mark

    2015-11-01

    Signals of individual quality are assumed to be difficult to exaggerate, either because they are directly linked to underlying traits (indices) or because they are costly to perform (handicaps). In practise advertisement displays may consist of conventional and costly components, for instance where a morphological structure related to body size is used in visual displays. In this case, there is the potential for dishonest displays, due to the population level variance around the relationship between body size and display structures. We examine the use of wing flicking displays that we observed in situ in a strandline dwelling seaweed fly Fucellia tergina, using overall body size and the size of their eyes as underlying indicators of condition. Males displayed far more frequently than females, and were also observed to frequently mount other flies, a behaviour that was rare in females. The rate of display was greater for males that had positive residual values from relationships between wing length and body length. In other words those males with larger than expected wings for their underlying quality displayed more frequently, indicating that these displays are open to exaggeration. Males with larger than expected wings (for the size of their body or eyes), however, mounted less frequently. We suggest that small bodied males are less successful in terms of mounting, but that those small males with relatively large wings may attempt to compensate for this through increased display effort.

  19. Challenges with displaying enhanced and synthetic vision video on a head-up display

    NASA Astrophysics Data System (ADS)

    Howells, Peter J.; Brown, Robert

    2007-04-01

    Displaying video on a head-up display from an Enhanced Vision System camera or Synthetic Vision System engine presents some unique challenges not seen on conventional head-down flight deck displays. All information displayed on the HUD has to be seen against a background that can vary from bright sunlight to a dark night sky. The video has to include enough grayshade information to support visual identification of runway features and the image shown on the HUD has to be visually aligned to the real world accurately enough to support low-visibility operations at airports. The pilot needs to clearly see the image on the HUD but also needs to see the real world through the display when it can be seen with the naked eye. In addition, the video display cannot interfere with the display of existing flight information symbology.

  20. Critical testing for helmet-mounted displays: a tracking system accuracy test for the joint helmet mounted cueing system

    NASA Astrophysics Data System (ADS)

    Renner, Adam P.

    2012-06-01

    Helmet mounted displays have not been supported with adequate methods and materials to validate and verify the performance of the underlying tracking systems when tested in a simulated or operational environment. Like most electronic systems on aircraft, HMDs evolve over the lifecycle of the system due to requirements changes or diminishing manufacturing sources. Hardware and software bugs are often introduced as the design evolves and it is necessary to revalidate a systems performance attributes over the course of these design changes. An on-aircraft test has been developed and refined to address this testing gap for the Joint Helmet Mounted Cueing System (JHMCS) on F-16 aircraft. This test can be readily ported to other aircraft systems which employ the JHMCS, and has already been ported to the F-18. Additionally, this test method could provide an added value in the testing of any HMD that requires accurate cueing, whether used on fixed or rotary wing aircraft.

  1. Computer-enhanced stereoscopic vision in a head-mounted operating binocular.

    PubMed

    Birkfellner, Wolfgang; Figl, Michael; Matula, Christian; Hummel, Johann; Hanel, Rudolf; Imhof, Herwig; Wanschitz, Felix; Wagner, Arne; Watzinger, Franz; Bergmann, Helmar

    2003-02-01

    Based on the Varioscope, a commercially available head-mounted operating binocular, we have developed the Varioscope AR, a see through head-mounted display (HMD) for augmented reality visualization that seamlessly fits into the infrastructure of a surgical navigation system. We have assessed the extent to which stereoscopic visualization improves target localization in computer-aided surgery in a phantom study. In order to quantify the depth perception of a user aiming at a given target, we have designed a phantom simulating typical clinical situations in skull base surgery. Sixteen steel spheres were fixed at the base of a bony skull, and several typical craniotomies were applied. After having taken CT scans, the skull was filled with opaque jelly in order to simulate brain tissue. The positions of the spheres were registered using VISIT, a system for computer-aided surgical navigation. Then attempts were made to locate the steel spheres with a bayonet probe through the craniotomies using VISIT and the Varioscope AR as a stereoscopic display device. Localization of targets 4 mm in diameter using stereoscopic vision and additional visual cues indicating target proximity had a success rate (defined as a first-trial hit rate) of 87.5%. Using monoscopic vision and target proximity indication, the success rate was found to be 66.6%. Omission of visual hints on reaching a target yielded a success rate of 79.2% in the stereo case and 56.25% with monoscopic vision. Time requirements for localizing all 16 targets ranged from 7.5 min (stereo, with proximity cues) to 10 min (mono, without proximity cues). Navigation error is primarily governed by the accuracy of registration in the navigation system, whereas the HMD does not appear to influence localization significantly. We conclude that stereo vision is a valuable tool in augmented reality guided interventions. PMID:12608617

  2. Three dimensional audio versus head down TCAS displays

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.; Pittman, Marc T.

    1994-01-01

    The advantage of a head up auditory display was evaluated in an experiment designed to measure and compare the acquisition time for capturing visual targets under two conditions: Standard head down traffic collision avoidance system (TCAS) display, and three-dimensional (3-D) audio TCAS presentation. Ten commercial airline crews were tested under full mission simulation conditions at the NASA Ames Crew-Vehicle Systems Research Facility Advanced Concepts Flight Simulator. Scenario software generated targets corresponding to aircraft which activated a 3-D aural advisory or a TCAS advisory. Results showed a significant difference in target acquisition time between the two conditions, favoring the 3-D audio TCAS condition by 500 ms.

  3. First Use of Heads-up Display for Astronomy Education

    NASA Astrophysics Data System (ADS)

    Mumford, Holly; Hintz, E. G.; Jones, M.; Lawler, J.; Fisler, A.

    2013-01-01

    As part of our work on deaf education in a planetarium environment we are exploring the use of heads-up display systems. This allows us to overlap an ASL interpreter with our educational videos. The overall goal is to allow a student to watch a full-dome planetarium show and have the interpreter tracking to any portion of the video. We will present the first results of using a heads-up display to provide an ASL ‘sound-track’ for a deaf audience. This work is partially funded by an NSF IIS-1124548 grant and funding from the Sorenson Foundation.

  4. A helmet mounted display demonstration unit for a Space Station application

    NASA Technical Reports Server (NTRS)

    Gernux, Carolyn G.; Blaser, Robert W.; Marmolejo, Jose

    1989-01-01

    Under NASA guidance an advanced development helmet mounted display (HMD) has been designed and fabricated. Delivery has been made of an extravehicular mobility unit (EMU) HMD demonstration unit as an alternative to the current low-resolution, chest-mounted display, and cuff-mounted checklists. Important design goals achieved with this HMD include the use of transmissive liquid display image sources with fairly high resolution (text, graphics, and video compatible), binocular viewing with total image overlap, virtual image projection, low profile packaging, low power design, and demonstration of voice control of the HMD data. Test results showed that the HMD program successfully demonstrated the feasibility of the concept and operated as designed, meeting the necessary program requirements.

  5. Attentional tunneling and the head-up display

    NASA Technical Reports Server (NTRS)

    Wickens, Christopher D.; Martin-Emerson, Robin; Larish, Inge

    1993-01-01

    Twenty instrument-rated flight students flew simulated landing approaches to a realistic graphics generated airport, using either a head-up display (HUD) of instrument landing systems (ILS) instruments or the same display positioned 8.5 deg. head down. Responses to discrete events appearing either on the ground environment or on the instrument display assessed the pilot's ability to switch attention between these domains. Unexpected events also occurred once (per subject) in each domain. The results revealed that flight path control and attention switching to the instrumnet display was better supported by the HUD, while this advantage disappeared for attention switching to the environment, and for detection of unexpected events. The results are discussed in terms of the attention strategies employed in sampling multiple information sources.

  6. Integrated head package for top mounted nuclear instrumentation

    DOEpatents

    Malandra, Louis J.; Hornak, Leonard P.; Meuschke, Robert E.

    1993-01-01

    A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted. The shroud forms a structural element of sufficient strength to support the vessel head, the control rod guide mechanism and the instrumentation tube structure, and includes radiation shielding material for limiting passage of radiation from retracted instrumentation tubes. The shroud is thicker at the bottom adjacent the vessel head, where the more irradiated lower ends of retracted sensors reside. The vessel head, shroud and contents thus can be removed from the reactor as a unit and rested safely and securely on a support.

  7. Target detection performance in helmet-mounted and conventional dome displays.

    PubMed

    Hettinger, L J; Nelson, W T; Haas, M W

    1996-01-01

    An experiment was conducted to assess visual target detection performance using a helmet-mounted display (HMD) and a conventional flight simulation dome display. Measures of workload and mood were also obtained. Participants in both viewing conditions scanned an area 120 degrees vertical by 240 degrees horizontal while attempting to locate targets that appeared to be approaching them from one of a possible 18 locations. Results indicated significantly superior performance in the conventional dome display. Workload and mood measures also showed a significant advantage for the dome display. Results are discussed in terms of their implications for the design and use of HMD systems as components of airborne virtual environment interfaces.

  8. Time Counts! Some Comments on System Latency in Head-Referenced Displays

    NASA Technical Reports Server (NTRS)

    Ellis, Stephen R.; Adelstein, Bernard D.

    2013-01-01

    System response latency is a prominent characteristic of human-computer interaction. Laggy systems are; however, not simply annoying but substantially reduce user productivity. The impact of latency on head referenced display systems, particularly head-mounted systems, is especially disturbing since not only can it interfere with dynamic registration in augmented reality displays but it also can in some cases indirectly contribute to motion sickness. We will summarize several experiments using standard psychophysical discrimination techniques that suggest what system latencies will be required to achieve perceptual stability for spatially referenced computer-generated imagery. In conclusion I will speculate about other system performance characteristics that I would hope to have for a dream augmented reality system.

  9. Integration, development, and qualification of the helmet-mounted sight and display on the Rooivalk Attack Helicopter

    NASA Astrophysics Data System (ADS)

    Mace, Timothy K.; Van Zyl, Petrus H.; Cross, Trevor

    2001-08-01

    The Rooivalk Attack Helicopter is designed and manufactured by Denel Aviation of South Africa, and in service with the South African Air Force. The Helmet Mounted Sight and Display (HMSD) hardware is manufactured by Sextant Avionique of France. The HMSD symbology is developed by Denel Aviation and is specific to the weapons and roles of the aircraft. The HMSD has visor projected NVG and PNVS images, and Flight and Weapon Symbology incorporating head slaved weapon aiming, helmet-to-helmet cueing, and helmet to main sight cueing. The NVG/PNVS image selection and main image controls are incorporated in the flight controls. The paper gives an overview of the aircraft visionic design and describes the integration process. The development of the displayed flight and weapon symbols is discussed. Aeronautical Design Standard 33E was chosen as a basis for the qualification process, and the development of the qualification criteria and the flight testing program are discussed.

  10. The application of holographic optical waveguide technology to the Q-Sight family of helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Cameron, Alex

    2009-05-01

    Traditionally head up displays and helmet mounted displays use a conventional arrangement of complex lenses to generate a display for the pilot from an image source such as a Cathode Ray Tube (CRT) or Liquid Crystal Display (LCD). These systems tend to be complex, comprising many components and they also add mass and adversely modify the centre of the gravity of the helmet. This has resulted in the development of the Holographic Optical Waveguide, a revolutionary new optical technology which dramatically reduces size and mass whilst liberating the designer from many of the constraints inherent in conventional optical solutions. This technology is basically a way of moving light without the need for a complex arrangement of conventional lenses. This is made possible by embedding within the substrate a specially designed hologram which has carefully tailored set of optical properties. The image (or light waves) is constrained to follow a path through the substrate. As these waves pass through the substrate the hologram is programmed to allow some energy to escape in a carefully controlled manner reforming the image that was injected into the substrate. At the same time the hologram design modifies the image geometry such that the user views it as a full size conformal image precisely overlaid on his outside world view. Furthermore this image is maintained over a very large exit-pupil giving the user great flexibility in the installation of the display onto a helmet. The image is formed conventionally from a reflective LCD illuminated with a high brightness LED. The Q-SightTM Helmet Mounted Display (HMD) which exploits this concept is part of a modular-family of Helmet Mounted Displays; allowing the addition of capability as required in a flexible, low-cost way. The basic monocular QSightTM architecture offers plug-and-play solutions into any cockpit with either Analog (stroke) or Digital Video Interface (DVI) connections. This offers a significant upgrade opportunity

  11. Pathway Concepts Experiment for Head-Down Synthetic Vision Displays

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Kramer, Lynda J.; Bailey, Randall E.

    2004-01-01

    Eight 757 commercial airline captains flew 22 approaches using the Reno Sparks 16R Visual Arrival under simulated Category I conditions. Approaches were flown using a head-down synthetic vision display to evaluate four tunnel ("minimal", "box", "dynamic pathway", "dynamic crow s feet") and three guidance ("ball", "tadpole", "follow-me aircraft") concepts and compare their efficacy to a baseline condition (i.e., no tunnel, ball guidance). The results showed that the tunnel concepts significantly improved pilot performance and situation awareness and lowered workload compared to the baseline condition. The dynamic crow s feet tunnel and follow-me aircraft guidance concepts were found to be the best candidates for future synthetic vision head-down displays. These results are discussed with implications for synthetic vision display design and future research.

  12. Pathway concepts experiment for head-down synthetic vision displays

    NASA Astrophysics Data System (ADS)

    Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Kramer, Lynda J.; Bailey, Randall E.

    2004-08-01

    Eight 757 commercial airline captains flew 22 approaches using the Reno Sparks 16R Visual Arrival under simulated Category I conditions. Approaches were flown using a head-down synthetic vision display to evaluate four tunnel ("minimal", "box", "dynamic pathway", "dynamic crow's feet") and three guidance ("ball", "tadpole", "follow-me aircraft") concepts and compare their efficacy to a baseline condition (i.e., no tunnel, ball guidance). The results showed that the tunnel concepts significantly improved pilot performance and situation awareness and lowered workload compared to the baseline condition. The dynamic crow's feet tunnel and follow-me aircraft guidance concepts were found to be the best candidates for future synthetic vision head-down displays. These results are discussed with implications for synthetic vision display design and future research.

  13. Contributions of Head-Mounted Cameras to Studying the Visual Environments of Infants and Young Children

    ERIC Educational Resources Information Center

    Smith, Linda B.; Yu, Chen; Yoshida, Hanako; Fausey, Caitlin M.

    2015-01-01

    Head-mounted video cameras (with and without an eye camera to track gaze direction) are being increasingly used to study infants' and young children's visual environments and provide new and often unexpected insights about the visual world from a child's point of view. The challenge in using head cameras is principally conceptual and concerns the…

  14. Head Worn Display System for Equivalent Visual Operations

    NASA Technical Reports Server (NTRS)

    Cupero, Frank; Valimont, Brian; Wise, John; Best. Carl; DeMers, Bob

    2009-01-01

    Head-Worn Displays or so-called, near-to-eye displays have potentially significant advantages in terms of cost, overcoming cockpit space constraints, and for the display of spatially-integrated information. However, many technical issues need to be overcome before these technologies can be successfully introduced into commercial aircraft cockpits. The results of three activities are reported. First, the near-to-eye display design, technological, and human factors issues are described and a literature review is presented. Second, the results of a fixed-base piloted simulation, investigating the impact of near to eye displays on both operational and visual performance is reported. Straight-in approaches were flown in simulated visual and instrument conditions while using either a biocular or a monocular display placed on either the dominant or non-dominant eye. The pilot's flight performance, visual acuity, and ability to detect unsafe conditions on the runway were tested. The data generally supports a monocular design with minimal impact due to eye dominance. Finally, a method for head tracker system latency measurement is developed and used to compare two different devices.

  15. Head-Worn Displays for NextGen

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Shelton, Kevin J.; Arthur, J. J.

    2011-01-01

    The operating concepts emerging under the Next Generation air transportation system (NextGen) require new technology and procedures - not only on the ground-side - but also on the flight deck. Flight deck display and decision support technologies are specifically targeted to overcome aircraft safety barriers that might otherwise constrain the full realization of NextGen. One such technology is the very lightweight, unobtrusive head-worn display (HWD). HWDs with an integrated head-tracking system are being researched as they offer significant potential benefit under emerging NextGen operational concepts. Two areas of benefit for NextGen are defined. First, the HWD may be designed to be equivalent to the Head-Up Display (HUD) using Virtual HUD concepts. As such, these operational credits may be provided to significantly more aircraft for which HUD installation is neither practical nor possible. Second, the HWD provides unique display capabilities, such as an unlimited field-of-regard. These capabilities may be integral to emerging NextGen operational concepts, eliminating safety issues which might otherwise constrain the full realization of NextGen. The paper details recent research results, current HWD technology limitations, and future technology development needed to realize HWDs as a enabling technology for NextGen.

  16. Psychophysical Research in Development of a Fiber-optic Helmet Mounted Display

    NASA Technical Reports Server (NTRS)

    Kruk, R. V.; Longridge, T. M.

    1984-01-01

    The Fiber Optic Helmet Mounted Display (FOHMD) was conceived as an innovative solution to existing flight simulator display deficiencies. An initial (breadboard) version of the system was fabricated to permit experimentation which would help define design requirements for a more refined engineering prototype. A series of visual/human factors studies are being conducted at the USAF Human Resources Laboratory (AFHRL) Operations Training Division, Williams AFB, Arizona to determine the optimum fit of human observer operating characteristics and fiber optic helmet mounted display technology. Pilot performance within a variety of high resolution insert/binocular overlap combinations is being assessed in two classes of environment. The first two of four studies planned incorporate an air-to-air combat environment, whereas the second two studies will use a low level environment with air to ground weapons delivery.

  17. An experimental evaluation of head-up display formats

    NASA Technical Reports Server (NTRS)

    Naish, J. M.; Miller, D. L.

    1980-01-01

    Three types of head-up display format are investigated. Type 1 is an unreferenced (conventional) flight director, type 2 is a ground referenced flight path display, and type 3 is a ground referenced director. Formats are generated by computer and presented by reflecting collimation against a simulated forward view in flight. Pilots, holding commercial licenses, fly approaches in the instrument flight mode and in a combined instrument and visual flight mode. The approaches are in wind shear with varied conditions of visibility, offset, and turbulence. The displays are equivalent in pure tracking but there is a slight advantage for the unreferenced director in poor conditions. Flight path displays are better for tracking in the combined flight mode, possibly because of poor director control laws and the division of attention between superimposed fields. Workloads is better for the type 2 displays. The flight path and referenced director displays are criticized for effects of symbol motion and field limiting. In the subjective judgment of pilots familiar with the director displays, they are rated clearly better than path displays, with a preference for the unreferenced director. There is a fair division of attention between superimposed fields.

  18. LED light sources for head-up displays

    NASA Astrophysics Data System (ADS)

    Wanninger, Mario

    2005-02-01

    The concept of Head-Up Displays is simple: move the important information a driver needs to see up into their line of sight, so they don"t have to take their eyes off the road. A projected image appears to be floating freely over the hood, at a distance of approximately two meters. Mirrors direct light from an image-generating LCD to the windshield where it is superimposed with the driver"s field of view. The LCD is lit with an appropriate light source. Requirements like long lifetime, vibration resistance, thermal stability and high luminance make LED light sources ideal for use in the automotive industry. The paper discusses the principles of the optical system design of an LED light source for Head-Up Displays.

  19. Contributions of head-mounted cameras to studying the visual environments of infants and young children

    PubMed Central

    Smith, Linda; Yu, Chen; Yoshida, Hanako; Fausey, Caitlin M.

    2014-01-01

    Head-mounted video cameras (with and without an eye camera to track gaze direction) are being increasingly used to study infants’ and young children’s visual environments and provide new and often unexpected insights about the visual world from a child’s point of view. The challenge in using head cameras is principally conceptual and concerns the match between what these cameras measure and the research question. Head cameras record the scene in front of faces and thus answer questions about those head-centered scenes. In this “tools of the trade” article, we consider the unique contributions provided by head-centered video, the limitations and open questions that remain for head-camera methods, and the practical issues of placing head-cameras on infants and analyzing the generated video. PMID:26257584

  20. Consideration of technologies for head-down displays

    NASA Astrophysics Data System (ADS)

    Bartlett, Christopher T.

    1998-09-01

    The market for military avionics head down displays for which Active Matrix Liquid Crystal Displays (AMLCD) has been specified is both well established and substantial. Typical major programs such as F-22, V-22 and Joint Strike Fighter (JSF) amount to over 15,000 displays. Nevertheless there is an insecurity about the situation because of the dependency upon Japanese and Korean manufacturers and the vagaries of the commercial market. The U.S. has only 7% of the world's manufacturing capability in AMLCD and is seeking alternative technologies to regain a hold in this lucrative business. The U.S. military manufacturers of AMLCD are capable, but can never achieve the benefits of scale that Commercial Off The Shelf (COTS) equipment can offer. In addition to the commercial and political concerns, there are still performance issues related to AMLCD and there is a view that emissive displays in particular can offer advantages over AMLCD. However, it is beneficial to be able to tailor display sizes and there are doubts about the ability of current flat panel technologies to achieve custom, or indeed large area panels either economically, or reliably. It is in this arena that projection displays may be the optimum solution.

  1. Terrain Portrayal for Head-Down Displays Experiment

    NASA Technical Reports Server (NTRS)

    Hughes, Monica F.; Takallu, M. A.

    2002-01-01

    The General Aviation Element of the Aviation Safety Program's Synthetic Vision Systems (SVS) Project is developing technology to eliminate low visibility induced General Aviation (GA) accidents. SVS displays present computer generated 3-dimensional imagery of the surrounding terrain on the Primary Flight Display (PFD) to greatly enhance pilot's situation awareness (SA), reducing or eliminating Controlled Flight into Terrain, as well as Low-Visibility Loss of Control accidents. SVS-conducted research is facilitating development of display concepts that provide the pilot with an unobstructed view of the outside terrain, regardless of weather conditions and time of day. A critical component of SVS displays is the appropriate presentation of terrain to the pilot. An experimental study has been conducted at NASA Langley Research Center (LaRC) to explore and quantify the relationship between the realism of the terrain presentation and resulting enhancements of pilot SA and pilot performance. Composed of complementary simulation and flight test efforts, Terrain Portrayal for Head-Down Displays (TP-HDD) experiments will help researchers evaluate critical terrain portrayal concepts. The experimental effort is to provide data to enable design trades that optimize SVS applications, as well as develop requirements and recommendations to facilitate the certification process. This paper focuses on the experimental set-up and preliminary qualitative results of the TP-HDD simulation experiment. In this experiment a fixed based flight simulator was equipped with various types of Head Down flight displays, ranging from conventional round dials (typical of most GA aircraft) to glass cockpit style PFD's. The variations of the PFD included an assortment of texturing and Digital Elevation Model (DEM) resolution combinations. A test matrix of 10 terrain display configurations (in addition to the baseline displays) were evaluated by 27 pilots of various backgrounds and experience levels

  2. Head-up and head-down displays integration in automobiles

    NASA Astrophysics Data System (ADS)

    Betancur, J. Alejandro; Osorio-Gómez, Gilberto; Agudelo, J. David

    2014-06-01

    In automotive industry, the dashboard has been ergonomically developed in order to keep the driver focused on the horizon while driving, but the possibility to access external electronic devices constraints the driver to turn away his face, generating dangerous situations in spite of the short periods of time. Therefore, this work explores the integration of Head-Up Displays and Head-Down Displays in automobiles, proposing configurations that give to drivers the facility to driving focused. In this way, some of the main ergonomic comments about those configurations are proposed; and also, some technical comments regarding the implemented arrangements are given.

  3. Advances and trends of head-up and head-down display systems in automobiles

    NASA Astrophysics Data System (ADS)

    Betancur, J. Alejandro; Osorio-Gomez, Gilberto; Agudelo, J. David

    2014-06-01

    Currently, in the automotive industry the interaction between drivers and Augmented Reality (AR) systems is a subject of analysis, especially the identification of advantages and risks that this kind of interaction represents. Consequently, this paper attempts to put in evidence the potential applications of Head-Up (Display (HUD) and Head-Down Display (HDD) systems in automotive vehicles, showing applications and trends under study. In general, automotive advances related to AR devices suggest the partial integration of the HUD and HDD in automobiles; however, the right way to do it is still a moot point.

  4. Helmet-mounted display human factor engineering design issues: past, present, and future

    NASA Astrophysics Data System (ADS)

    Licina, Joseph R.; Rash, Clarence E.; Mora, John C.; Ledford, Melissa H.

    1999-07-01

    An often overlooked area of helmet-mounted display (HMD) design is that of good human factors engineering. Systems which pass bench testing with flying colors can often find less enthusiastic acceptance during fielding when good human factors engineering principles are not adhered to throughout the design process. This paper addresses lessons learned on the fielding of the AH-64 Apache Integrated Helmet and Display Sight System (IHADSS) and the Aviator's Night Vision Imaging System (ANVIS). These lessons are used to develop guidance for future HMDs in such diverse areas as: user adjustments, anthropometry, fit and comfort, manpower and personnel requirements, and equipment compatibility.

  5. Performance Comparison Between a Head-Worn Display System and a Head-Up Display for Low Visibility Commercial Operations

    NASA Technical Reports Server (NTRS)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Barnes, James R.; Williams, Steven P.; Jones, Denise R.; Harrison, Stephanie J.; Bailey, Randall E.

    2014-01-01

    Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in Next Generation Air Transportation System (NextGen). Under the Vehicle Systems Safety Technologies (VSST) project in the Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as an equivalent display to a Head-Up Display (HUD). Title 14 of the US Code of Federal Regulations (CFR) 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent" display combined with Enhanced Vision (EV). If successful, a HWD may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A simulation experiment was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Comparative testing was performed in the Research Flight Deck (RFD) Cockpit Motion Facility (CMF) full mission, motion-based simulator at NASA Langley. Twelve airline crews conducted approach and landing, taxi, and departure operations during low visibility operations (1000' Runway Visual Range (RVR), 300' RVR) at Memphis International Airport (Federal Aviation Administration (FAA) identifier: KMEM). The results showed that there were no statistical differences in the crews performance in terms of touchdown and takeoff. Further, there were no statistical differences between the HUD and HWD in pilots' responses to questionnaires.

  6. Performance comparison between a head-worn display system and a head-up display for low visibility commercial operations

    NASA Astrophysics Data System (ADS)

    Arthur, Jarvis J.; Prinzel, Lawerence J.; Barnes, James R.; Williams, Steven P.; Jones, Denise R.; Harrison, Stephanie J.; Bailey, Randall E.

    2014-06-01

    Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in Next Generation Air Transportation System (NextGen). Under the Vehicle Systems Safety Technologies (VSST) project in the Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as an equivalent display to a Head-Up Display (HUD). Title 14 of the US Code of Federal Regulations (CFR) 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent" display combined with Enhanced Vision (EV). If successful, a HWD may provide the same safety and operational benefits as current BUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A simulation experiment was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Comparative testing was performed in the Research Flight Deck (RFD) Cockpit Motion Facility (CMF) full mission, motion-based simulator at NASA Langley. Twelve airline crews conducted approach and landing, taxi, and departure operations during low visibility operations (1000' Runway Visual Range (RVR), 300' RVR) at Memphis International Airport (Federal Aviation Administration (FAA) identifier: KMEM). The results showed that there were no statistical differences in the crews performance in terms of touchdown and takeoff. Further, there were no statistical differences between the HUD and HWD in pilots' responses to questionnaires.

  7. Head-mounted active noise control system with virtual sensing technique

    NASA Astrophysics Data System (ADS)

    Miyazaki, Nobuhiro; Kajikawa, Yoshinobu

    2015-03-01

    In this paper, we apply a virtual sensing technique to a head-mounted active noise control (ANC) system we have already proposed. The proposed ANC system can reduce narrowband noise while improving the noise reduction ability at the desired locations. A head-mounted ANC system based on an adaptive feedback structure can reduce noise with periodicity or narrowband components. However, since quiet zones are formed only at the locations of error microphones, an adequate noise reduction cannot be achieved at the locations where error microphones cannot be placed such as near the eardrums. A solution to this problem is to apply a virtual sensing technique. A virtual sensing ANC system can achieve higher noise reduction at the desired locations by measuring the system models from physical sensors to virtual sensors, which will be used in the online operation of the virtual sensing ANC algorithm. Hence, we attempt to achieve the maximum noise reduction near the eardrums by applying the virtual sensing technique to the head-mounted ANC system. However, it is impossible to place the microphone near the eardrums. Therefore, the system models from physical sensors to virtual sensors are estimated using the Head And Torso Simulator (HATS) instead of human ears. Some simulation, experimental, and subjective assessment results demonstrate that the head-mounted ANC system with virtual sensing is superior to that without virtual sensing in terms of the noise reduction ability at the desired locations.

  8. Superimposition, symbology, visual attention, and the head-up display

    NASA Technical Reports Server (NTRS)

    Martin-Emerson, R.; Wickens, C. D.

    1997-01-01

    In two experiments we examined a number of related factors postulated to influence head-up display (HUD) performance. We addressed the benefit of reduced scanning and the cost of increasing the number of elements in the visual field by comparing a superimposed HUD with an identical display in a head-down position in varying visibility conditions. We explored the extent to which the characteristics of HUD symbology support a division of attention by contrasting conformal symbology (which links elements of the display image to elements of the far domain) with traditional instrument landing system (ILS) symbology. Together the two experiments provide strong evidence that minimizing scanning between flight instruments and the far domain contributes substantially to the observed HUD performance advantage. Experiment 1 provides little evidence for a performance cost attributable to visual clutter. In Experiment 2 the pattern of differences in lateral tracking error between conformal and traditional ILS symbology supports the hypothesis that, to the extent that the symbology forms an object with the far domain, attention may be divided between the superimposed image and its counterpart in the far domain.

  9. Helmet mounted display supporting helicopter missions during en route flight and landing

    NASA Astrophysics Data System (ADS)

    Lueken, Thomas; Doehler, Hans-Ullrich; Schmerwitz, Sven

    2016-05-01

    Degraded visual environment is still a major problem for helicopter pilots especially during approach and landing. Particularly with regard to the landing phase, pilot's eyes must be directed outward in order to find visual cues as indicators for drift estimation. If lateral speed exceeds the limits it can damage the airframe or in extreme cases lead to a rollover. Since poor visibility can contribute to a loss of situation awareness and spatial disorientation, it is crucial to intuitively provide the pilot with the essential visual information he needs for a safe landing. With continuous technology advancement helmet-mounted displays (HMD) will soon become a spreading technology, because look through capability is an enabler to offer monitoring the outside view while presenting flight phase depending symbologies on the helmet display. Besides presenting primary flight information, additional information for obstacle accentuation or terrain visualization can be displayed on the visor. Virtual conformal elements like 3D pathway depiction or a 3D landing zone representation can help the pilot to maintain control until touchdown even during poor visual conditions. This paper describes first investigations in terms of both en route and landing symbology presented on a helmet mounted display system in the scope of helicopter flight trials with DLR's flying helicopter simulator ACT/FHS.

  10. Head-Mounted Eye Tracking: A New Method to Describe Infant Looking

    ERIC Educational Resources Information Center

    Franchak, John M.; Kretch, Kari S.; Soska, Kasey C.; Adolph, Karen E.

    2011-01-01

    Despite hundreds of studies describing infants' visual exploration of experimental stimuli, researchers know little about where infants look during everyday interactions. The current study describes the first method for studying visual behavior during natural interactions in mobile infants. Six 14-month-old infants wore a head-mounted eye-tracker…

  11. Toward Head-Worn Displays for Equivalent Visual Operations

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence (Lance) J., III; Arthur, Jarvis J. (Trey); Bailey, Randall E.; Jones, Denise R.; Williams, Steven P.; Harrison, Stephanie J.

    2015-01-01

    The Next Generation Air Transportation System represents an envisioned transformation to the U.S. air transportation system that includes an "equivalent visual operations" (EVO) concept, intended to achieve the safety and operational tempos of Visual Flight Rules (VFR) operations independent of visibility conditions. Today, Federal Aviation Administration regulations provide for the use of an Enhanced Flight Visual System (EFVS) as "operational credit" to conduct approach operations below traditional minima otherwise prohibited. An essential element of an EFVS is the Head-Up Display (HUD). NASA has conducted a substantial amount of research investigating the use of HUDs for operational landing "credit", and current efforts are underway to enable manually flown operations as low as 1000 feet Runway Visual Range (RVR). Title 14 CFR 91.175 describes the use of EFVS and the operational credit that may be obtained with airplane equipage of a HUD combined with Enhanced Vision (EV) while also offering the potential use of an “equivalent” display in lieu of the HUD. A Head-Worn Display (HWD) is postulated to provide the same, or better, safety and operational benefits as current HUD-equipped aircraft but for potentially more aircraft and for lower cost. A high-fidelity simulation was conducted that examined the efficacy of HWDs as "equivalent" displays. Twelve airline flight crews conducted 1000 feet RVR approach and 300 feet RVR departure operations using either a HUD or HWD, both with simulated Forward Looking Infra-Red cameras. The paper shall describe (a) quantitative and qualitative results, (b) a comparative evaluation of these findings with prior NASA HUD studies, and (c) describe current research efforts for EFVS to provide for a comprehensive EVO capability.

  12. Helmet-mounted display and associated research activities recently conducted by the NASA Johnson Space Center

    NASA Astrophysics Data System (ADS)

    Marmolejo, Jose A.

    1994-06-01

    To enhance manned extravehicular activity (EVA) utilizing an extravehicular mobility unit (EMU)(i.e., a space suit and portable life support backpack), NASA has conducted research into implementing helmet mounted display (HMD) and related technology within its next generation of space suits. The NASA/Johnson Space Center has completed four feasibility development programs for the design and development of an EMU HMD, each resulting in the delivery of a binocular or biocular HMD breadboard unit utilizing conventional optical elements (i.e., glass lenses and beamsplitters) and/or holographic optics. Additional research into combining the use of voice recognition for astronaut 'hands- free' access to information via the HMD has also been conducted. Research conducted since 1983 will be summarized along with current shuttle EMU display enhancements. In addition, recommendations for the design of the next generation of displays for use within the EMU will be presented.

  13. A novel active heads-up display for driver assistance.

    PubMed

    Doshi, Anup; Cheng, Shinko Yuanhsien; Trivedi, Mohan Manubhai

    2009-02-01

    In this paper, we introduce a novel laser-based wide-area heads-up windshield display which is capable of actively interfacing with a human as part of a driver assistance system. The dynamic active display (DAD) is a unique prototype interface that presents safety-critical visual icons to the driver in a manner that minimizes the deviation of his or her gaze direction without adding to unnecessary visual clutter. As part of an automotive safety system, the DAD presents alerts in the field of view of the driver only if necessary, which is based upon the state and pose of the driver, vehicle, and environment. This paper examines the effectiveness of DAD through a comprehensive comparative experimental evaluation of a speed compliance driver assistance system, which is implemented on a vehicular test bed. Three different types of display protocols for assisting a driver to comply with speed limits are tested on actual roadways, and these are compared with a conventional dashboard display. Given the inclination, drivers who are given an overspeed warning alert reduced the time required to slow down to the speed limit by 38% (p < 0.01) as compared with the drivers not given the alert. Additionally, certain alerts decreased distraction levels by reducing the time spent looking away from the road by 63% (p < 0.01). Ultimately, these alerts demonstrate the utility and promise of the DAD system.

  14. Pathway design effects on synthetic vision head-up displays

    NASA Astrophysics Data System (ADS)

    Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

    2004-08-01

    NASA's Synthetic Vision Systems (SVS) project is developing technologies with practical applications that will eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced pathway guidance for transport aircraft. This experiment evaluated the influence of different tunnel and guidance concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two tunnel formats (dynamic, minimal) were evaluated against a baseline condition (no tunnel) during simulated IMC approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence on the tunnel formats. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

  15. Pathway Design Effects on Synthetic Vision Head-Up Displays

    NASA Technical Reports Server (NTRS)

    Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

    2004-01-01

    NASA s Synthetic Vision Systems (SVS) project is developing technologies with practical applications that will eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced pathway guidance for transport aircraft. This experiment evaluated the influence of different tunnel and guidance concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two tunnel formats (dynamic, minimal) were evaluated against a baseline condition (no tunnel) during simulated IMC approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence on the tunnel formats. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

  16. Study for verification testing of the helmet-mounted display in the Japanese Experimental Module.

    PubMed

    Nakajima, I; Yamamoto, I; Kato, H; Inokuchi, S; Nemoto, M

    2000-02-01

    Our purpose is to propose a research and development project in the field of telemedicine. The proposed Multimedia Telemedicine Experiment for Extra-Vehicular Activity will entail experiments designed to support astronaut health management during Extra-Vehicular Activity (EVA). Experiments will have relevant applications to the Japanese Experimental Module (JEM) operated by National Space Development Agency of Japan (NASDA) for the International Space Station (ISS). In essence, this is a proposal for verification testing of the Helmet-Mounted Display (HMD), which enables astronauts to verify their own blood pressures and electrocardiograms, and to view a display of instructions from the ground station and listings of work procedures. Specifically, HMD is a device designed to project images and data inside the astronaut's helmet. We consider this R&D proposal to be one of the most suitable projects under consideration in response to NASDA's open invitation calling for medical experiments to be conducted on JEM.

  17. Microstructured head-up display screen for automotive applications

    NASA Astrophysics Data System (ADS)

    Hedili, M. Kivanc; Freeman, Mark O.; Urey, Hakan

    2012-06-01

    A novel see-through screen is developed for automobiles which reduces the size of the head-up display (HUD) unit considerably. The screen is illuminated by a laser scanning pico-projector and a real image is formed on the screen. The screen has thousands of hexagonally packed microlenses that are partially reflective and embedded in an index matched medium which provides very good see-through capability. Light reflected from the microlenses expand and form a hexagon shaped viewing window. This system is called a direct projection HUD system as the pico projector projects directly onto the screen and forms a real image on it. The system is very compact and does not require any space under the dashboard, which saves on space for the car manufacturers, or allows it to be used immediately as an aftermarket HUD installed in any car.

  18. Magnitude of visual accommodation to a head-up display

    NASA Technical Reports Server (NTRS)

    Leitner, E. F.; Haines, R. F.

    1981-01-01

    The virtual image symbology of head-up displays (HUDs) is presented at optical infinity to the pilot. This design feature is intended to help pilots maintain visual focus distance at optical infinity. However, the accommodation response could be nearer than optical infinity, due to an individual's dark focus response. Accommodation responses were measured of two age groups of airline pilots to: (1) static symbology on a HUD; (2) a landing site background at optical infinity; (3) the combination of the HUD symbology and the landing site background; and (4) complete darkness. Results indicate that magnitude of accommodation to HUD symbology, with and without the background, is not significantly different from an infinity focus response for either age group. The dark focus response is significantly closer than optical infinity for the younger pilots, but not the older pilots, a finding consistent with previous research.

  19. Impact of helmet-mounted display visor spectral characteristics on visual performance

    NASA Astrophysics Data System (ADS)

    Marasco, Peter L.

    2002-08-01

    Visors are an important component in modern helmet-mounted displays (HMDs). In addition to their more conventional use as eye protection, they can be used as the final element in the optical system that relays visual information to the observer. To enhance their usefulness as the final optical element (as a beam splitter or image combiner), visors are sometimes coated to increase their reflectivity and improve the efficiency of the optics. However, pilots often object to the addition of reflective patches, indicating, among other reasons, that they decrease observed target contrast and, therefore, decrease target detection range. This paper will examine the impact of the additional reflective coating on visual performance through a helmet-mounted display visor. It will propose design parameters based on the spectral nature of the coating that might make it more useful to both the HMD designer and to the HMD wearer. Finally, this paper will examine visual phenomena that may affect visual performance through a coated visor.

  20. Terrain Portrayal for Head-Down Displays Flight Test

    NASA Technical Reports Server (NTRS)

    Hughes, Monica F.; Glaab, Louis J.

    2003-01-01

    The Synthetic Vision Systems General Aviation (SVS-GA) element of NASA's Aviation Safety Program is developing technology to eliminate low visibility induced General Aviation (GA) accidents through the application of synthetic vision techniques. SVS displays present computer generated 3-dimensional imagery of the surrounding terrain to greatly enhance pilot's situation awareness (SA), reducing or eliminating Controlled Flight into Terrain (CFIT), as well as Low-Visibility Loss of Control (LVLOC) accidents. In addition to substantial safety benefits, SVS displays have many potential operational benefits that can lead to flight in instrument meteorological conditions (IMC) resembling those conducted in visual meteorological conditions (VMC). Potential benefits could include lower landing minimums, more approach options, reduced training time, etc. SVS conducted research will develop display concepts providing the pilot with an unobstructed view of the outside terrain, regardless of weather conditions and time of day. A critical component of SVS displays is the appropriate presentation of terrain to the pilot. The relationship between the realism of the terrain presentation and resulting enhancements of pilot SA and pilot performance has been largely undefined. Comprised of coordinated simulation and flight test efforts, the terrain portrayal for head-down displays (TP-HDD) test series examined the effects of two primary elements of terrain portrayal: variations of digital elevation model (DEM) resolution and terrain texturing. Variations in DEM resolution ranged from sparsely spaced (30 arc-sec/2,953ft) to very closely spaced data (1 arc-sec/98 ft). Variations in texture involved three primary methods: constant color, elevation-based generic, and photo-realistic, along with a secondary depth cue enhancer in the form of a fishnet grid overlay. The TP-HDD test series was designed to provide comprehensive data to enable design trades to optimize all SVS applications, as

  1. Visual Field Testing with Head-Mounted Perimeter ‘imo’

    PubMed Central

    Matsumoto, Chota; Yamao, Sayaka; Nomoto, Hiroki; Takada, Sonoko; Okuyama, Sachiko; Kimura, Shinji; Yamanaka, Kenzo; Aihara, Makoto; Shimomura, Yoshikazu

    2016-01-01

    Purpose We developed a new portable head-mounted perimeter, “imo”, which performs visual field (VF) testing under flexible conditions without a dark room. Besides the monocular eye test, imo can present a test target randomly to either eye without occlusion (a binocular random single eye test). The performance of imo was evaluated. Methods Using full HD transmissive LCD and high intensity LED backlights, imo can display a test target under the same test conditions as the Humphrey Field Analyzer (HFA). The monocular and binocular random single eye tests by imo and the HFA test were performed on 40 eyes of 20 subjects with glaucoma. VF sensitivity results by the monocular and binocular random single eye tests were compared, and these test results were further compared to those by the HFA. The subjects were asked whether they noticed which eye was being tested during the test. Results The mean sensitivity (MS) obtained with the HFA highly correlated with the MS by the imo monocular test (R: r = 0.96, L: r = 0.94, P < 0.001) and the binocular random single eye test (R: r = 0.97, L: r = 0.98, P < 0.001). The MS values by the monocular and binocular random single eye tests also highly correlated (R: r = 0.96, L: r = 0.95, P < 0.001). No subject could detect which eye was being tested during the examination. Conclusions The perimeter imo can obtain VF sensitivity highly compatible to that by the standard automated perimeter. The binocular random single eye test provides a non-occlusion test condition without the examinee being aware of the tested eye. PMID:27564382

  2. Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.

    PubMed

    Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L

    2015-06-01

    Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.

  3. Head-up transition behavior of pilots with and without head-up display in simulated low-visibility approaches

    NASA Technical Reports Server (NTRS)

    Haines, R. F.; Fischer, E.; Price, T. A.

    1980-01-01

    To quantify head-up transition behavior with and without a flightpath type head-up display, eight rated B-727 pilots each flew 31 manual and coupled approaches in a simulator with B-727 dynamics and collimated model board external scene. Data were also obtained on the roll played by the head-up display in the coupled-to-manual transition. Various wind shears, low visibilities, and ceilings were tested along with unexpected misalignment between the runway and head-up display symbology. The symbolic format used was a conformal scene. Every pilot except one stayed head-up, flying with the display after descending below the ceiling. Without the display and as altitude decreased, the number of lookups from the instrument panel decreased and the duration of each one increased. No large differences in mean number or duration of transitions up or down were found during the head-up display runs comparing the no-misalignment with the lateral instrument landing system offset misalignment runs. The head-up display led to fewer transitions after the pilot made a decision to land or execute a missed approach. Without the display, pilots generally waited until they had descended below the ceiling to look outside the first time, but with it several pilots looked down at their panel at relatively high altitudes (if they looked down at all). Manual takeover of control was rapid and smooth both with and without the display which permitted smoother engine power changes.

  4. Human interaction with wearable computer systems: a look at glasses-mounted displays

    NASA Astrophysics Data System (ADS)

    Revels, Allen R.; Quill, Laurie L.; Kancler, David E.; Masquelier, Barbara L.

    1998-09-01

    With the advancement of technology and the information explosion, integration of the two into performance aiding systems can have a significant impact on operational and maintenance environments. The Department of Defense and commercial industry have made great strides in digitizing and automating technical manuals and data to be presented on performance aiding systems. These performance aides are computerized interactive systems that provide procedures on how to operate and maintain fielded systems. The idea is to provide the end-user a system which is compatible with their work environment. The purpose of this paper is to show, historically, the progression of wearable computer aiding systems for maintenance environments, and then highlight the work accomplished in the design and development of glasses- mounted displays (GMD). The paper reviews work performed over the last seven years, then highlights, through review of a usability study, the advances made with GMDs. The use of portable computing systems, such as laptop and notebook, computers, does not necessarily increase the accessibility of the displayed information while accomplishing a given task in a hands-busy, mobile work environment. The use of a GMD increases accessibility of the information by placing it in eye sight of the user without obstructing the surrounding environment. Although the potential utility for this type of display is great, hardware and human integration must be refined. Results from the usability study show the usefulness and usability of the GMD in a mobile, hands-free environment.

  5. Operational helmet-mounted display model: prediction of visible grayshades and see-through spectral data

    NASA Astrophysics Data System (ADS)

    Harding, Thomas H.; Klymenko, Victor; Martin, John S.; Rash, Clarence E.

    2002-08-01

    Combat developers and aviation program managers require knowledge of helmet-mounted display (HMD) performance under operational conditions in order to determine HMD luminance and contrast requirements. In order to ease this problem, we developed a computer model that predicts available gray-shades based on hardware, ambient light condition, and HMD properties. Included in the model are windscreens, visors, laser protection devices, and properties of developed and fielded HMDs. A graphical user interface and user variables specification allow the developer/manager to model HMDs in specific aircraft. Included with the model is a color model that predicts see-through color imagery. The model produces a visualization of see-through imagery superimposed with HMD symbology based upon model predictions. This allows the user to view simulated imagery as though he were wearing the HMD.

  6. A miniature shoe-mounted orientation determination system for accurate indoor heading and trajectory tracking.

    PubMed

    Zhang, Shengzhi; Yu, Shuai; Liu, Chaojun; Liu, Sheng

    2016-06-01

    Tracking the position of pedestrian is urgently demanded when the most commonly used GPS (Global Position System) is unavailable. Benefited from the small size, low-power consumption, and relatively high reliability, micro-electro-mechanical system sensors are well suited for GPS-denied indoor pedestrian heading estimation. In this paper, a real-time miniature orientation determination system (MODS) was developed for indoor heading and trajectory tracking based on a novel dual-linear Kalman filter. The proposed filter precludes the impact of geomagnetic distortions on pitch and roll that the heading is subjected to. A robust calibration approach was designed to improve the accuracy of sensors measurements based on a unified sensor model. Online tests were performed on the MODS with an improved turntable. The results demonstrate that the average RMSE (root-mean-square error) of heading estimation is less than 1°. Indoor heading experiments were carried out with the MODS mounted on the shoe of pedestrian. Besides, we integrated the existing MODS into an indoor pedestrian dead reckoning application as an example of its utility in realistic actions. A human attitude-based walking model was developed to calculate the walking distance. Test results indicate that mean percentage error of indoor trajectory tracking achieves 2% of the total walking distance. This paper provides a feasible alternative for accurate indoor heading and trajectory tracking. PMID:27370490

  7. A miniature shoe-mounted orientation determination system for accurate indoor heading and trajectory tracking

    NASA Astrophysics Data System (ADS)

    Zhang, Shengzhi; Yu, Shuai; Liu, Chaojun; Liu, Sheng

    2016-06-01

    Tracking the position of pedestrian is urgently demanded when the most commonly used GPS (Global Position System) is unavailable. Benefited from the small size, low-power consumption, and relatively high reliability, micro-electro-mechanical system sensors are well suited for GPS-denied indoor pedestrian heading estimation. In this paper, a real-time miniature orientation determination system (MODS) was developed for indoor heading and trajectory tracking based on a novel dual-linear Kalman filter. The proposed filter precludes the impact of geomagnetic distortions on pitch and roll that the heading is subjected to. A robust calibration approach was designed to improve the accuracy of sensors measurements based on a unified sensor model. Online tests were performed on the MODS with an improved turntable. The results demonstrate that the average RMSE (root-mean-square error) of heading estimation is less than 1°. Indoor heading experiments were carried out with the MODS mounted on the shoe of pedestrian. Besides, we integrated the existing MODS into an indoor pedestrian dead reckoning application as an example of its utility in realistic actions. A human attitude-based walking model was developed to calculate the walking distance. Test results indicate that mean percentage error of indoor trajectory tracking achieves 2% of the total walking distance. This paper provides a feasible alternative for accurate indoor heading and trajectory tracking.

  8. Evaluation of helmet-mounted display targeting symbology based on eye tracking technology

    NASA Astrophysics Data System (ADS)

    Wang, Lijing; Wen, Fuzhen; Ma, Caixin; Zhao, Shengchu; Liu, Xiaodong

    2014-06-01

    The purpose of this paper is to find the Target Locator Lines (TLLs) which perform best by contrasting and comparing experiment based on three kinds of TTLs of fighter HMD. 10 university students, male, with an average age of 21-23, corrected visual acuity 1.5, participated in the experiment. In the experiment, head movement data was obtained by TrackIR. The geometric relationship between the coordinates of the real world and coordinates of the visual display was obtained by calculating the distance from viewpoint to midpoint of both eyes and the head movement data. Virtual helmet system simulation experiment environment was created by drawing TLLs of fighter HMD in the flight simulator visual scene. In the experiment, eye tracker was used to record the time and saccade trajectory. The results were evaluated by the duration of the time and saccade trajectory. The results showed that the symbol"locator line with digital vector length indication" cost most time and had the longest length of the saccade trajectory. It is the most ineffective and most unacceptable way. "Locator line with extending head vector length symbol" cost less time and had less length of the saccade trajectory. It is effective and acceptable;"Locator line with reflected vector length symbol" cost the least time and had the least length of the saccade trajectory. It is the most effective and most acceptable way. "Locator line with reflected vector length symbol" performs best. The results will provide reference value for the research of TTLs in future.

  9. See-through head-worn display of patient monitoring data to enhance anesthesiologists' response to abnormal clinical events

    NASA Astrophysics Data System (ADS)

    Ormerod, David F.; Ross, Brian K.; Naluai-Cecchini, A.

    2003-05-01

    One obstacle to safety in the operating room is anesthesiologist distraction -- having to shift attention back and forth from the patient to vital sign monitor while performing either routine or emergency procedures. The purpose of this study was to measure the decrease in anesthesiologist distraction made possible by using a head-mounted, see-through personal display (HMD) using retinal scanning technology. With the head-up display, they were able to focus their attention exclusively on the patient and the task at hand. The Nomad reduced the number of times the anesthesiologist had to shift their attention by a more than a third (17 times versus 58 times). This allowed them to spend more time focused on the patient.

  10. Holographic helmet-mounted display application for the extravehicular mobility unit

    NASA Astrophysics Data System (ADS)

    Weinstock, Mark J.; Pishtey, Wallace; LaRussa, Joseph A.; Tritsch, Constance L.

    1990-10-01

    This helmet mounted display (HMD) was designed for the extravehicular mobility unit (EMIJ) to be used on the Space Station Freedom. The HMD will be able to display text, graphics, and video to the astronaut. The image will be above his/her normal field of view (FOV) at a comfortable distance. It is believed that this device would be extraordinarily useful in performing scheduled and emergency extravehicular activities (EVAs) . This HMD may be voiceactivated for true "hands-free" operation, without invading the prime work envelope. The Technology Innovation Group (TIG)/Lockheed Engineering and Sciences Company (LESC) holographic HMD was developed for the Crew and Thermal Systems Division and NASA-Johnson Space Center. This HMD is unique because it uses holographic optical elements (HOEs) on the pressure helmet and protective visor surfaces to relay an image from a CRT directly to the eyebox. This HMD provides the user with a biocular virtual image in a 25 degree diagonal FOV, maximum combiner transparency, minimal volume dimension, and an unencumbered working field of view.

  11. Common software and interface for different helmet-mounted display (HMD) aircraft symbology sets

    NASA Astrophysics Data System (ADS)

    Mulholland, Fred F.

    2000-06-01

    Different aircraft in different services and countries have their own set of symbology they want displayed on their HMD. Even as flight symbolgy is standardized, there will still be some differences for types of aircraft, different weapons, different sensors, and different countries. As an HMD supplier, we want to provide a system that can be used across all these applications with no changes in the system, including no changes in the software. This HMD system must also provide the flexibility to accommodate new symbology as it is developed over the years, again, with no change in the HMD software. VSI has developed their HMD software to accommodate F-15, F- 16, F-18, and F-22 symbology sets for the Joint Helmet Mounted Cueing System. It also has the flexibility to accommodate the aircraft types and services of the Joint Strike Fighter: Conventional Takeoff and Landing variant for the USAF, Carrier-based Variant for the USN, and the Short Takeoff and Vertical Landing variant for the USMC and U.K. Royal Navy and Air Force. The key to this flexibility is the interface definition. The interface parameters are established at power-on with the download of an interface definition data set. This data set is used to interpret symbology commands from the aircraft OFP during operation and provide graphic commands to the HMD software. This presentation will define the graphics commands, provide an example of how the interface definition data set is defined, and then show how symbology commands produce a display.

  12. Toward Head-Up and Head-Worn Displays for Equivalent Visual Operations

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III; Arthur, Jarvis J.; Bailey, Randall E.; Shelton, Kevin J.; Kramer, Lynda J.; Jones, Denise R.; Williams, Steven P.; Harrison, Stephanie J.; Ellis, Kyle K.

    2015-01-01

    A key capability envisioned for the future air transportation system is the concept of equivalent visual operations (EVO). EVO is the capability to achieve the safety of current-day Visual Flight Rules (VFR) operations and maintain the operational tempos of VFR irrespective of the weather and visibility conditions. Enhanced Flight Vision Systems (EFVS) offer a path to achieve EVO. NASA has successfully tested EFVS for commercial flight operations that has helped establish the technical merits of EFVS, without reliance on natural vision, to runways without category II/III ground-based navigation and lighting requirements. The research has tested EFVS for operations with both Head-Up Displays (HUDs) and "HUD equivalent" Head-Worn Displays (HWDs). The paper describes the EVO concept and representative NASA EFVS research that demonstrate the potential of these technologies to safely conduct operations in visibilities as low as 1000 feet Runway Visual Range (RVR). Future directions are described including efforts to enable low-visibility approach, landing, and roll-outs using EFVS under conditions as low as 300 feet RVR.

  13. Head-mounted LED for optogenetic experiments of freely-behaving animal

    NASA Astrophysics Data System (ADS)

    Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

    2016-03-01

    Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

  14. Heads up display for the Flight Simulator for Advanced Aircraft (FSAA)

    NASA Technical Reports Server (NTRS)

    Brocker, D. H.; Ganzler, B. C.

    1975-01-01

    A heads-up flight director display designed for a V/STOL lift-fan transport simulation study is described. The pilot's visual flight scene had the heads-up display optically superimposed over the usual out-the-window, video flight scene. The flight director display required the development and integration of a flexible, programmable display generator, graphics assembler, display driver, computer interface system, and special collimating optics for the pilot's flight scene. The optical overlay was realistic because both scenes appeared at optical infinity, and the flexibility of this display device establishes its value as a research tool for use in future flight simulation programs.

  15. Measurement and reduction of system latency in see-through helmet mounted display (HMD) systems

    NASA Astrophysics Data System (ADS)

    Vincenzi, Dennis A.; Deaton, John E.; Blickenderfer, Elizabeth L.; Pray, Rick; Williams, Barry; Buker, Timothy J.

    2010-04-01

    Future military aviation platforms such as the proposed Joint Strike Fighter F-35 will integrate helmet mounted displays (HMDs) with the avionics and weapon systems to the degree that the HMDs will become the aircraft's primary display system. In turn, training of pilot flight skills using HMDs will be essential in future training systems. In order to train these skills using simulation based training, improvements must be made in the integration of HMDs with out-thewindow (OTW) simulations. Currently, problems such as latency contribute to the onset of simulator sickness and provide distractions during training with HMD simulator systems that degrade the training experience. Previous research has used Kalman predictive filters as a means of mitigating the system latency present in these systems. While this approach has yielded some success, more work is needed to develop innovative and improved strategies that reduce system latency as well as to include data collected from the user perspective as a measured variable during test and evaluation of latency reduction strategies. The purpose of this paper is twofold. First, the paper describes a new method to measure and assess system latency from the user perspective. Second, the paper describes use of the testbed to examine the efficacy of an innovative strategy that combines a customized Kalman filter with a neural network approach to mitigate system latency. Results indicate that the combined approach reduced system latency significantly when compared to baseline data and the traditional Kalman filter. Reduced latency errors should mitigate the onset of simulator sickness and ease simulator sickness symptomology. Implications for training systems will be discussed.

  16. Concepts for conformal and body-axis attitude information for spatial awareness presented in a helmet-mounted display

    NASA Technical Reports Server (NTRS)

    Jones, Denise R.; Abbott, Terence S.; Burley, James R., II

    1993-01-01

    A piloted simulation study has been conducted to evaluate two methods of presenting attitude information in a helmet-mounted display (HMD) for spatial awareness in a fighter airplane. One method, the body-axis concept, displayed the information relative to the body axis of the airplane. The quantitative results of this study favored the body-axis concept. Although no statistically significant differences were noted for either the pilots' understanding of roll attitude or target position, the pilots made pitch judgment errors three times more often with the conformal display. The subjective results showed the body-axis display did not cause attitude confusion, a prior concern with this display. In the posttest comments, the pilots overwhelmingly selected the body-axis display as the display of choice.

  17. X-31 helmet-mounted visual and audio display (HMVAD) system

    NASA Astrophysics Data System (ADS)

    Boehmer, Steven C.

    1994-06-01

    Agile aircraft (X-29, X-31, F-18 High Alpha Research Vehicle and F-16 Multi-Axis Thrust Vector) test pilots, while flying at high angles of attack, experience difficulty predicting their flight path trajectory. To compensate for the loss of this critical element of situational awareness, the X-31 International Test Organization (ITO) installed and evaluated a helmet mounted display (HMD) system into an X-31 aircraft and simulator. Also investigated for incorporation within the HMD system and flight evaluation was another candidate technology for improving situational awareness -three dimensional audio. This was the first flight test evaluating the coupling of visual and audio cueing for aircrew aiding. The focus of the endeavor, which implemented two visual and audio formats, was to examine the extent visual and audio orientation cueing enhanced situational awareness and improved pilot performance during tactical flying. This paper provides an overview of the X-31 HMVAD system, describes the visual and audio symbology, presents a summary of the pilots' subjective evaluation of the system following its use in simulation and flight test, and outlines the future plans for the X-31 HMVAD system.

  18. Enhanced flight symbology for wide-field-of-view helmet-mounted displays

    NASA Astrophysics Data System (ADS)

    Rogers, Steven P.; Asbury, Charles N.; Szoboszlay, Zoltan P.

    2003-09-01

    A series of studies was conducted to improve the Army aviator's ability to perform night missions by developing innovative symbols that capitalize on the advantages of new wide field-of-view (WFOV) helmet-mounted displays (HMDs). The most important outcomes of the research were two new symbol types called the Cylinder and the Flight Path Predictor. The Cylinder provides a large symbolic representation of real-world orientation that enables pilots to maintain the world frame of reference even if the visibility of the world is lost due to dust, smoke, snow, or inadvertent instrument meteorological conditions (IMC). Furthermore, the Cylinder is peripherally presented, supporting the "ambient" visual mode so that it does not require the conscious attention of the viewer. The Flight Path Predictor was developed to show the predicted flight path of a maneuvering aircraft using earth-referenced HMD symbology. The experimental evidence and the pilot interview results show that the new HMD symbology sets are capable of preventing spatial disorientation, improving flight safety, enhancing flight maneuver precision, and reducing workload so that the pilot can more effectively perform the critical mission tasks.

  19. Symbology requirements in head-up and head-down displays for helicopters in NOE flight

    NASA Astrophysics Data System (ADS)

    Haidn, Hermann; Odendahl, Goetz

    1993-12-01

    In modern warfare scenarios military helicopters have to be able to operate in NoE envelopes under all meteorological conditions. Under daytime good weather conditions this poses no problem for well-trained aircrews. In nighttime or bad weather conditions however the use of electronic sensors like IIT or TI is necessary. The aircrew use these devices for obstacle detection and avoidance and flight attitude perception. Flight below tree top level is only feasible when both of these tasks can be accomplished safely throughout the whole flight. For this reason the pilots must fly visual at all times. Relying on instruments for flight attitude control when flying between the trees would surely result in the striking of obstacles. These facts and the necessity for the aircrew to view greater azimuth angles than fixed wing pilots imply differing equipment and symbology packages for the two aircraft species. As a matter of fact only helmet mounted displays are really useful for helicopter flight control symbology. The following are results of experience from a number of trials with symbology in helicopters in low level flight down to 10 feet at night with IITs.

  20. Low-cost day/night helmet-mounted displays (HMD) in airborne operations

    NASA Astrophysics Data System (ADS)

    Casey, Curtis J.

    1999-07-01

    Current doctrine dictates a requirement for conducting 24-hour operations on the modern battlefield either in a rural or urban environment. To date, Night Vision Goggles (NVGs) along with Infrared sensors provide the bulk of vision aids that allow crew members to engage in tactical operations at night and during periods of low and reduced visibility. Since operations employing these devices, as well as operational doctrine, require the crewmember to fly 'heads-out,' Heads-Up Displays (HUDs), enumerating flight parameters, engine and navigation information have come into existence, greatly reducing the workload on today's combat aviators. A fine example is the Marconi/Tracor ANVS-7. This device employs a symbol generator and CRT to project symbology of critical aircraft parameters into the Night Vision Goggle giving the aviator a HUD capability while engaged in NVG night operations. The system is limited to aided vision night operations employing NVGs. The same criteria that create a need for supplying critical flight information at night exist for day and night unaided vision operations. However, there is no system in production to answer this obvious need. There are several reasons for this: (1) Available technology that will offer a low-cost solution for days ops, (2) Ergonomic and Human factors Issues, (3) Competition with currently fielded systems (ANVS-7), (4) Cost. Highly sophisticated HMDs such as the Apache IHADSS and the Comanche HIDSS, which combine navigation, targeting as well as weapons and flight status for 24 hour, all-weather operations are far too expensive and, in many cases, inappropriate for the majority of Combat Support aircraft. Using internal R&D Kaiser Electronics has developed a low-cost HMD -- called Lite EyeTM HMD -- that is capable of being used in day and night operations that addresses the aforementioned issues. The solution, using recent advances in solid state display technology, maximizes the use of currently fielded equipment

  1. Color Helmet Mounted Display System with Real Time Computer Generated and Video Imagery for In-Flight Simulation

    NASA Technical Reports Server (NTRS)

    Sawyer, Kevin; Jacobsen, Robert; Aiken, Edwin W. (Technical Monitor)

    1995-01-01

    NASA Ames Research Center and the US Army are developing the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) using a Sikorsky UH-60 helicopter for the purpose of flight systems research. A primary use of the RASCAL is in-flight simulation for which the visual scene will use computer generated imagery and synthetic vision. This research is made possible in part to a full color wide field of view Helmet Mounted Display (HMD) system that provides high performance color imagery suitable for daytime operations in a flight-rated package. This paper describes the design and performance characteristics of the HMD system. Emphasis is placed on the design specifications, testing, and integration into the aircraft of Kaiser Electronics' RASCAL HMD system that was designed and built under contract for NASA. The optical performance and design of the Helmet mounted display unit will be discussed as well as the unique capabilities provided by the system's Programmable Display Generator (PDG).

  2. Fiber Optic Development For Use On The Fiber Optic Helmet Mounted Display

    NASA Astrophysics Data System (ADS)

    Thomas, Melvin L.; Siegmund, Walter P.; Antos, Steven E.; Robinson, Richard M.

    1989-09-01

    The Fiber Optic Helmet Mounted Display (FOHMD) developed by CAE for the US Air Force Human Resources Laboratory (AFHRL), requires very large format, coherant fiber optic cables. These cables must support the FOHMD's demanding modulation transfer function (MTF) requirements in full color and be flexible, durable, lightweight, and up to six feet long. These requirements have so constrained glass technology that conventional approaches are not capable of delivering the requisite performance. The cables currently used on FOHMD systems have alternating layers of inactive material to buffer linear arrays of multifibers so that a lighter weight 25 by 19 mm end size is achieved with 5 micron core size individual fibers. This skip-layer, multifiber approach delivers reasonable performance when using spectral multiplexing across the inactive layers. However, residual fixed pattern noise, broken multifibers, and inadequate resolution have reduced system performance. Because of the critical influence of the fiber optic cables on overall system performance, an alternative, but riskier process, is being explored. Several smaller experimental cables have been assembled using leachable, fused, multifibers arrayed in a hexagonal pattern. The inconspicuous mating of hexagonal elements should be possible now because of an order of magnitude improvement in cable drawing technology. Fused/leached fiber optic cables have the potential to provide image transmission capability equal to ten channels of the best available computer image generators. When coupled with chromatic enhancement to mask fixed pattern and broken fiber noise, the resulting MTF of the FOHMD optics would deliver a resolution equal to 1.5 arc minutes per pixel.

  3. Reading from a Head-Fixed Display during Walking: Adverse Effects of Gaze Stabilization Mechanisms

    PubMed Central

    Borg, Olivier; Casanova, Remy; Bootsma, Reinoud J.

    2015-01-01

    Reading performance during standing and walking was assessed for information presented on earth-fixed and head-fixed displays by determining the minimal duration during which a numerical time stimulus needed to be presented for 50% correct naming answers. Reading from the earth-fixed display was comparable during standing and walking, with optimal performance being attained for visual character sizes in the range of 0.2° to 1°. Reading from the head-fixed display was impaired for small (0.2-0.3°) and large (5°) visual character sizes, especially during walking. Analysis of head and eye movements demonstrated that retinal slip was larger during walking than during standing, but remained within the functional acuity range when reading from the earth-fixed display. The detrimental effects on performance of reading from the head-fixed display during walking could be attributed to loss of acuity resulting from large retinal slip. Because walking activated the angular vestibulo-ocular reflex, the resulting compensatory eye movements acted to stabilize gaze on the information presented on the earth-fixed display but destabilized gaze from the information presented on the head-fixed display. We conclude that the gaze stabilization mechanisms that normally allow visual performance to be maintained during physical activity adversely affect reading performance when the information is presented on a display attached to the head. PMID:26053622

  4. Reading from a Head-Fixed Display during Walking: Adverse Effects of Gaze Stabilization Mechanisms.

    PubMed

    Borg, Olivier; Casanova, Remy; Bootsma, Reinoud J

    2015-01-01

    Reading performance during standing and walking was assessed for information presented on earth-fixed and head-fixed displays by determining the minimal duration during which a numerical time stimulus needed to be presented for 50% correct naming answers. Reading from the earth-fixed display was comparable during standing and walking, with optimal performance being attained for visual character sizes in the range of 0.2° to 1°. Reading from the head-fixed display was impaired for small (0.2-0.3°) and large (5°) visual character sizes, especially during walking. Analysis of head and eye movements demonstrated that retinal slip was larger during walking than during standing, but remained within the functional acuity range when reading from the earth-fixed display. The detrimental effects on performance of reading from the head-fixed display during walking could be attributed to loss of acuity resulting from large retinal slip. Because walking activated the angular vestibulo-ocular reflex, the resulting compensatory eye movements acted to stabilize gaze on the information presented on the earth-fixed display but destabilized gaze from the information presented on the head-fixed display. We conclude that the gaze stabilization mechanisms that normally allow visual performance to be maintained during physical activity adversely affect reading performance when the information is presented on a display attached to the head.

  5. Reading from a Head-Fixed Display during Walking: Adverse Effects of Gaze Stabilization Mechanisms.

    PubMed

    Borg, Olivier; Casanova, Remy; Bootsma, Reinoud J

    2015-01-01

    Reading performance during standing and walking was assessed for information presented on earth-fixed and head-fixed displays by determining the minimal duration during which a numerical time stimulus needed to be presented for 50% correct naming answers. Reading from the earth-fixed display was comparable during standing and walking, with optimal performance being attained for visual character sizes in the range of 0.2° to 1°. Reading from the head-fixed display was impaired for small (0.2-0.3°) and large (5°) visual character sizes, especially during walking. Analysis of head and eye movements demonstrated that retinal slip was larger during walking than during standing, but remained within the functional acuity range when reading from the earth-fixed display. The detrimental effects on performance of reading from the head-fixed display during walking could be attributed to loss of acuity resulting from large retinal slip. Because walking activated the angular vestibulo-ocular reflex, the resulting compensatory eye movements acted to stabilize gaze on the information presented on the earth-fixed display but destabilized gaze from the information presented on the head-fixed display. We conclude that the gaze stabilization mechanisms that normally allow visual performance to be maintained during physical activity adversely affect reading performance when the information is presented on a display attached to the head. PMID:26053622

  6. A head-up display format for transport aircraft approach and landing

    NASA Technical Reports Server (NTRS)

    Bray, R. S.; Scott, B. C.

    1981-01-01

    An electronic flight-guidance display format was designed for use in evaluations of the collimated head-up display concept applied to transport aircraft landing. In the design process of iterative evaluation and modification, some general principles, or guidelines, applicable to electronic flight displays were suggested. The usefulness of an indication of instantaneous inertial flightpath was clearly demonstrated. Evaluator pilot acceptance of the unfamiliar display concepts was very positive when careful attention was given to indoctrination and training.

  7. Development of a head-mounted, eye-tracking system for dogs.

    PubMed

    Williams, Fiona J; Mills, Daniel S; Guo, Kun

    2011-01-15

    Growing interest in canine cognition and visual perception has promoted research into the allocation of visual attention during free-viewing tasks in the dog. The techniques currently available to study this (i.e. preferential looking) have, however, lacked spatial accuracy, permitting only gross judgements of the location of the dog's point of gaze and are limited to a laboratory setting. Here we describe a mobile, head-mounted, video-based, eye-tracking system and a procedure for achieving standardised calibration allowing an output with accuracy of 2-3°. The setup allows free movement of dogs; in addition the procedure does not involve extensive training skills, and is completely non-invasive. This apparatus has the potential to allow the study of gaze patterns in a variety of research applications and could enhance the study of areas such as canine vision, cognition and social interactions. PMID:21074562

  8. The impact of human factors, crashworthiness and optical performance design requirements on helmet-mounted display development from the 1970s to the present

    NASA Astrophysics Data System (ADS)

    Harding, Thomas H.; Rash, Clarence E.; McLean, William E.; Martin, John S.

    2015-05-01

    Driven by the operational needs of modern warfare, the helmet-mounted display (HMD) has matured from a revolutionary, but impractical, World War I era idea for an infantry marksman's helmet-mounted weapon delivery system to a sophisticated and ubiquitous display and targeting system that dominates current night warfighting operations. One of the most demanding applications for HMD designs has been in Army rotary-wing aviation, where HMDs offer greater direct access to visual information and increased situational awareness in an operational environment where information availability is critical on a second-to-second basis. However, over the past 40 years of extensive HMD development, a myriad of crashworthiness, optical, and human factors issues have both frustrated and challenged designers. While it may be difficult to attain a full consensus on which are the most important HMD design factors, certainly head-supported weight (HSW), exit pupil size, field-of-view, image resolution and physical eye relief have been among the most critical. A confounding factor has been the interrelationship between the many design issues, such as early attempts to use non-glass optical elements to lower HSW, but at the cost of image quality, and hence, pilot visual performance. This paper traces how the role of the demanding performance requirements placed on HMDs by the U.S. Army aviation community has impacted the progress of HMD designs towards the Holy Grail of HMD design: a wide field-of-view, high resolution, binocular, full-color, totally crashworthy system.

  9. Head-Mounted Eye Tracking of a Chimpanzee under Naturalistic Conditions

    PubMed Central

    Kano, Fumihiro; Tomonaga, Masaki

    2013-01-01

    This study offers a new method for examining the bodily, manual, and eye movements of a chimpanzee at the micro-level. A female chimpanzee wore a lightweight head-mounted eye tracker (60 Hz) on her head while engaging in daily interactions with the human experimenter. The eye tracker recorded her eye movements accurately while the chimpanzee freely moved her head, hands, and body. Three video cameras recorded the bodily and manual movements of the chimpanzee from multiple angles. We examined how the chimpanzee viewed the experimenter in this interactive setting and how the eye movements were related to the ongoing interactive contexts and actions. We prepared two experimentally defined contexts in each session: a face-to-face greeting phase upon the appearance of the experimenter in the experimental room, and a subsequent face-to-face task phase that included manual gestures and fruit rewards. Overall, the general viewing pattern of the chimpanzee, measured in terms of duration of individual fixations, length of individual saccades, and total viewing duration of the experimenter’s face/body, was very similar to that observed in previous eye-tracking studies that used non-interactive situations, despite the differences in the experimental settings. However, the chimpanzee viewed the experimenter and the scene objects differently depending on the ongoing context and actions. The chimpanzee viewed the experimenter’s face and body during the greeting phase, but viewed the experimenter’s face and hands as well as the fruit reward during the task phase. These differences can be explained by the differential bodily/manual actions produced by the chimpanzee and the experimenter during each experimental phase (i.e., greeting gestures, task cueing). Additionally, the chimpanzee’s viewing pattern varied depending on the identity of the experimenter (i.e., the chimpanzee’s prior experience with the experimenter). These methods and results offer new possibilities for

  10. Head-mounted eye tracking of a chimpanzee under naturalistic conditions.

    PubMed

    Kano, Fumihiro; Tomonaga, Masaki

    2013-01-01

    This study offers a new method for examining the bodily, manual, and eye movements of a chimpanzee at the micro-level. A female chimpanzee wore a lightweight head-mounted eye tracker (60 Hz) on her head while engaging in daily interactions with the human experimenter. The eye tracker recorded her eye movements accurately while the chimpanzee freely moved her head, hands, and body. Three video cameras recorded the bodily and manual movements of the chimpanzee from multiple angles. We examined how the chimpanzee viewed the experimenter in this interactive setting and how the eye movements were related to the ongoing interactive contexts and actions. We prepared two experimentally defined contexts in each session: a face-to-face greeting phase upon the appearance of the experimenter in the experimental room, and a subsequent face-to-face task phase that included manual gestures and fruit rewards. Overall, the general viewing pattern of the chimpanzee, measured in terms of duration of individual fixations, length of individual saccades, and total viewing duration of the experimenter's face/body, was very similar to that observed in previous eye-tracking studies that used non-interactive situations, despite the differences in the experimental settings. However, the chimpanzee viewed the experimenter and the scene objects differently depending on the ongoing context and actions. The chimpanzee viewed the experimenter's face and body during the greeting phase, but viewed the experimenter's face and hands as well as the fruit reward during the task phase. These differences can be explained by the differential bodily/manual actions produced by the chimpanzee and the experimenter during each experimental phase (i.e., greeting gestures, task cueing). Additionally, the chimpanzee's viewing pattern varied depending on the identity of the experimenter (i.e., the chimpanzee's prior experience with the experimenter). These methods and results offer new possibilities for examining

  11. A digital head-up display system as part of an integrated autonomous landing system concept

    NASA Astrophysics Data System (ADS)

    Wisely, Paul L.

    2008-04-01

    Considerable interest continues both in the aerospace industry and the military in the concept of autonomous landing guidance, and as previously reported, BAE Systems has been engaged for some time on an internally funded program to replace the high voltage power supply, tube and deflection amplifiers of its head up displays with an all digital solid state illuminated image system, based on research into the requirements for such a display as part of an integrated Enhanced Vision System. This paper describes the progress made to date in realising and testing a weather penetrating system incorporating an all digital head up display as its pilot-machine interface.

  12. Wearable and augmented reality displays using MEMS and SLMs

    NASA Astrophysics Data System (ADS)

    Urey, Hakan; Ulusoy, Erdem; Kazempourradi, Seyedmahdi M. K.; Mengu, Deniz; Olcer, Selim; Holmstrom, Sven T.

    2016-03-01

    In this talk, we present the various types of 3D displays, head-mounted projection displays and wearable displays developed in our group using MEMS scanners, compact RGB laser light sources, and spatial light modulators.

  13. Sound localization with head movement: implications for 3-d audio displays

    PubMed Central

    McAnally, Ken I.; Martin, Russell L.

    2014-01-01

    Previous studies have shown that the accuracy of sound localization is improved if listeners are allowed to move their heads during signal presentation. This study describes the function relating localization accuracy to the extent of head movement in azimuth. Sounds that are difficult to localize were presented in the free field from sources at a wide range of azimuths and elevations. Sounds remained active until the participants' heads had rotated through windows ranging in width of 2, 4, 8, 16, 32, or 64° of azimuth. Error in determining sound-source elevation and the rate of front/back confusion were found to decrease with increases in azimuth window width. Error in determining sound-source lateral angle was not found to vary with azimuth window width. Implications for 3-d audio displays: the utility of a 3-d audio display for imparting spatial information is likely to be improved if operators are able to move their heads during signal presentation. Head movement may compensate in part for a paucity of spectral cues to sound-source location resulting from limitations in either the audio signals presented or the directional filters (i.e., head-related transfer functions) used to generate a display. However, head movements of a moderate size (i.e., through around 32° of azimuth) may be required to ensure that spatial information is conveyed with high accuracy. PMID:25161605

  14. Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

    PubMed Central

    Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

    2016-01-01

    Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals. PMID:27731346

  15. A head-up display for low-visibility approach and landing

    NASA Technical Reports Server (NTRS)

    Bray, R. S.; Scott, B. C.

    1981-01-01

    An electronic flight-guidance display format was designed for use in evaluations of the collimated head-up display concept in low-visibility landings of transport aircraft. In the design process of iterative evaluation and modification, some general principles, or guidelines, applicable to such flight displays were suggested. The usefulness of an indication of instantaneous inertial flightpath was clearly demonstrated, particularly in low-altitude transition to visual references. Evaluator pilot acceptance of the unfamiliar display concepts was very positive when careful attention was given to indoctrination and training.

  16. Surgeon point-of-view recording: Using a high-definition head-mounted video camera in the operating room

    PubMed Central

    Nair, Akshay Gopinathan; Kamal, Saurabh; Dave, Tarjani Vivek; Mishra, Kapil; Reddy, Harsha S; Rocca, David Della; Rocca, Robert C Della; Andron, Aleza; Jain, Vandana

    2015-01-01

    Objective: To study the utility of a commercially available small, portable ultra-high definition (HD) camera (GoPro Hero 4) for intraoperative recording. Methods: A head mount was used to fix the camera on the operating surgeon's head. Due care was taken to protect the patient's identity. The recorded video was subsequently edited and used as a teaching tool. This retrospective, noncomparative study was conducted at three tertiary eye care centers. The surgeries recorded were ptosis correction, ectropion correction, dacryocystorhinostomy, angular dermoid excision, enucleation, blepharoplasty and lid tear repair surgery (one each). The recorded videos were reviewed, edited, and checked for clarity, resolution, and reproducibility. Results: The recorded videos were found to be high quality, which allowed for zooming and visualization of the surgical anatomy clearly. Minimal distortion is a drawback that can be effectively addressed during postproduction. The camera, owing to its lightweight and small size, can be mounted on the surgeon's head, thus offering a unique surgeon point-of-view. In our experience, the results were of good quality and reproducible. Conclusions: A head-mounted ultra-HD video recording system is a cheap, high quality, and unobtrusive technique to record surgery and can be a useful teaching tool in external facial and ophthalmic plastic surgery. PMID:26655001

  17. Head-Worn Display Concepts for Surface Operations for Commerical Aircraft

    NASA Technical Reports Server (NTRS)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Bailey, Randall E.; Shelton, Kevin J.; Williams, Steven P.; Kramer, Lynda J.; Norman, Robert M.

    2008-01-01

    Experiments and flight tests have shown that a Head-Up Display (HUD) and a head-down electronic moving map (EMM) can be enhanced with Synthetic Vision for airport surface operations. While great success in ground operations was demonstrated with a HUD, the research noted that two major HUD limitations during ground operations were its monochrome form and limited, fixed field-of-regard. A potential solution to these limitations found with HUDs may be emerging with Head Worn Displays (HWDs). HWDs are small display devices that may be worn without significant encumbrance to the user. By coupling the HWD with a head tracker, unlimited field-of-regard may be realized. The results of three ground simulation experiments conducted at NASA Langley Research Center are summarized. The experiments evaluated the efficacy of head-worn display applications of Synthetic Vision and Enhanced Vision technology to improve transport aircraft surface operations. The results of the experiments showed that the fully integrated HWD provided greater pilot performance with respect to staying on the path compared to using paper charts alone. Further, when comparing the HWD with the HUD concept, there were no differences in path performance. In addition, the HWD and HUD concepts were rated via paired-comparisons the same in terms of situation awareness and workload.

  18. An intelligent system and a relational data base for codifying helmet-mounted display symbology design requirements

    NASA Astrophysics Data System (ADS)

    Rogers, Steven P.; Hamilton, David B.

    1994-06-01

    To employ the most readily comprehensible presentation methods and symbology with helmet-mounted displays (HMDs), it is critical to identify the information elements needed to perform each pilot function and to analytically determine the attributes of these elements. The extensive analyses of mission requirements currently performed for pilot-vehicle interface design can be aided and improved by the new capabilities of intelligent systems and relational databases. An intelligent system, named ACIDTEST, has been developed specifically for organizing and applying rules to identify the best display modalities, locations, and formats. The primary objectives of the ACIDTEST system are to provide rapid accessibility to pertinent display research data, to integrate guidelines from many disciplines and identify conflicts among these guidelines, to force a consistent display approach among the design team members, and to serve as an 'audit trail' of design decisions and justifications. A powerful relational database called TAWL ORDIR has been developed to document information requirements and attributes for use by ACIDTEST as well as to greatly augment the applicability of mission analysis data. TAWL ORDIR can be used to rapidly reorganize mission analysis data components for study, perform commonality analyses for groups of tasks, determine the information content requirement for tailored display modes, and identify symbology integration opportunities.

  19. Alternative display and interaction devices

    NASA Technical Reports Server (NTRS)

    Bolas, M. T.; McDowall, I. E.; Mead, R. X.; Lorimer, E. R.; Hackbush, J. E.; Greuel, C.

    1995-01-01

    While virtual environment systems are typically thought to consist of a head mounted display and a flex-sensing glove, alternative peripheral devices are beginning to be developed in response to application requirements. Three such alternatives are discussed: fingertip sensing gloves, fixed stereoscopic viewers, and counterbalanced head mounted displays. A subset of commercial examples that highlight each alternative is presented as well as a brief discussion of interesting engineering and implementation issues.

  20. Helmet-mounted display (HMD) upgrade for the US Army's AVCATT simulation program

    NASA Astrophysics Data System (ADS)

    Melzer, James E.; Porter, James W.

    2008-04-01

    The Aviation Combined Arms Tactical Trainer (AVCATT) reconfigurable manned module simulator is the Army's premier deployable helicopter collective training simulator. While successful, improvements to the visual display performance for the Out-The-Window (OTW) visual system have been desired. In a recent selection evaluation, Rockwell Collins' SR100A HMD was chosen for the upgrade, improving display resolution, reducing weight, enhancing comfort and increasing ruggedness. This paper will compare the current XL100A HMD with the improved performance of the new SR100A system.

  1. A head-up display format for application to transport aircraft approach and landing

    NASA Technical Reports Server (NTRS)

    Bray, R. S.

    1980-01-01

    A head up display (HUD) format used in simulator studies of the application of HUD to the landing of civil transport aircraft is described in detail. The display features an indication of the aircraft's instantaneous flightpath that constitutes the primary controlled element. Discrete ILS error and altitude signals are scaled and positioned to provide precise guidance modes when tracked with the flightpath symbol. Consideration is given to both the availability and nonavailability of inertial velocity information in the aircraft.

  2. Comparison of two head-up displays in simulated standard and noise abatement night visual approaches

    NASA Technical Reports Server (NTRS)

    Cronn, F.; Palmer, E. A., III

    1975-01-01

    Situation and command head-up displays were evaluated for both standard and two segment noise abatement night visual approaches in a fixed base simulation of a DC-8 transport aircraft. The situation display provided glide slope and pitch attitude information. The command display provided glide slope information and flight path commands to capture a 3 deg glide slope. Landing approaches were flown in both zero wind and wind shear conditions. For both standard and noise abatement approaches, the situation display provided greater glidepath accuracy in the initial phase of the landing approaches, whereas the command display was more effective in the final approach phase. Glidepath accuracy was greater for the standard approaches than for the noise abatement approaches in all phases of the landing approach. Most of the pilots preferred the command display and the standard approach. Substantial agreement was found between each pilot's judgment of his performance and his actual performance.

  3. When Less Is Best: Female Brown-Headed Cowbirds Prefer Less Intense Male Displays

    PubMed Central

    O'Loghlen, Adrian L.; Rothstein, Stephen I.

    2012-01-01

    Sexual selection theory predicts that females should prefer males with the most intense courtship displays. However, wing-spread song displays that male brown-headed cowbirds (Molothrus ater) direct at females are generally less intense than versions of this display that are directed at other males. Because male-directed displays are used in aggressive signaling, we hypothesized that females should prefer lower intensity performances of this display. To test this hypothesis, we played audiovisual recordings showing the same males performing both high intensity male-directed and low intensity female-directed displays to females (N = 8) and recorded the females' copulation solicitation display (CSD) responses. All eight females responded strongly to both categories of playbacks but were more sexually stimulated by the low intensity female-directed displays. Because each pair of high and low intensity playback videos had the exact same audio track, the divergent responses of females must have been based on differences in the visual content of the displays shown in the videos. Preferences female cowbirds show in acoustic CSD studies are correlated with mate choice in field and captivity studies and this is also likely to be true for preferences elucidated by playback of audiovisual displays. Female preferences for low intensity female-directed displays may explain why male cowbirds rarely use high intensity displays when signaling to females. Repetitive high intensity displays may demonstrate a male's current condition and explain why these displays are used in male-male interactions which can escalate into physical fights in which males in poorer condition could be injured or killed. This is the first study in songbirds to use audiovisual playbacks to assess how female sexual behavior varies in response to variation in a male visual display. PMID:22567131

  4. Evaluation of Head-Worn Display Concepts for Commercial Aircraft Taxi Operations

    NASA Technical Reports Server (NTRS)

    Bailey, Randall E.; Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Kramer, Lynda J.

    2007-01-01

    Previous research has demonstrated that a Head-Up Display (HUD) can be used to enable more capacity and safer aircraft surface operations. This previous research also noted that the HUD exhibited two major limitations which hindered the full potential of the display concept: 1) the monochrome HUD format; and, 2) a limited, fixed field of regard. Full-color Head Worn Displays (HWDs) with very small sizes and weights are emerging to the extent that this technology may be practical for commercial and business aircraft operations. By coupling the HWD with a head tracker, full-color, out-the-window display concepts with an unlimited field-of-regard may be realized to improve efficiency and safety in surface operations. A ground simulation experiment was conducted at NASA Langley to evaluate the efficacy of head-worn display applications which may directly address the limitations of the HUD while retaining all of its advantages in surface operations. The simulation experiment used airline crews to evaluate various displays (HUD, HWD) and display concepts in an operationally realistic environment by using a Chicago, O Hare airport database. The results pertaining to the implications of HWDs for commercial business and transport aviation applications are presented herein. Overall HWD system latency was measured and found to be acceptable, but not necessarily optimal. A few occurrences of simulator sickness were noted while wearing the HWD, but overall there appears to be commercial pilot acceptability and usability to the concept. Many issues were identified which need to be addressed in future research including continued reduction in user encumbrance due to the HWD, and improvement in image alignment, accuracy, and boresighting.

  5. Evaluation of head-worn display concepts for commercial aircraft taxi operations

    NASA Astrophysics Data System (ADS)

    Bailey, Randall E.; Arthur, J. J., III; Prinzel, Lance, III; Kramer, Lynda J.

    2007-04-01

    Previous research has demonstrated that a Head-Up Display (HUD) can be used to enable more capacity and safer aircraft surface operations. This previous research also noted that the HUD exhibited two major limitations which hindered the full potential of the display concept: 1) the monochrome HUD format; and, 2) a limited, fixed field of regard. Full-color Head Worn Displays (HWDs) with very small sizes and weights are emerging to the extent that this technology may be practical for commercial and business aircraft operations. By coupling the HWD with a head tracker, full-color, out-the-window display concepts with an unlimited field-of-regard may be realized to improve efficiency and safety in surface operations. A ground simulation experiment was conducted at NASA Langley to evaluate the efficacy of head-worn display applications which may directly address the limitations of the HUD while retaining all of its advantages in surface operations. The simulation experiment used airline crews to evaluate various displays (HUD, HWD) and display concepts in an operationally realistic environment by using a Chicago, O'Hare airport database. The results pertaining to the implications of HWDs for commercial business and transport aviation applications are presented herein. Overall HWD system latency was measured and found to be acceptable, but not necessarily optimal. A few occurrences of simulator sickness were noted while wearing the HWD, but overall there appears to be commercial pilot acceptability and usability to the concept. Many issues were identified which need to be addressed in future research including continued reduction in user encumbrance due to the HWD, and improvement in image alignment, accuracy, and boresighting.

  6. Effect on real-world depth perception from exposure to heads-down stereoscopic flight displays

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Williams, Steven P.; Parrish, Russell V.

    1990-01-01

    A stereoacuity test was used as part of the experimental protocol of a study in which eight transport pilots flew repeated simulated landing approaches using both stereo and nonstereo three-dimensional heads-down 'pathway in the sky' displays. At the decisionmaking crux of each approach, the pilots transitioned to a stereoacuity test employing real objects rather than a two-dimensional target apparatus. A statistical analysis of stereoacuity measures which compared a controlled condition of no exposure to any electronic flight display with the transition data from nonstereo and stereopsis displays indicated no significant differences for any of the conditions.

  7. Ergonomic evaluation of ubiquitous computing with monocular head-mounted display

    NASA Astrophysics Data System (ADS)

    Kawai, Takashi; Häkkinen, Jukka; Yamazoe, Takashi; Saito, Hiroko; Kishi, Shinsuke; Morikawa, Hiroyuki; Mustonen, Terhi; Kaistinen, Jyrki; Nyman, Göte

    2010-01-01

    In this paper, the authors conducted an experiment to evaluate the UX in an actual outdoor environment, assuming the casual use of monocular HMD to view video content while short walking. In conducting the experiment, eight subjects were asked to view news videos on a monocular HMD while walking through a large shopping mall. Two types of monocular HMDs and a hand-held media player were used, and the psycho-physiological responses of the subjects were measured before, during, and after the experiment. The VSQ, SSQ and NASA-TLX were used to assess the subjective workloads and symptoms. The objective indexes were heart rate and stride and a video recording of the environment in front of the subject's face. The results revealed differences between the two types of monocular HMDs as well as between the monocular HMDs and other conditions. Differences between the types of monocular HMDs may have been due to screen vibration during walking, and it was considered as a major factor in the UX in terms of the workload. Future experiments to be conducted in other locations will have higher cognitive loads in order to study the performance and the situation awareness to actual and media environments.

  8. Jedi training: playful evaluation of head-mounted augmented reality display systems

    NASA Astrophysics Data System (ADS)

    Ozbek, Christopher S.; Giesler, Bjorn; Dillmann, Ruediger

    2004-05-01

    A fundamental decision in building augmented reality (AR) systems is how to accomplish the combining of the real and virtual worlds. Nowadays this key-question boils down to the two alternatives video-see-through (VST) vs. optical-see-through (OST). Both systems have advantages and disadvantages in areas like production-simplicity, resolution, flexibility in composition strategies, field of view etc. To provide additional decision criteria for high dexterity, accuracy tasks and subjective user-acceptance a gaming environment was programmed that allowed good evaluation of hand-eye coordination, and that was inspired by the Star Wars movies. During an experimentation session with more than thirty participants a preference for optical-see-through glasses in conjunction with infra-red-tracking was found. Especially the high-computational demand for video-capture, processing and the resulting drop in frame rate emerged as a key-weakness of the VST-system.

  9. Flight Test of a Head-Worn Display as an Equivalent-HUD for Terminal Operations

    NASA Technical Reports Server (NTRS)

    Shelton, K. J.; Arthur, J. J., III; Prinzel, L. J., III; Nicholas, S. N.; Williams, S. P.; Bailey, R. E.

    2015-01-01

    Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in the Next Generation Air Transportation System (NextGen). Under NASA's Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as a potential equivalent display to a Head-up Display (HUD). Title 14 of the US CFR 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent"' display combined with Enhanced Vision (EV). A successful HWD implementation may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A flight test was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Approach and taxi testing was performed on-board NASA's experimental King Air aircraft in various visual conditions. Preliminary quantitative results indicate the HWD tested provided equivalent HUD performance, however operational issues were uncovered. The HWD showed significant potential as all of the pilots liked the increased situation awareness attributable to the HWD's unique capability of unlimited field-of-regard.

  10. Flight test of a head-worn display as an equivalent-HUD for terminal operations

    NASA Astrophysics Data System (ADS)

    Shelton, K. J.; Arthur, J. J.; Prinzel, L. J.; Nicholas, S. N.; Williams, S. P.; Bailey, R. E.

    2015-05-01

    Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in the Next Generation Air Transportation System (NextGen). Under NASA's Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as a potential equivalent display to a Head-up Display (HUD). Title 14 of the US CFR 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent"' display combined with Enhanced Vision (EV). A successful HWD implementation may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A flight test was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Approach and taxi testing was performed on-board NASA's experimental King Air aircraft in various visual conditions. Preliminary quantitative results indicate the HWD tested provided equivalent HUD performance, however operational issues were uncovered. The HWD showed significant potential as all of the pilots liked the increased situation awareness attributable to the HWD's unique capability of unlimited field-of-regard.

  11. Visual Acuity Using Head-fixed Displays During Passive Self and Surround Motion

    NASA Technical Reports Server (NTRS)

    Wood, Scott J.; Black, F. Owen; Stallings, Valerie; Peters, Brian

    2007-01-01

    The ability to read head-fixed displays on various motion platforms requires the suppression of vestibulo-ocular reflexes. This study examined dynamic visual acuity while viewing a head-fixed display during different self and surround rotation conditions. Twelve healthy subjects were asked to report the orientation of Landolt C optotypes presented on a micro-display fixed to a rotating chair at 50 cm distance. Acuity thresholds were determined by the lowest size at which the subjects correctly identified 3 of 5 optotype orientations at peak velocity. Visual acuity was compared across four different conditions, each tested at 0.05 and 0.4 Hz (peak amplitude of 57 deg/s). The four conditions included: subject rotated in semi-darkness (i.e., limited to background illumination of the display), subject stationary while visual scene rotated, subject rotated around a stationary visual background, and both subject and visual scene rotated together. Visual acuity performance was greatest when the subject rotated around a stationary visual background; i.e., when both vestibular and visual inputs provided concordant information about the motion. Visual acuity performance was most reduced when the subject and visual scene rotated together; i.e., when the visual scene provided discordant information about the motion. Ranges of 4-5 logMAR step sizes across the conditions indicated the acuity task was sufficient to discriminate visual performance levels. The background visual scene can influence the ability to read head-fixed displays during passive motion disturbances. Dynamic visual acuity using head-fixed displays can provide an operationally relevant screening tool for visual performance during exposure to novel acceleration environments.

  12. High-resolution LCD projector for extra-wide-field-of-view head-up display

    NASA Astrophysics Data System (ADS)

    Brown, Robert D.; Modro, David H.; Quast, Gerhardt A.; Wood, Robert B.

    2003-09-01

    LCD projection-based cockpit displays are beginning to make entry into military and commercial aircraft. Customers for commercial Head-Up Displays (HUDs)(including airframe manufacturers) are now interested in the adaptation of the technology into existing and future HUD optical systems. LCD projection can improve mean-time-between-failure rates because the LCDs are very robust and the light sources can be replaced with scheduled maintenance by the customer without the need for re-calibration. LCD projectors promise to lower the cost of the HUD because the cost of these displays continues to drop while the cost of CRTs remain stable. LCD projectors provide the potential for multi-colors, higher brightness raster, and all-digital communication between the flight computer and display unit. Another potential benefit of LCD projection is the ability to increase field of view and viewing eyebox without exceeding existing power budgets or reducing display lifetime and reliability compared to the capabilities provided by CRTs today. This paper describes the performance requirements and improved performance of a third-generation LCD projection image source for use in a wide field of view head-up display (HUD) optical system. This paper will focus on new HUD requirements and the application of various technologies such as LCOS microdisplays, arc lamps, and rear-projection screens. Measured performance results are compared to the design requirements.

  13. Simulation evaluation of a low-altitude helicopter flight guidance system adapted for a helmet-mounted display

    NASA Technical Reports Server (NTRS)

    Swenson, Harry N.; Zelenka, Richard E.; Hardy, Gordon H.; Dearing, Munro G.

    1991-01-01

    A computer aiding concept for low-altitude helicopter flight has been developed and evaluated in a real-time piloted simulation. The concept included an optimal control trajectory-generation algorithm based upon dynamic programming, and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The pilot evaluation was conducted at the NASA-Ames Research Center moving base vertical motion simulator (VMS) by pilots representing NASA, the US Army, Air Force, and helicopter industry. The pilot manually tracked the trajectory generated by the algorithm utilizing the HMD symbology. The pilots were able to satisfactorily perform the tracking tasks while maintaining a high degree of awareness of the outside world.

  14. Head-up display using an inclined Al2O3 column array.

    PubMed

    Cho, Wen-Hao; Lee, Chao-Te; Kei, Chi-Chung; Liao, Bo-Huei; Chiang, Donyau; Lee, Cheng-Chung

    2014-02-01

    An orderly inclined Al2O3 column array was fabricated by atomic layer deposition and sequential electron beam evaporation using a hollow nanosphere template. The transmittance spectra at various angles of incidence were obtained through the use of a Perkin-Elmer Lambda 900 UV/VIS/NIR spectrometer. The inclined column array could display the image information through a scattering mechanism and was transparent at high viewing angles along the deposition plane. This characteristic of the inclined column array gives it potential for applications in head-up displays in the automotive industry.

  15. Head-Up Auditory Displays for Traffic Collision Avoidance System Advisories: A Preliminary Investigation

    NASA Technical Reports Server (NTRS)

    Begault, Durand R.

    1993-01-01

    The advantage of a head-up auditory display was evaluated in a preliminary experiment designed to measure and compare the acquisition time for capturing visual targets under two auditory conditions: standard one-earpiece presentation and two-earpiece three-dimensional (3D) audio presentation. Twelve commercial airline crews were tested under full mission simulation conditions at the NASA-Ames Man-Vehicle Systems Research Facility advanced concepts flight simulator. Scenario software generated visual targets corresponding to aircraft that would activate a traffic collision avoidance system (TCAS) aural advisory; the spatial auditory position was linked to the visual position with 3D audio presentation. Results showed that crew members using a 3D auditory display acquired targets approximately 2.2 s faster than did crew members who used one-earpiece head- sets, but there was no significant difference in the number of targets acquired.

  16. Project plan for joint FAA/NASA head-up display concept evaluation

    NASA Technical Reports Server (NTRS)

    Haines, R. F.

    1978-01-01

    Head-Up Display (HUD) concept for large commercial turbojet transport aircraft is considered for the its contribution to aviation safety in the form of improved performance during the approach and landing phase flight. The basic reearch areas represent fundamental questions that are still unresolved and which were considered important to the effective use of the HUD by pilots. Project documentation and management responsibilities are outlined.

  17. Synthetic Vision Enhanced Surface Operations With Head-Worn Display for Commercial Aircraft

    NASA Technical Reports Server (NTRS)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Shelton, Kevin J.; Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Norman, R. M.

    2007-01-01

    Experiments and flight tests have shown that airport surface operations can be enhanced by using synthetic vision and associated technologies, employed on a Head-Up Display (HUD) and head-down display electronic moving maps (EMM). Although HUD applications have shown the greatest potential operational improvements, the research noted that two major limitations during ground operations were its monochrome form and limited, fixed field-of-regard. A potential solution to these limitations may be the application of advanced Head Worn Displays (HWDs) particularly during low-visibility operations wherein surface movement is substantially limited because of the impaired vision of pilots and air traffic controllers. The paper describes the results of ground simulation experiments conducted at the NASA Langley Research Center. The results of the experiments showed that the fully integrated HWD concept provided significantly improved path performance compared to using paper charts alone. When comparing the HWD and HUD concepts, there were no statistically-significant differences in path performance or subjective ratings of situation awareness and workload. Implications and directions for future research are described.

  18. Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results

    NASA Technical Reports Server (NTRS)

    Hughes, Monica F.; Glaab, Louis J.

    2007-01-01

    A critical component of SVS displays is the appropriate presentation of terrain to the pilot. At the time of this study, the relationship between the complexity of the terrain presentation and resulting enhancements of pilot SA and pilot performance had been largely undefined. The terrain portrayal for SVS head-down displays (TP-HDD) simulation examined the effects of two primary elements of terrain portrayal on the primary flight display (PFD): variations of digital elevation model (DEM) resolution and terrain texturing. Variations in DEM resolution ranged from sparsely spaced (30 arc-sec) to very closely spaced data (1 arc-sec). Variations in texture involved three primary methods: constant color, elevation-based generic, and photo-realistic, along with a secondary depth cue enhancer in the form of a fishnet grid overlay.

  19. High brightness MEMS mirror based head-up display (HUD) modules with wireless data streaming capability

    NASA Astrophysics Data System (ADS)

    Milanovic, Veljko; Kasturi, Abhishek; Hachtel, Volker

    2015-02-01

    A high brightness Head-Up Display (HUD) module was demonstrated with a fast, dual-axis MEMS mirror that displays vector images and text, utilizing its ~8kHz bandwidth on both axes. Two methodologies were evaluated: in one, the mirror steers a laser at wide angles of <48° on transparent multi-color fluorescent emissive film and displays content directly on the windshield, and in the other the mirror displays content on reflective multi-color emissive phosphor plates reflected off the windshield to create a virtual image for the driver. The display module is compact, consisting of a single laser diode, off-the-shelf lenses and a MEMS mirror in combination with a MEMS controller to enable precise movement of the mirror's X- and Y-axis. The MEMS controller offers both USB and wireless streaming capability and we utilize a library of functions on a host computer for creating content and controlling the mirror. Integration with smart phone applications is demonstrated, utilizing the mobile device both for content generation based on various messages or data, and for content streaming to the MEMS controller via Bluetooth interface. The display unit is highly resistant to vibrations and shock, and requires only ~1.5W to operate, even with content readable in sunlit outdoor conditions. The low power requirement is in part due to a vector graphics approach, allowing the efficient use of laser power, and also due to the use of a single, relatively high efficiency laser and simple optics.

  20. System for providing an integrated display of instantaneous information relative to aircraft attitude, heading, altitude, and horizontal situation

    NASA Technical Reports Server (NTRS)

    James, R. (Inventor)

    1981-01-01

    A display device is disclosed which is particularly suited for providing the pilot of an aircraft with combined inflight attitude, heading, altitude, and horizontal situation information previously available only by using two or three devices providing separate displays. The preferred embodiment combines a commonly used and commercially available flight director-type device for providing a display in combination with a miniature aircraft supported for angular displacement from a vertical orientation to indicate heading error, or heading offset, and an extended course deviation indicator bar which projects into juxtaposition with the miniature aircraft for providing a true picture of the aircraft's horizontal situation relative to a selective VOR, ILS, or MLS course.

  1. Simulation evaluation of a low-altitude helicopter flight guidance system adapted for a helmet-mounted display

    NASA Technical Reports Server (NTRS)

    Swenson, Harry N.; Zelenka, Richard E.; Hardy, Gordon H.; Dearing, Munro G.

    1992-01-01

    A computer aiding concept for low-altitude helicopter flight was developed and evaluated in a real-time piloted simulation. The concept included an optimal control trajectory-generation algorithm based upon dynamic programming and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and advanced navigation information to determine a trajectory between mission way points that seeks valleys to minimize threat exposure. The pilot evaluation was conducted at NASA ARC moving base Vertical Motion Simulator (VMS) by pilots representing NASA, the U.S. Army, the Air Force, and the helicopter industry. The pilots manually tracked the trajectory generated by the algorithm utilizing the HMD symbology. The pilots were able to satisfactorily perform the tracking tasks while maintaining a high degree of awareness of the outside world.

  2. Subjective results of a simulator evaluation using synthetic terrain imagery presented on a helmet-mounted display

    NASA Astrophysics Data System (ADS)

    Rate, Christopher R.; Probert, Andrew; Wright, David; Corwin, William H.; Royer, Rick

    1994-06-01

    Combat mission scenarios require pilots to maneuver their aircraft over and around various terrain features at high speeds and low altitudes day, night, or in adverse meteorological conditions. While current systems (e.g., Night Vision Goggles and FLIR) provide some support for the pilot, they are not adequate in many weather conditions. However, the effects of adverse weather can be overcome using the U. S. Defense Mapping Agency's digital terrain elevation database to create a synthetic terrain image (STI). The concept of synthetically derived terrain imagery, projected as background on a Helmet-Mounted Display, was investigated in regards to its utility for enhancing pilot terrain awareness. An initial study using four Lockheed pilots and six USAF pilots was conducted to determine subjective preference of STI formats. A follow-on study, using two preferred formats, evaluated STI in a full-mission simulation environment. Six F-16 pilots completed a half day of training and a one day evaluation. Data was collected on missions involving low level navigation, followed by a laser guided bomb loft or offset roll- in dive bomb attack. Thirteen missions per pilot were completed including bomb runs using LANTIRN without STI. All the runs were at night with either 'poor' or 'good' FLIR conditions over rough or moderately rolling terrain. The evaluation indicated that pilots found STI to be useful and offered real-time support for low level navigation. Some problems still exist (e.g., field of view of HMD), which will be investigated in future studies.

  3. Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results: Compilation of Pilot Transcripts

    NASA Technical Reports Server (NTRS)

    Hughes, Monica F.; Glaab, Louis J.

    2007-01-01

    The Terrain Portrayal for Head-Down Displays (TP-HDD) simulation experiment addressed multiple objectives involving twelve display concepts (two baseline concepts without terrain and ten synthetic vision system (SVS) variations), four evaluation maneuvers (two en route and one approach maneuver, plus a rare-event scenario), and three pilot group classifications. The TP-HDD SVS simulation was conducted in the NASA Langley Research Center's (LaRC's) General Aviation WorkStation (GAWS) facility. The results from this simulation establish the relationship between terrain portrayal fidelity and pilot situation awareness, workload, stress, and performance and are published in the NASA TP entitled Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results. This is a collection of pilot comments during each run of the TP-HDD simulation experiment. These comments are not the full transcripts, but a condensed version where only the salient remarks that applied to the scenario, the maneuver, or the actual research itself were compiled.

  4. Some VTOL head-up display drive-law problems and solutions

    NASA Technical Reports Server (NTRS)

    Merrick, Vernon K.

    1993-01-01

    A piloted simulation test was conducted on the Ames Research Center's vertical motion simulator (VMS) in support of the Phase 2A flight test of NASA's V/STOL systems research aircraft (VSRA). During the simulation several problems were found with the head-up display (HUD) symbol drive laws and the flightpath synthesis. These problems and the solutions devised to solve them are described. Most of the resulting HUD drive-law changes were implemented during the simulation and their effectiveness was verified. Subsequently both the HUD symbol drive-law and flightpath-synthesis changes were implemented in the VSRA and tested successfully in the Phase 2A flight tests.

  5. An exploratory simulation study of a head-up display for general aviation lightplanes

    NASA Technical Reports Server (NTRS)

    Harris, R. L., Sr.; Hewes, D. E.

    1973-01-01

    The concept of a simplified head-up display referred to as a landing-site indicator (LASI) for use in lightplanes is discussed. Results of a fixed-base simulation study exploring the feasibility of the LASI concept are presented in terms of measurements of pilot performance, control-activity parameters, and subjective comments of four test subjects. These subjects, all of whom had various degrees of piloting experience in this type aircraft, performed a series of simulated landings both with and without the LASI starting from different initial conditions in the final approach leg of the landing maneuver.

  6. A head-up display for mid-air drone recovery

    NASA Technical Reports Server (NTRS)

    Augustine, W. L.; Heft, E. L.; Bowen, T. E.; Newman, R. L.

    1978-01-01

    During mid-air retrieval of parachute packages, the absence of a natural horizon creates serious difficulties for the pilot of the recovery helicopter. A head-up display (HUD) was tested in an attempt to solve this problem. Both a roll-stabilized HUD and a no-roll (pitch only) HUD were tested. The results show that fewer missed passes occurred with the roll-stabilized HUD when the horizon was obscured. The pilots also reported that the workload was greatly reduced. Roll-stabilization was required to prevent vertigo when flying in the absence of a natural horizon. Any HUD intended for mid-air retrieval should display pitch, roll, sideslip, airspeed, and vertical velocity.

  7. Night visual approaches: Pilot performance with and without a head-up display

    NASA Technical Reports Server (NTRS)

    Palmer, E. A.

    1972-01-01

    Simulated night visual approaches were flown into two airports with and without a head up display (HUD) in a transport aircraft. The HUD featured pitch stabilized vertical scales which displayed the glide slope angle to the runway aim point and a horizontal bar which aided the pilot in his control of the aircraft flight path angle. One airport was located on flat terrain with numerous foreground lights, the second airport had no foreground lights and the terrain sloped up behind the airport. With the HUD glide slope tracking precision was equally good for either runway. With no HUD glide slope tracking was about three times worse with the flat airport and about eight times worse with the airport with no foreground lights and up-sloping terrain beyond the runway.

  8. An evaluation of head-up displays in civil transport operations

    NASA Technical Reports Server (NTRS)

    Lauber, J. K.; Bray, R. S.; Scott, B. C.

    1981-01-01

    To determine the advantages and disadvantages of head-up displays (HUD) in civil transport approach and landing operations, an operational evaluation was conducted on the flight simulator for advanced aircraft at Ames. A non-conformal HUD concept which contained raw data and Flight Director command information, and a conformal, flight path HUD concept was designed to permit terminal area maneuvering, intercept, final approach, flare, and landing operations. Twelve B-727 line pilots (Captains) flew a series of precision and non-precision approaches under a variety of environmental and operational conditions, including wind shear, turbulence and low ceilings and visibilities. A preliminary comparison of various system and pilot performance measures as a function of display type (Flight Director HUD, Flight Path HUD, or No HUD) indicates improvements in precision and accuracy of aircraft flight path control when using the HUDs. The results also demonstrated some potentially unique advantages of a flight path HUD during non-precision approaches.

  9. Wide-screen autostereoscopic display system employing head-position tracking

    NASA Astrophysics Data System (ADS)

    Tetsutani, Nobuji; Omura, Katsuyuki; Kishino, Fumio

    1994-11-01

    We propose a head-tracking autostereoscopic display system based on magnetic-sensor tracking of the viewer's side-to-side location, and optical slewing of a stereoscopic image-pair array projected onto a lenticular screen so as to keep the images received by the viewer's eyes distinct. Viewer distance changes are accommodated by slight magnification changes of the projected image array. A high-definition-TV LCD projector is used with a 178-cm (70-in.) lenticular sheet (diagonal measurement) to provide impressive computer-generated 3D images over a particularly wide viewing zone. The system finds application in a virtual-space teleconferencing system that requires a large-scale stereoscopic display without the use of special viewing glasses.

  10. A head up display format for application to V/STOL aircraft approach and landing

    NASA Technical Reports Server (NTRS)

    Merrick, Vernon K.; Farris, Glenn G.; Vanags, Andrejs A.

    1990-01-01

    A head up display (HUD) format developed at NASA Ames Research Center to provide pilots of V/STOL aircraft with complete flight guidance and control information for category-3C terminal-area flight operations, is described in detail. These flight operations cover a large spectrum, from STOL operations on land-based runways to VTOL operations on small ships in high seas. Included in this description is a complete geometrical specification of the HUD elements and their drive laws. The principal features of this display format are the integration of the flightpath and pursuit guidance information into a narrow field of view, easily assimilated by the pilot with a single glance, and the superposition of vertical and horizontal situation information. The display is a derivative of a successful design developed for conventional transport aircraft. The design is the outcome of many piloted simulations conducted over a four-year period. Whereas the concepts on which the display format rests could not be fully exploited because of field-of-view restrictions, and some reservations remain about the acceptability of superimposing vertical and horizontal situation information, the design successfully fulfilled its intended objectives.

  11. Advanced Pathway Guidance Evaluations on a Synthetic Vision Head-Up Display

    NASA Technical Reports Server (NTRS)

    Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

    2005-01-01

    NASA's Synthetic Vision Systems (SVS) project is developing technologies with practical applications to potentially eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced guidance for commercial and business aircraft. This experiment evaluated the influence of different pathway and guidance display concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two pathway formats (dynamic and minimal tunnel presentations) were evaluated against a baseline condition (no tunnel) during simulated instrument meteorological conditions approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

  12. Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography

    PubMed Central

    Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S.; Kuo, Anthony N.; Toth, Cynthia A.; Izatt, Joseph A.

    2016-01-01

    Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

  13. Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography.

    PubMed

    Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S; Kuo, Anthony N; Toth, Cynthia A; Izatt, Joseph A

    2016-05-01

    Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

  14. THE EFFECTS ON DRIVING SPEED OF A HEAD-UP DISPLAY OF ROAD WARNINGS (1).

    PubMed

    Huang, Cheng-Hung; Chao, Chun-Wen

    2015-10-01

    This study investigated the superimposition of the projected markings on the road with head-up display, as well as their effects on the driver's speed. Two experiments were conducted. In Exp. 1, driving operations were simulated with a desktop computer to assess 18 deceleration markings (from the factors position, shape, and color) and determined the factors and levels influencing driving speeds. Based on the results of Exp. 1, six deceleration markings (from the factors shape and color) were selected in the driving simulator for conducting Exp. 2. The results of Exp. 1 showed that markings at the sides were better than the markings in the center. In Exp. 2, there was no significant difference between the effects of the arrangement of markings and the change of shape and color on driving stability. Yellow and white colors had no significant effect on speed; however, bar markings were better than zigzag markings. The results indicated that the projection of markings on a head-up display was helpful for indicating necessary deceleration. PMID:26474437

  15. RatCAP: a small, head-mounted PET tomograph for imaging the brain of an awake RAT

    NASA Astrophysics Data System (ADS)

    Woody, C.; Kriplani, A.; O'Connor, P.; Pratte, J.-F.; Radeka, V.; Rescia, S.; Schlyer, D.; Shokouhi, S.; Stoll, S.; Vaska, P.; Villaneuva, A.; Volkow, N.; Yu, B.

    2004-07-01

    A small, head-mounted tomograph is being developed which will allow PET imaging of the brain of an awake rat. This device will permit neurophysiological studies to be carried out on small animals without the use of anaesthesia, which severely suppresses brain functions and behavior. The tomograph consists of a 4 cm diameter ring consisting of 12 blocks of LSO crystals, each containing a 4×8 matrix of 2×2 mm 2 pixels read out with a Hamamatsu S8550 avalanche photodiode array. The ring will be mounted to the head of the rat and supported by a tether that carries the weight and provides a pathway for electrical signals. Combined with additional mechanical components, it will allow nearly complete freedom of movement of the animal. In order to minimize the weight of the ring, and to keep all of the front end readout electronics as close as possible to the detector, a new ASIC is being developed in 0.18 μm CMOS technology that will process the analog signals and provide digital readout of the pixel arrays and timing information. This paper will describe the novel features and challenges of this new detector, along with preliminary results obtained with a pair of block detectors used in a configuration similar to the final tomograph. Results are given on studies carried out to optimize the light output of the crystal arrays, measurements of the APDs, a preliminary design of the readout electronics chip, and reconstructed images of various types of phantoms in order to demonstrate the feasibility of the detector concept.

  16. Helmet-Mounted Display Research Capabilities of the NASA/Army Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL)

    NASA Technical Reports Server (NTRS)

    Jacobsen, R. A.; Bivens, C. C.; Rediess, N. A.; Hindson, W. S.; Aiken, E. W.; Aiken, Edwin W. (Technical Monitor)

    1995-01-01

    The Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) is a UH-60A Black Hawk helicopter that is being modified by the US Army and NASA for flight systems research. The principal systems that are being installed in the aircraft are a Helmet Mounted Display (HMD) and imaging system, and a programmable full authority Research Flight Control System (RFCS). In addition, comprehensive instrumentation of both the rigid body of the helicopter and the rotor system is provided. The paper will describe the capabilities of these systems and their current state of development. A brief description of initial research applications is included. The wide (40 X 60 degree) field-of-view HMD system has been provided by Kaiser Electronics. It can be configured as a monochromatic system for use in bright daylight conditions, a two color system for darker ambients, or a full color system for use in night viewing conditions. Color imagery is achieved using field sequential video and a mechanical color wheel. In addition to the color symbology, high resolution computer-gene rated imagery from an onboard Silicon Graphics Reality Engine Onyx processor is available for research in virtual reality applications. This synthetic imagery can also be merged with real world video from a variety of imaging systems that can be installed easily on the front of the helicopter. These sensors include infrared or tv cameras, or potentially small millimeter wave radars. The Research Flight Control System is being developed for the aircraft by a team of contractors led by Boeing Helicopters. It consists of a full authority high bandwidth fly-by-wire actuators that drive the main rotor swashplate actuators and the tail rotor actuator in parallel. This arrangement allows the basic mechanical flight control system of the Black Hawk to be retained so that the safety pilot can monitor the operation of the system through the action of his own controls. The evaluation pilot will signal the fly

  17. Head-up displays: Effect of information location on the processing of superimposed symbology

    NASA Technical Reports Server (NTRS)

    Sanford, Beverly D.; Foyle, David C.; Mccann, Robert S.; Jordan, Kevin

    1993-01-01

    Head-up display (HUD) symbology superimposes vehicle status information onto the external terrain, providing simultaneous visual access to both sources of information. Relative to a baseline condition in which the superimposed altitude indicator was omitted, altitude maintenance was improved by the presence of the altitude indicator, and this improvement was the same magnitude regardless of the position of the altitude indicator on the screen. However, a concurrent decifit in heading maintenance was observed only when the altitude indicator was proximal to the path information. These results did not support a model of the concurrent processing deficit based on an inability to attend to multiple locations in parallel. They are consistent with previous claims that the deficit is the product of attentional limits on subjects' ability to process two separate objects (HUD symbology and terrain information) concurrently. The absence of a performance tradeoff when the HUD and the path information were less proximal is attributed to a breaking of attentional tunneling on the HUD, possibly due to eye movements.

  18. An externally head-mounted wireless neural recording device for laboratory animal research and possible human clinical use.

    PubMed

    Yin, Ming; Li, Hao; Bull, Christopher; Borton, David A; Aceros, Juan; Larson, Lawrence; Nurmikko, Arto V

    2013-01-01

    In this paper we present a new type of head-mounted wireless neural recording device in a highly compact package, dedicated for untethered laboratory animal research and designed for future mobile human clinical use. The device, which takes its input from an array of intracortical microelectrode arrays (MEA) has ninety-seven broadband parallel neural recording channels and was integrated on to two custom designed printed circuit boards. These house several low power, custom integrated circuits, including a preamplifier ASIC, a controller ASIC, plus two SAR ADCs, a 3-axis accelerometer, a 48MHz clock source, and a Manchester encoder. Another ultralow power RF chip supports an OOK transmitter with the center frequency tunable from 3GHz to 4GHz, mounted on a separate low loss dielectric board together with a 3V LDO, with output fed to a UWB chip antenna. The IC boards were interconnected and packaged in a polyether ether ketone (PEEK) enclosure which is compatible with both animal and human use (e.g. sterilizable). The entire system consumes 17mA from a 1.2Ahr 3.6V Li-SOCl2 1/2AA battery, which operates the device for more than 2 days. The overall system includes a custom RF receiver electronics which are designed to directly interface with any number of commercial (or custom) neural signal processors for multi-channel broadband neural recording. Bench-top measurements and in vivo testing of the device in rhesus macaques are presented to demonstrate the performance of the wireless neural interface.

  19. An externally head-mounted wireless neural recording device for laboratory animal research and possible human clinical use.

    PubMed

    Yin, Ming; Li, Hao; Bull, Christopher; Borton, David A; Aceros, Juan; Larson, Lawrence; Nurmikko, Arto V

    2013-01-01

    In this paper we present a new type of head-mounted wireless neural recording device in a highly compact package, dedicated for untethered laboratory animal research and designed for future mobile human clinical use. The device, which takes its input from an array of intracortical microelectrode arrays (MEA) has ninety-seven broadband parallel neural recording channels and was integrated on to two custom designed printed circuit boards. These house several low power, custom integrated circuits, including a preamplifier ASIC, a controller ASIC, plus two SAR ADCs, a 3-axis accelerometer, a 48MHz clock source, and a Manchester encoder. Another ultralow power RF chip supports an OOK transmitter with the center frequency tunable from 3GHz to 4GHz, mounted on a separate low loss dielectric board together with a 3V LDO, with output fed to a UWB chip antenna. The IC boards were interconnected and packaged in a polyether ether ketone (PEEK) enclosure which is compatible with both animal and human use (e.g. sterilizable). The entire system consumes 17mA from a 1.2Ahr 3.6V Li-SOCl2 1/2AA battery, which operates the device for more than 2 days. The overall system includes a custom RF receiver electronics which are designed to directly interface with any number of commercial (or custom) neural signal processors for multi-channel broadband neural recording. Bench-top measurements and in vivo testing of the device in rhesus macaques are presented to demonstrate the performance of the wireless neural interface. PMID:24110386

  20. Optical effects of F-16 Canopy-HUD (Head-Up Display) integration

    NASA Astrophysics Data System (ADS)

    Task, H. L.

    1983-12-01

    The F-16 heads-up display (HUD) provides the pilot with visual information in symbology form that is overlayed on the outside world scene in the forward viewing direction. This super-position of HUD symbology and outside world scene is done by using an optical combiner (beamsplitter) which is part of the HUD optical system. One of the critical items of information that is displayed on the HUD is the aiming reticle that is used for air-to-air and air-to-ground weapon aiming. In order to be effective, it is essential that the aiming reticle be accurately boresighted to the weapon system. This requires a careful integration of the optical characteristics of the HUD and the aircraft canopy. There are several optical parameters that can affect target acquisition and aiming accuracy that involve the canopy, the HUD, and interactions between the two. The primary parameter that affects aiming accuracy is angular deviation due to the windscreen and/or the HUD.

  1. Chronic monitoring of cortical hemodynamics in behaving, freely-moving rats using a miniaturized head-mounted optical microscope

    NASA Astrophysics Data System (ADS)

    Sigal, Iliya; Gad, Raanan; Koletar, Margaret; Ringuette, Dene; Stefanovic, Bojana; Levi, Ofer

    2016-03-01

    Growing interest within the neurophysiology community in assessing healthy and pathological brain activity in animals that are awake and freely-behaving has triggered the need for optical systems that are suitable for such longitudinal studies. In this work we report label-free multi-modal imaging of cortical hemodynamics in the somatosensory cortex of awake, freely-behaving rats, using a novel head-mounted miniature optical microscope. The microscope employs vertical cavity surface emitting lasers (VCSELs) at three distinct wavelengths (680 nm, 795 nm, and 850 nm) to provide measurements of four hemodynamic markers: blood flow speeds, HbO, HbR, and total Hb concentration, across a > 2 mm field of view. Blood flow speeds are extracted using Laser Speckle Contrast Imaging (LSCI), while oxygenation measurements are performed using Intrinsic Optical Signal Imaging (IOSI). Longitudinal measurements on the same animal are made possible over the course of > 6 weeks using a chronic window that is surgically implanted into the skull. We use the device to examine changes in blood flow and blood oxygenation in superficial cortical blood vessels and tissue in response to drug-induced absence-like seizures, correlating motor behavior with changes in blood flow and blood oxygenation in the brain.

  2. Initial flight and simulator evaluation of a head up display for standard and noise abatement visual approaches

    NASA Technical Reports Server (NTRS)

    Bourquin, K.; Palmer, E. A.; Cooper, G.; Gerdes, R. M.

    1973-01-01

    A preliminary assessment was made of the adequacy of a simple head up display (HUD) for providing vertical guidance for flying noise abatement and standard visual approaches in a jet transport. The HUD featured gyro-stabilized approach angle scales which display the angle of declination to any point on the ground and a horizontal flight path bar which aids the pilot in his control of the aircraft flight path angle. Thirty-three standard and noise abatement approaches were flown in a Boeing 747 aircraft equipped with a head up display. The HUD was also simulated in a research simulator. The simulator was used to familiarize the pilots with the display and to determine the most suitable way to use the HUD for making high capture noise abatement approaches. Preliminary flight and simulator data are presented and problem areas that require further investigation are identified.

  3. Scanning pupil approach to aspheric surface slope error tolerancing in head-up display optics

    NASA Astrophysics Data System (ADS)

    Sivokon, V. P.

    2015-09-01

    We present a novel approach to tolerancing slope errors of aspheric surfaces in relay optics of typical avionics head-up displays (HUD). In these systems, a beamlet entering the pilot eye occupies only a tiny fraction of HUD entrance pupil/eyebox with a typical diameter of 125mm. Consequently the beam footprint on any HUD optical surface is a small fraction of its clear aperture. This presents challenges to HUD tolerancing which is typically based on parallax (angular difference in line of sight between left and right eyes) analysis. Aspheric surfaces manufactured by sub-aperture grinding/polishing techniques add another source of error - surface slope error. This type of error not only degrades image quality of observed HUD symbology but also leads to its "waviness" and "floating" especially noticeable when a pilot moves his head within the HUD eyebox. The suggested approach allows aspheric surface slope error tolerancing that ensures an acceptable level of symbology "waviness". A narrow beamlet is traced from a pilot eye position backwards through the HUD optics until it hits the light source. Due to the small beamlet size, slope error of the aspheric surface acts primarily as an overall tilt/wedge that deviates the beam and causes it to shift. The slope error is acceptable when this shift is not resolved by a pilot eye. The beamlet is scanned over entire eyebox and field of view and the slope error tolerance is established for several zones in the aspheric surface clear aperture. The procedure is then repeated for each aspheric surface.

  4. Identification of Prey Captures in Australian Fur Seals (Arctocephalus pusillus doriferus) Using Head-Mounted Accelerometers: Field Validation with Animal-Borne Video Cameras.

    PubMed

    Volpov, Beth L; Hoskins, Andrew J; Battaile, Brian C; Viviant, Morgane; Wheatley, Kathryn E; Marshall, Greg; Abernathy, Kyler; Arnould, John P Y

    2015-01-01

    This study investigated prey captures in free-ranging adult female Australian fur seals (Arctocephalus pusillus doriferus) using head-mounted 3-axis accelerometers and animal-borne video cameras. Acceleration data was used to identify individual attempted prey captures (APC), and video data were used to independently verify APC and prey types. Results demonstrated that head-mounted accelerometers could detect individual APC but were unable to distinguish among prey types (fish, cephalopod, stingray) or between successful captures and unsuccessful capture attempts. Mean detection rate (true positive rate) on individual animals in the testing subset ranged from 67-100%, and mean detection on the testing subset averaged across 4 animals ranged from 82-97%. Mean False positive (FP) rate ranged from 15-67% individually in the testing subset, and 26-59% averaged across 4 animals. Surge and sway had significantly greater detection rates, but also conversely greater FP rates compared to heave. Video data also indicated that some head movements recorded by the accelerometers were unrelated to APC and that a peak in acceleration variance did not always equate to an individual prey item. The results of the present study indicate that head-mounted accelerometers provide a complementary tool for investigating foraging behaviour in pinnipeds, but that detection and FP correction factors need to be applied for reliable field application. PMID:26107647

  5. Identification of Prey Captures in Australian Fur Seals (Arctocephalus pusillus doriferus) Using Head-Mounted Accelerometers: Field Validation with Animal-Borne Video Cameras

    PubMed Central

    Volpov, Beth L.; Hoskins, Andrew J.; Battaile, Brian C.; Viviant, Morgane; Wheatley, Kathryn E.; Marshall, Greg; Abernathy, Kyler; Arnould, John P. Y.

    2015-01-01

    This study investigated prey captures in free-ranging adult female Australian fur seals (Arctocephalus pusillus doriferus) using head-mounted 3-axis accelerometers and animal-borne video cameras. Acceleration data was used to identify individual attempted prey captures (APC), and video data were used to independently verify APC and prey types. Results demonstrated that head-mounted accelerometers could detect individual APC but were unable to distinguish among prey types (fish, cephalopod, stingray) or between successful captures and unsuccessful capture attempts. Mean detection rate (true positive rate) on individual animals in the testing subset ranged from 67-100%, and mean detection on the testing subset averaged across 4 animals ranged from 82-97%. Mean False positive (FP) rate ranged from 15-67% individually in the testing subset, and 26-59% averaged across 4 animals. Surge and sway had significantly greater detection rates, but also conversely greater FP rates compared to heave. Video data also indicated that some head movements recorded by the accelerometers were unrelated to APC and that a peak in acceleration variance did not always equate to an individual prey item. The results of the present study indicate that head-mounted accelerometers provide a complementary tool for investigating foraging behaviour in pinnipeds, but that detection and FP correction factors need to be applied for reliable field application. PMID:26107647

  6. Backup Alignment Devices on Shuttle: Heads-Up Display or Crew Optical Alignment Sight

    NASA Technical Reports Server (NTRS)

    Chavez, Melissa A.

    2011-01-01

    NASA s Space Shuttle was built to withstand multiple failures while still keeping the crew and vehicle safe. Although the design of the Space Shuttle had a great deal of redundancy built into each system, there were often additional ways to keep systems in the best configuration if a failure were to occur. One such method was to use select pieces of hardware in a way for which they were not primarily intended. The primary function of the Heads-Up Display (HUD) was to provide the crew with a display of flight critical information during the entry phase. The primary function of the Crew Optical Alignment Sight (COAS) was to provide the crew an optical alignment capability for rendezvous and docking phases. An alignment device was required to keep the Inertial Measurement Units (IMUs) well aligned for a safe Entry; nominally this alignment device would be the two on-board Star Trackers. However, in the event of a Star Tracker failure, the HUD or COAS could also be used as a backup alignment device, but only if the device had been calibrated beforehand. Once the HUD or COAS was calibrated and verified then it was considered an adequate backup to the Star Trackers for entry IMU alignment. There were procedures in place and the astronauts were trained on how to accurately calibrate the HUD or COAS and how to use them as an alignment device. The calibration procedure for the HUD and COAS had been performed on many Shuttle missions. Many of the first calibrations performed were for data gathering purposes to determine which device was more accurate as a backup alignment device, HUD or COAS. Once this was determined, the following missions would frequently calibrate the HUD in order to be one step closer to having the device ready in case it was needed as a backup alignment device.

  7. TRISTAR 1: Evaluation methods for testing head-up display (HUD) flight symbology

    NASA Technical Reports Server (NTRS)

    Newman, R. L.; Haworth, L. A.; Kessler, G. K.; Eksuzian, D. J.; Ercoline, W. R.; Evans, R. H.; Hughes, T. C.; Weinstein, L. F.

    1995-01-01

    The first in a series of piloted head-up display (HUD) flight symbology studies (TRISTAR) measuring pilot task performance was conducted at the NASA Ames Research Center by the Tri-Service Flight Symbology Working Group (FSWG). Sponsored by the U.S. Army Aeroflightdynamics Directorate, this study served as a focal point for the FSWG to examine HUD test methodology and flight symbology presentations. HUD climb-dive marker dynamics and climb-dive ladder presentations were examined as pilots performed air-to-air (A/A), air-to-ground (A/G), instrument landing system (ILS), and unusual attitude (UA) recover tasks. Symbolic presentations resembled pitch ladder variations used by the U.S. Air Force (USAF), U.S. Navy (USN), and Royal Air Force (RAF). The study was initiated by the FSWG to address HUD flight symbology deficiencies, standardization, issue identification, and test methodologies. It provided the mechanism by which the USAF, USN, RAF, and USA could integrate organizational ideas and reduce differences for comparisons. Specifically it examined flight symbology issues collectively identified by each organization and the use of objective and subjective text methodology and flight tasking proposed by the FSWG.

  8. The effect of a monocular helmet-mounted display on aircrew health: a 10-year prospective cohort study of Apache AH MK 1 pilots: study midpoint update

    NASA Astrophysics Data System (ADS)

    Hiatt, Keith L.; Rash, Clarence E.; Watters, Raymond W.; Adams, Mark S.

    2009-05-01

    A collaborative occupational health study has been undertaken by Headquarters Army Aviation, Middle Wallop, UK, and the U.S. Army Aeromedical Research Laboratory, Fort Rucker, Alabama, to determine if the use of the Integrated Helmet and Display Sighting System (IHADSS) monocular helmet-mounted display (HMD) in the Apache AH Mk 1 attack helicopter has any long-term (10-year) effect on visual performance. The test methodology consists primarily of a detailed questionnaire and an annual battery of vision tests selected to capture changes in visual performance of Apache aviators over their flight career (with an emphasis on binocular visual function). Pilots using binocular night vision goggles serve as controls and undergo the same methodology. Currently, at the midpoint of the study, with the exception of a possible colour discrimination effect, there are no data indicating that the long-term use of the IHADSS monocular HMD results in negative effects on vision.

  9. Enhanced/Synthetic Vision and Head-Worn Display Technologies for Terminal Maneuvering Area NextGen Operations

    NASA Technical Reports Server (NTRS)

    Arthur, Jarvis J., III; Prinzell, Lawrence J.; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

    2011-01-01

    NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field

  10. Enhanced/synthetic vision and head-worn display technologies for terminal maneuvering area NextGen operations

    NASA Astrophysics Data System (ADS)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

    2011-06-01

    NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field

  11. Head-up display system considerations for enhanced situational awareness through the integration of weather penetrating sensors

    NASA Astrophysics Data System (ADS)

    Wisely, Paul L.

    2006-05-01

    Interest has existed for a considerable period of time in migrating weather penetrating sensor technology from its origins in military applications to the civil sector, and some civil certified systems are now available on business jets. This paper discusses the issues that such a migration raises from the perspective of the requisite head up display performance requirements, and includes results of flight trials conducted in this area.

  12. Motherese by Eye and Ear: Infants Perceive Visual Prosody in Point-Line Displays of Talking Heads

    PubMed Central

    Kitamura, Christine; Guellaï, Bahia; Kim, Jeesun

    2014-01-01

    Infant-directed (ID) speech provides exaggerated auditory and visual prosodic cues. Here we investigated if infants were sensitive to the match between the auditory and visual correlates of ID speech prosody. We presented 8-month-old infants with two silent line-joined point-light displays of faces speaking different ID sentences, and a single vocal-only sentence matched to one of the displays. Infants looked longer to the matched than mismatched visual signal when full-spectrum speech was presented; and when the vocal signals contained speech low-pass filtered at 400 Hz. When the visual display was separated into rigid (head only) and non-rigid (face only) motion, the infants looked longer to the visual match in the rigid condition; and to the visual mismatch in the non-rigid condition. Overall, the results suggest 8-month-olds can extract information about the prosodic structure of speech from voice and head kinematics, and are sensitive to their match; and that they are less sensitive to the match between lip and voice information in connected speech. PMID:25353978

  13. Motherese by eye and ear: infants perceive visual prosody in point-line displays of talking heads.

    PubMed

    Kitamura, Christine; Guellaï, Bahia; Kim, Jeesun

    2014-01-01

    Infant-directed (ID) speech provides exaggerated auditory and visual prosodic cues. Here we investigated if infants were sensitive to the match between the auditory and visual correlates of ID speech prosody. We presented 8-month-old infants with two silent line-joined point-light displays of faces speaking different ID sentences, and a single vocal-only sentence matched to one of the displays. Infants looked longer to the matched than mismatched visual signal when full-spectrum speech was presented; and when the vocal signals contained speech low-pass filtered at 400 Hz. When the visual display was separated into rigid (head only) and non-rigid (face only) motion, the infants looked longer to the visual match in the rigid condition; and to the visual mismatch in the non-rigid condition. Overall, the results suggest 8-month-olds can extract information about the prosodic structure of speech from voice and head kinematics, and are sensitive to their match; and that they are less sensitive to the match between lip and voice information in connected speech. PMID:25353978

  14. An Operational evaluation of head up displays for civil transport operations. NASA/FAA phase 3 report

    NASA Technical Reports Server (NTRS)

    Lauber, J. K.; Bray, R. S.; Harrison, R. L.; Hemingway, J. C.; Scott, B. C.

    1982-01-01

    The advantages and disadvantages of head-up displays (HUDs) in commercial jet transport approach and landing operations was evaluated. Ten airline captains currently qualified in the B-727 aircraft flew a series of instrument landing system (ILS) and nonprecision approaches in a motion base simulator using both a flight director HUD concept and a flightpath HUD concept as well as conventional head-down instruments under a variety of environmental and operational conditions to assess: (1) the potential benefits of these HUDs in airline operations; (2) problems which might be associated with their use; and (3) flight crew training requirements and flight crew operating procedures suitable for use with the HUDs. Results are presented in terms of objective simulator based performance measures, subject pilot opinion and rating data, and observer data.

  15. Cross-axis adaptation improves 3D vestibulo-ocular reflex alignment during chronic stimulation via a head-mounted multichannel vestibular prosthesis.

    PubMed

    Dai, Chenkai; Fridman, Gene Y; Chiang, Bryce; Davidovics, Natan S; Melvin, Thuy-Anh; Cullen, Kathleen E; Della Santina, Charles C

    2011-05-01

    By sensing three-dimensional (3D) head rotation and electrically stimulating the three ampullary branches of a vestibular nerve to encode head angular velocity, a multichannel vestibular prosthesis (MVP) can restore vestibular sensation to individuals disabled by loss of vestibular hair cell function. However, current spread to afferent fibers innervating non-targeted canals and otolith end organs can distort the vestibular nerve activation pattern, causing misalignment between the perceived and actual axis of head rotation. We hypothesized that over time, central neural mechanisms can adapt to correct this misalignment. To test this, we rendered five chinchillas vestibular deficient via bilateral gentamicin treatment and unilaterally implanted them with a head-mounted MVP. Comparison of 3D angular vestibulo-ocular reflex (aVOR) responses during 2 Hz, 50°/s peak horizontal sinusoidal head rotations in darkness on the first, third, and seventh days of continual MVP use revealed that eye responses about the intended axis remained stable (at about 70% of the normal gain) while misalignment improved significantly by the end of 1 week of prosthetic stimulation. A comparable time course of improvement was also observed for head rotations about the other two semicircular canal axes and at every stimulus frequency examined (0.2-5 Hz). In addition, the extent of disconjugacy between the two eyes progressively improved during the same time window. These results indicate that the central nervous system rapidly adapts to multichannel prosthetic vestibular stimulation to markedly improve 3D aVOR alignment within the first week after activation. Similar adaptive improvements are likely to occur in other species, including humans.

  16. Simulation and flight test evaluation of head-up-display guidance for harrier approach transitions

    NASA Technical Reports Server (NTRS)

    Dorr, D. W.; Moralez, E., III; Merrick, V. K.

    1994-01-01

    Position and speed guidance displays for STOVL aircraft curved, decelerating approaches to hover and vertical landing have been evaluated for their effectiveness in reducing pilot workload and improving performance. The NASA V/STOL Systems Research Aircraft, a modified YAV-8B Harrier prototype, was used to evaluate the displays in flight, whereas the NASA Ames Vertical Motion Simulator was used to extend the flight test results to instrument meteorological conditions (IMC) and to examine performance in various conditions of wind and turbulence. The simulation data showed close correlation with the flight test data, and both demonstrated the feasibility of the displays. With the exception of the hover task in zero visibility, which was level-3, averaged Copper-Harper handling qualities ratings given during simulation were level-2 for both the approach task and the hover task in all conditions. During flight tests in calm and clear conditions, the displays also gave rise to level-2 handling qualities ratings. Pilot opinion showed that the guidance displays would be useful in visual flight, especially at night, as well as in IMC.

  17. Simulation and flight test evaluation of head-up-display guidance for Harrier approach transitions

    NASA Technical Reports Server (NTRS)

    Dorr, D. W.; Moralez, E., III; Merrick, V. K.

    1992-01-01

    Position and speed guidance displays for STOVL aircraft curved, decelerating approaches to hover and vertical landing have been evaluated for their effectiveness in reducing pilot workload and improving performance. The NASA V/STOL Systems Research Aircraft, a modified YAV-8B Harrier prototype, was used to evaluate the displays in flight, while the NASA Ames Vertical Motion Simulator was used to extend the flight test results to instrument meteorological conditions (IMC) and to examine performance in various conditions of wind and turbulence. The simulation data showed close correlation with the flight test data, and both demonstrated the feasibility of the displays. With the exception of the hover task in zero visibility, which was Level-3, averaged Cooper-Harper handling qualities ratings given during simulation were Level-2 for both the approach task and the hover task in all conditions. During flight tests in calm and clear conditions, the displays also gave rise to Level-2 handling qualities ratings. Pilot opinion showed that the guidance displays would be useful in visual flight, especially at night, as well as in IMC.

  18. A preliminary study of head-up display assessment techniques. 2: HUD symbology and panel information search time

    NASA Technical Reports Server (NTRS)

    Guercio, J. G.; Haines, R. F.

    1978-01-01

    Twelve commercial pilots were shown 50 high-fidelity slides of a standard aircraft instrument panel with the airspeed, altitude, ADI, VSI, and RMI needles in various realistic orientations. Fifty slides showing an integrated head-up display (HUD) symbology containing an equivalent number of flight parameters as above (with flight path replacing VSI) were also shown. Each subject was told what flight parameter to search for just before each slide was exposed and was given as long as needed (12 sec maximum) to respond by verbalizing the parameter's displayed value. The results for the 100-percent correct data indicated that: there was no significant difference in mean reaction time (averaged across all five flight parameters) between the instrument panel and HUD slides; and a statistically significant difference in mean reaction time was found in responding to different flight parameters.

  19. Microscope-integrated intraoperative OCT with electrically tunable focus and heads-up display for imaging of ophthalmic surgical maneuvers

    PubMed Central

    Tao, Yuankai K.; Srivastava, Sunil K.; Ehlers, Justis P.

    2014-01-01

    We present novel optical and mechanical designs for a microscope-integrated intraoperative optical coherence tomography (iOCT) system with enhanced function and ergonomics for visualization of ophthalmic surgical maneuvers. Integration of an electrically tunable lens allows rapid focal plane adjustment and iOCT imaging of both anterior and posterior segment tissue microstructures while maintaining parfocality with the ophthalmic surgical microscope. We demonstrate novel visualization of instrument positions relative to tissue layers of interest as colormap overlays onto en face OCT data, which may provide integrative display of volumetric information during surgical maneuvers. Finally, we implement a heads-up display system to provide real-time feedback as proof-of-principle for iOCT-guided ophthalmic surgery. PMID:24940546

  20. Optoelectronic Mounting Structure

    DOEpatents

    Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R. F.; Bryan, Robert P.; Carson, Richard F.; Chu, Dahwey; Duckett, III, Edwin B.; McCormick, Frederick B.; Peterson, David W.; Peterson, Gary D.; Reber, Cathleen A.; Reysen, Bill H.

    2004-10-05

    An optoelectronic mounting structure is provided that may be used in conjunction with an optical transmitter, receiver or transceiver module. The mounting structure may be a flexible printed circuit board. Thermal vias or heat pipes in the head region may transmit heat from the mounting structure to the heat spreader. The heat spreader may provide mechanical rigidity or stiffness to the heat region. In another embodiment, an electrical contact and ground plane may pass along a surface of the head region so as to provide an electrical contact path to the optoelectronic devices and limit electromagnetic interference. In yet another embodiment, a window may be formed in the head region of the mounting structure so as to provide access to the heat spreader. Optoelectronic devices may be adapted to the heat spreader in such a manner that the devices are accessible through the window in the mounting structure.

  1. Globular Head-Displayed Conserved Influenza H1 Hemagglutinin Stalk Epitopes Confer Protection against Heterologous H1N1 Virus

    PubMed Central

    Klausberger, Miriam; Tscheliessnig, Rupert; Neff, Silke; Nachbagauer, Raffael; Wohlbold, Teddy John; Wilde, Monika; Palmberger, Dieter; Krammer, Florian; Jungbauer, Alois; Grabherr, Reingard

    2016-01-01

    Significant genetic variability in the head region of the influenza A hemagglutinin, the main target of current vaccines, makes it challenging to develop a long-lived seasonal influenza prophylaxis. Vaccines based on the conserved hemagglutinin stalk domain might provide broader cross-reactive immunity. However, this region of the hemagglutinin is immunosubdominant to the head region. Peptide-based vaccines have gained much interest as they allow the immune system to focus on relevant but less immunogenic epitopes. We developed a novel influenza A hemagglutinin-based display platform for H1 hemagglutinin stalk peptides that we identified in an epitope mapping assay using human immune sera and synthetic HA peptides. Flow cytometry and competition assays suggest that the identified stalk sequences do not recapitulate the epitopes of already described broadly neutralizing stalk antibodies. Vaccine constructs displaying 25-mer stalk sequences provided up to 75% protection from lethal heterologous virus challenge in BALB/c mice and induced antibody responses against the H1 hemagglutinin. The developed platform based on a vaccine antigen has the potential to be either used as stand-alone or as prime-vaccine in combination with conventional seasonal or pandemic vaccines for the amplification of stalk-based cross-reactive immunity in humans or as platform to evaluate the relevance of viral peptides/epitopes for protection against influenza virus infection. PMID:27088239

  2. Globular Head-Displayed Conserved Influenza H1 Hemagglutinin Stalk Epitopes Confer Protection against Heterologous H1N1 Virus.

    PubMed

    Klausberger, Miriam; Tscheliessnig, Rupert; Neff, Silke; Nachbagauer, Raffael; Wohlbold, Teddy John; Wilde, Monika; Palmberger, Dieter; Krammer, Florian; Jungbauer, Alois; Grabherr, Reingard

    2016-01-01

    Significant genetic variability in the head region of the influenza A hemagglutinin, the main target of current vaccines, makes it challenging to develop a long-lived seasonal influenza prophylaxis. Vaccines based on the conserved hemagglutinin stalk domain might provide broader cross-reactive immunity. However, this region of the hemagglutinin is immunosubdominant to the head region. Peptide-based vaccines have gained much interest as they allow the immune system to focus on relevant but less immunogenic epitopes. We developed a novel influenza A hemagglutinin-based display platform for H1 hemagglutinin stalk peptides that we identified in an epitope mapping assay using human immune sera and synthetic HA peptides. Flow cytometry and competition assays suggest that the identified stalk sequences do not recapitulate the epitopes of already described broadly neutralizing stalk antibodies. Vaccine constructs displaying 25-mer stalk sequences provided up to 75% protection from lethal heterologous virus challenge in BALB/c mice and induced antibody responses against the H1 hemagglutinin. The developed platform based on a vaccine antigen has the potential to be either used as stand-alone or as prime-vaccine in combination with conventional seasonal or pandemic vaccines for the amplification of stalk-based cross-reactive immunity in humans or as platform to evaluate the relevance of viral peptides/epitopes for protection against influenza virus infection. PMID:27088239

  3. Advanced helmet mounted display (AHMD)

    NASA Astrophysics Data System (ADS)

    Sisodia, Ashok; Bayer, Michael; Townley-Smith, Paul; Nash, Brian; Little, Jay; Cassarly, William; Gupta, Anurag

    2007-04-01

    Due to significantly increased U.S. military involvement in deterrent, observer, security, peacekeeping and combat roles around the world, the military expects significant future growth in the demand for deployable virtual reality trainers with networked simulation capability of the battle space visualization process. The use of HMD technology in simulated virtual environments has been initiated by the demand for more effective training tools. The AHMD overlays computer-generated data (symbology, synthetic imagery, enhanced imagery) augmented with actual and simulated visible environment. The AHMD can be used to support deployable reconfigurable training solutions as well as traditional simulation requirements, UAV augmented reality, air traffic control and Command, Control, Communications, Computers, Intelligence, Surveillance, and Reconnaissance (C4ISR) applications. This paper will describe the design improvements implemented for production of the AHMD System.

  4. Stereoscopic display employing head-position tracking using large format lenses

    NASA Astrophysics Data System (ADS)

    Hattori, Tomohiko

    1993-09-01

    Two stereoscopic systems are described which permits the observation of a high resolution image by several persons simultaneously and suited to mass production. One is a time- parallel method and another is a time-interlaced method. In the time-parallel stereoscopic display system, by mechanically driving several video projectors according to the observers' eye position, the images projected on a large format convex lenses are varied, the left image rays continuously entering the observers' left eyes and vice versa. In the time-interlaced stereoscopic display system, the image output screen is formed by a transparent type color liquid crystal plate with a large format lens. The lens is arranged so that an image of viewers is projected to the plane of a black-and-white CRT which is positioned behind as a back light of the system. To view the stereo image on the color liquid crystal plate, the alternating left- and right-eye perspectives must be synchronized with an infrared lightening system and the imaging of the viewers on the CRT that the back light distributes the light to the left eyes when the left-eye view is displayed on the color liquid crystal plate and vice versa.

  5. Transparent 3D display for augmented reality

    NASA Astrophysics Data System (ADS)

    Lee, Byoungho; Hong, Jisoo

    2012-11-01

    Two types of transparent three-dimensional display systems applicable for the augmented reality are demonstrated. One of them is a head-mounted-display-type implementation which utilizes the principle of the system adopting the concave floating lens to the virtual mode integral imaging. Such configuration has an advantage in that the threedimensional image can be displayed at sufficiently far distance resolving the accommodation conflict with the real world scene. Incorporating the convex half mirror, which shows a partial transparency, instead of the concave floating lens, makes it possible to implement the transparent three-dimensional display system. The other type is the projection-type implementation, which is more appropriate for the general use than the head-mounted-display-type implementation. Its imaging principle is based on the well-known reflection-type integral imaging. We realize the feature of transparent display by imposing the partial transparency to the array of concave mirror which is used for the screen of reflection-type integral imaging. Two types of configurations, relying on incoherent and coherent light sources, are both possible. For the incoherent configuration, we introduce the concave half mirror array, whereas the coherent one adopts the holographic optical element which replicates the functionality of the lenslet array. Though the projection-type implementation is beneficial than the head-mounted-display in principle, the present status of the technical advance of the spatial light modulator still does not provide the satisfactory visual quality of the displayed three-dimensional image. Hence we expect that the head-mounted-display-type and projection-type implementations will come up in the market in sequence.

  6. Color speckle in laser displays

    NASA Astrophysics Data System (ADS)

    Kuroda, Kazuo

    2015-07-01

    At the beginning of this century, lighting technology has been shifted from discharge lamps, fluorescent lamps and electric bulbs to solid-state lighting. Current solid-state lighting is based on the light emitting diodes (LED) technology, but the laser lighting technology is developing rapidly, such as, laser cinema projectors, laser TVs, laser head-up displays, laser head mounted displays, and laser headlamps for motor vehicles. One of the main issues of laser displays is the reduction of speckle noise1). For the monochromatic laser light, speckle is random interference pattern on the image plane (retina for human observer). For laser displays, RGB (red-green-blue) lasers form speckle patterns independently, which results in random distribution of chromaticity, called color speckle2).

  7. Head mounted DLP for visual stimulation in freely moving rats: a novel tool for visual neuroscience research

    NASA Astrophysics Data System (ADS)

    Mandel, Yossi; Arens-Arad, Tamar; Farah, Nairouz; Zlotnik, Alex; Zalevsky, Zeev

    2015-03-01

    Novel technologies are constantly under development for vision restoration in blind patients. In some of these techniques, such as photodiode implants or optogenetics based treatment, a glasses mounted optical projection system projects the visual scene onto the retina. The desired projection system is characterized by a relatively high power density, a localized retinal stimulation area and compatibility for wavelengths that are specific for the technology at hand. The challenges of obtaining such a projection system are not only limited by developing the tools and the apparatus for testing the visual performance of artificial retina, but also devising the technique and the methodology for training and testing the behaving animals using this tool. Current research techniques used for evaluation of visual function in behaving animals utilize computer screens for retinal stimulation, and therefore do not fulfill the requirements of the evaluation of retinal implant performance or optogenetics based treatment (inefficient power and no wavelength flexibility). In the following work we will present and evaluate a novel projection system that is suited for behavioral animal studies and meet the requirements for artificial retinal stimulation. The proposed system is based on a miniature Digital Mirror Device (DMD) for pattern projection and a telescope for relaying the pattern directly onto the animal eye. This system facilitates the projection of patterns with high spatial resolution at high light intensities with the desired wavelength and may prove to be a vital tool in natural and artificial vision performance research in behaving animals.

  8. Broad-band green phosphor screens as a light source for head up displays in moving platforms

    NASA Astrophysics Data System (ADS)

    Silver, Jack; Withnall, Robert; Rose, John; Wilstead, Nicola; Fern, George; Bishton, Stephen; Klein, David; Rhodes, Bob; Barclay, Charles; Whitmarsh, John

    2005-06-01

    A broad-band green light source for a head-up display is presented. To our knowledge, this is the first report of a green phosphor screen being excited by a blue LED as a backlight for monochrome HUDs. The phosphor screen not only generates the green light but it acts as a diffuser to give a homogeneous illumination. A microlens array focuses the emissions from LED sources on to the diffusing screen eliminating halo effects from the individual LEDs. The purpose of using a green phosphor is to exploit the fact that the eye is sensitive to more shades of green than any other colour. In uses where there are elements of danger such as automobiles (in busy areas), vehicles on construction sites and military vehicles in war zones, green displays have obvious attractions. This paper presents a discussion of the green phosphors that can be used in green screen fabrication, the deposition of the phosphor powders on the screens, the influence of the thickness of the phosphor powder on the screen brightness. In addition, the factors that influence the CIE coordinates of the light emitted from the screen are considered. The importance of choosing the optimum LED emission wavelength along with the general construction of the HUD is discussed. The merits of using a green screen are compared to those when using full colour displays based on white phosphor screens in which yellow emitting phosphors are excited by blue LEDs. Heat management in these HUD devices is achieved by pulsing the LEDs and rastering rows within the LED array.

  9. Design and testing of an unlimited field-of-regard synthetic vision head-worn display for commercial aircraft surface operations

    NASA Astrophysics Data System (ADS)

    Arthur, J. J., III; Prinzel, Lawrence, III; Shelton, Kevin; Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Norman, Robert M.

    2007-04-01

    Experiments and flight tests have shown that a Head-Up Display (HUD) and a head-down, electronic moving map (EMM) can be enhanced with Synthetic Vision for airport surface operations. While great success in ground operations was demonstrated with a HUD, the research noted that two major HUD limitations during ground operations were their monochrome form and limited, fixed field of regard. A potential solution to these limitations found with HUDs may be emerging Head Worn Displays (HWDs). HWDs are small, lightweight full color display devices that may be worn without significant encumbrance to the user. By coupling the HWD with a head tracker, unlimited field-of-regard may be realized for commercial aviation applications. In the proposed paper, the results of two ground simulation experiments conducted at NASA Langley are summarized. The experiments evaluated the efficacy of head-worn display applications of Synthetic Vision and Enhanced Vision technology to enhance transport aircraft surface operations. The two studies tested a combined six display concepts: (1) paper charts with existing cockpit displays, (2) baseline consisting of existing cockpit displays including a Class III electronic flight bag display of the airport surface; (3) an advanced baseline that also included displayed traffic and routing information, (4) a modified version of a HUD and EMM display demonstrated in previous research; (5) an unlimited field-of-regard, full color, head-tracked HWD with a conformal 3-D synthetic vision surface view; and (6) a fully integrated HWD concept. The fully integrated HWD concept is a head-tracked, color, unlimited field-of-regard concept that provides a 3-D conformal synthetic view of the airport surface integrated with advanced taxi route clearance, taxi precision guidance, and data-link capability. The results of the experiments showed that the fully integrated HWD provided greater path performance compared to using paper charts alone. Further, when

  10. Design and Testing of an Unlimited Field-of-regard Synthetic Vision Head-worn Display for Commercial Aircraft Surface Operations

    NASA Technical Reports Server (NTRS)

    Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Shelton, Kevin J.; Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Norman, Robert M.

    2007-01-01

    Experiments and flight tests have shown that a Head-Up Display (HUD) and a head-down, electronic moving map (EMM) can be enhanced with Synthetic Vision for airport surface operations. While great success in ground operations was demonstrated with a HUD, the research noted that two major HUD limitations during ground operations were their monochrome form and limited, fixed field of regard. A potential solution to these limitations found with HUDs may be emerging Head Worn Displays (HWDs). HWDs are small, lightweight full color display devices that may be worn without significant encumbrance to the user. By coupling the HWD with a head tracker, unlimited field-of-regard may be realized for commercial aviation applications. In the proposed paper, the results of two ground simulation experiments conducted at NASA Langley are summarized. The experiments evaluated the efficacy of head-worn display applications of Synthetic Vision and Enhanced Vision technology to enhance transport aircraft surface operations. The two studies tested a combined six display concepts: (1) paper charts with existing cockpit displays, (2) baseline consisting of existing cockpit displays including a Class III electronic flight bag display of the airport surface; (3) an advanced baseline that also included displayed traffic and routing information, (4) a modified version of a HUD and EMM display demonstrated in previous research; (5) an unlimited field-of-regard, full color, head-tracked HWD with a conformal 3-D synthetic vision surface view; and (6) a fully integrated HWD concept. The fully integrated HWD concept is a head-tracked, color, unlimited field-of-regard concept that provides a 3-D conformal synthetic view of the airport surface integrated with advanced taxi route clearance, taxi precision guidance, and data-link capability. The results of the experiments showed that the fully integrated HWD provided greater path performance compared to using paper charts alone. Further, when

  11. Evaluation of Microscopic Disease in Oral Tongue Cancer Using Whole-Mount Histopathologic Techniques: Implications for the Management of Head-and-Neck Cancers

    SciTech Connect

    Campbell, Sorcha; Poon, Ian; Markel, Dan; Vena, Dan; Higgins, Kevin; Enepekides, Dan; Rapheal, Simon; Wong, John; Allo, Ghassan; Morgen, Eric; Khaoum, Nader; Smith, Ben; Balogh, Judith; MacKenzie, Robert; Davidson, Jean; Wang, Dan; Yaffe, Martin

    2012-02-01

    Purpose: To map the distribution of microscopic disease (MD) in head-and-neck cancer by analyzing digital images of whole-mounted serial sections of tongue cancer specimens. Methods and Materials: Ten T1-3 oral tongue cancer specimens were evaluated. The specimens were sliced into 3-mm blocks from which one or more 4-{mu}m slides were taken and digitized to create whole-mounted serial sections. Gross tumor and microscopic disease were digitally contoured on each slide. Lines perpendicular to the gross tumor volume (GTV) edge were created at 0.05-mm intervals and the distance between GTV and MD measured. Results: Of 88 slides assessed, 44 (50%) had evidence of MD. Of the 63,809 perpendicular lines drawn along the GTV edges, 2320 (3.6%) encountered microscopic disease along their path. The majority of MD abutted the GTV, and only 26.7% was noncontiguous with the GTV edge. The maximum distance from the border was 7.8 mm. Ninety-nine percent of all MD was within 4.75 mm and 95% was within 3.95 mm of the GTV. Conclusion: In this study we were able to assess the distribution of MD more accurately than has been possible with routine pathologic techniques. The results indicate that when the GTV is correctly identified, there is very little MD to be found outside this volume. This has implications for the volume of tissue resected at surgery and the volume included in the clinical target volume in conformal radiotherapy planning.

  12. Head orientation prediction: delta quaternions versus quaternions.

    PubMed

    Himberg, Henry; Motai, Yuichi

    2009-12-01

    Display lag in simulation environments with helmet-mounted displays causes a loss of immersion that degrades the value of virtual/augmented reality training simulators. Simulators use predictive tracking to compensate for display lag, preparing display updates based on the anticipated head motion. This paper proposes a new method for predicting head orientation using a delta quaternion (DQ)-based extended Kalman filter (EKF) and compares the performance to a quaternion EKF. The proposed framework operates on the change in quaternion between consecutive data frames (the DQ), which avoids the heavy computational burden of the quaternion motion equation. Head velocity is estimated from the DQ by an EKF and then used to predict future head orientation. We have tested the new framework with captured head motion data and compared it with the computationally expensive quaternion filter. Experimental results indicate that the proposed DQ method provides the accuracy of the quaternion method without the heavy computational burden.

  13. Measuring dwell time percentage from head-mounted eye-tracking data--comparison of a frame-by-frame and a fixation-by-fixation analysis.

    PubMed

    Vansteenkiste, Pieter; Cardon, Greet; Philippaerts, Renaat; Lenoir, Matthieu

    2015-01-01

    Although analysing software for eye-tracking data has significantly improved in the past decades, the analysis of gaze behaviour recorded with head-mounted devices is still challenging and time-consuming. Therefore, new methods have to be tested to reduce the analysis workload while maintaining accuracy and reliability. In this article, dwell time percentages to six areas of interest (AOIs), of six participants cycling on four different roads, were analysed both frame-by-frame and in a 'fixation-by-fixation' manner. The fixation-based method is similar to the classic frame-by-frame method but instead of assigning frames, fixations are assigned to one of the AOIs. Although some considerable differences were found between the two methods, a Pearson correlation of 0.930 points out a good validity of the fixation-by-fixation method. For the analysis of gaze behaviour over an extended period of time, the fixation-based approach is a valuable and time-saving alternative for the classic frame-by-frame analysis. PMID:25529829

  14. Plasma Screen Floating Mount

    DOEpatents

    Eakle, Robert F.; Pak, Donald J.

    2004-10-26

    A mounting system for a flat display screen, particularly a plasma display screen, suspends the screen separately in each of the x-, y- and z-directions. A series of frames located by linear bearings and isolated by springs and dampers allows separate controlled movement in each axis. The system enables the use of relatively larger display screens in vehicles in which plasma screen are subject to damage from vibration.

  15. New ultraportable display technology and applications

    NASA Astrophysics Data System (ADS)

    Alvelda, Phillip; Lewis, Nancy D.

    1998-08-01

    MicroDisplay devices are based on a combination of technologies rooted in the extreme integration capability of conventionally fabricated CMOS active-matrix liquid crystal display substrates. Customized diffraction grating and optical distortion correction technology for lens-system compensation allow the elimination of many lenses and systems-level components. The MicroDisplay Corporation's miniature integrated information display technology is rapidly leading to many new defense and commercial applications. There are no moving parts in MicroDisplay substrates, and the fabrication of the color generating gratings, already part of the CMOS circuit fabrication process, is effectively cost and manufacturing process-free. The entire suite of the MicroDisplay Corporation's technologies was devised to create a line of application- specific integrated circuit single-chip display systems with integrated computing, memory, and communication circuitry. Next-generation portable communication, computer, and consumer electronic devices such as truly portable monitor and TV projectors, eyeglass and head mounted displays, pagers and Personal Communication Services hand-sets, and wristwatch-mounted video phones are among the may target commercial markets for MicroDisplay technology. Defense applications range from Maintenance and Repair support, to night-vision systems, to portable projectors for mobile command and control centers.

  16. A Lightweight Innovative Helmet Airborne Display And Sight (HADAS)

    NASA Astrophysics Data System (ADS)

    Naor, Daniel; Arnon, Oded; Avnur, Arie

    1987-09-01

    The Helmet Airborne Display and Sight (HADAS) system under development, has succeeded in surmounting many of the problems experienced by current, as well as past helmet mounted display and sight designs for operation in fighter aircraft. The goal has been achieved by combination of holographic optical elements and fiber optics for the display function, as well as real-time image processing of the helmet location for the sight function. The integrated system can provide "all aspect head-up display" performance in the cockpit.

  17. Brightness increase in an LCD stereo display

    NASA Astrophysics Data System (ADS)

    Rallison, Richard D.; Schicker, Scott R.

    1994-05-01

    A practical head mounted display (HMD) has to be light enough and bright enough to wear and view without undue strain on the users head or eyes. A 10 pound CRT based helmet is not always out of the question but binocular or stereo HMDs using LCDs rather than CRTs need only weigh in at around one pound complete with electronics and are far more comfortable to wear. The space bandwidth product or pixel count of LCDs is now approaching that of CRT type displays but LCDs could use a big boost in brightness, especially for see thru designs. The see thru or head up style has many user advantages and this paper addresses ways to more efficiently transmit photons from the source to the eye in one such design. All of the components that are used to improve performance may be made holographically or in an alternate fashion. The most practical method of construction is probably a toss up for some components.

  18. A review of some head-up display formats. [tests on sensing equipment for flights following partly visible terrain close to the ground

    NASA Technical Reports Server (NTRS)

    Naish, J. M.

    1979-01-01

    Two alternate head-up display devices (HUD) were compared for properties relevant to the accurate performance of concurrent tasks in real flight conditions and in various flight modes. The comparisons were made to find the disorientation resistance of the HUDs along with the tracking accuracy, interference resistance, fixation resistance, and error resistance. The use of displacement and flight path information for vertical control is discussed in terms of flight stability. Several combinations of symbols and driving signals are described, including a compensated control law, which were used in simulated flight to deal with wind shear.

  19. The role of cognitive switching in head-up displays. [to determine pilot ability to accurately extract information from either of two sources

    NASA Technical Reports Server (NTRS)

    Fischer, E.

    1979-01-01

    The pilot's ability to accurately extract information from either one or both of two superimposed sources of information was determined. Static, aerial, color 35 mm slides of external runway environments and slides of corresponding static head-up display (HUD) symbology were used as the sources. A three channel tachistoscope was utilized to show either the HUD alone, the scene alone, or the two slides superimposed. Cognitive performance of the pilots was assessed by determining the percentage of correct answers given to two HUD related questions, two scene related questions, or one HUD and one scene related question.

  20. Mirror mount

    DOEpatents

    Humpal, Harold H.

    1987-01-01

    A mirror mount (10) is provided that allows free pitch, yaw and roll motion of the mirror (28) while keeping the location of a point (56) on the surface of the mirror (28) fixed in the rest frame of reference of the mount (10). Yaw movement is provided by two yaw cylinders (30,32) that are bearing (52) mounted to provide rotation. Pitch and roll motion is provided by a spherically annular shell (42) that is air bearing (72,74) mounted to move between a clamp (60) and an upper pedestal bearing (44). The centers of curvature of the spherical surfaces of the shell (42) lie upon the point (56). Pitch motion and roll motion are separately and independently imparted to mirror (28) by a pair of pitch paddles (34) and a pair of roll paddles (36) that are independently and separately moved by control rods (76,80) driven by motors (78,82).

  1. Mirror mount

    DOEpatents

    Humpal, H.H.

    1986-03-21

    A mirror mount is provided that allows free pitch, yaw and roll motion of the mirror while keeping the location of a point on the surface of the mirror fixed in the rest frame of reference of the mount. Yaw movement is provided by two yaw cylinders that are bearing mounted to provide rotation. Pitch and roll motion is provided by a spherically annular shell that is air bearing mounted to move between a clamp and an upper pedestal bearing. The centers of curvature of the spherical surfaces of the shell lie upon the point. Pitch motion and roll motion are separately and independently imparted to mirror by a pair of pitch paddles and a pair of roll paddles that are independently and separately moved by control rods driven by motors.

  2. Mirror mount

    DOEpatents

    Humpal, H.H.

    1987-11-10

    A mirror mount is provided that allows free pitch, yaw and roll motion of the mirror while keeping the location of a point on the surface of the mirror fixed in the rest frame of reference of the mount. Yaw movement is provided by two yaw cylinders that are bearing mounted to provide rotation. Pitch and roll motion is provided by a spherically annular shell that is air bearing mounted to move between a clamp and an upper pedestal bearing. The centers of curvature of the spherical surfaces of the shell lie upon the point. Pitch motion and roll motion are separately and independently imparted to mirror by a pair of pitch paddles and a pair of roll paddles that are independently and separately moved by control rods driven by motors. 5 figs.

  3. Mirror mount

    DOEpatents

    Kuklo, Thomas C.; Bender, Donald A.

    1994-01-01

    A unique lens or mirror mount having adjustable constraints at two key locations to allow for "X" and "Y" tilts of the mirror only. The device uses two pair of flexures of a type such that the pivots of the mirror gimble are rigidly fixed in all planes allowing the device to have zero stacking tolerance and zero wear over time.

  4. Carp head kidney leukocytes display different patterns of oxygen radical production after stimulation with PAMPs and DAMPs.

    PubMed

    Vera-Jimenez, N I; Nielsen, M E

    2013-10-01

    Wound healing and tissue regeneration are essential mechanisms to ensure the survival and health of any organism. Despite this, only a few studies have been devoted to study tissue regeneration during wound healing in fish. Reactive oxygen species (ROS), in particular hydrogen peroxide, play an important dual role both for promoting tissue repair, but also for eradication of pathogens. This study aims at dissecting the contribution of PAMPs (using β-glucan) and DAMPs in the respiratory burst response of carp head kidney-derived leukocytes, and address their contribution to wound healing processes. Consistent with a pathogen eradication strategy, ROS responses to PAMP stimulation (β-glucan) was fast, vigorous and highly dominated by production of superoxide anion. In contrast, stimulation with DAMPs led to a slow, subtle but long-lasting production of oxygen radicals dominated by hydrogen peroxide. Using an in vitro model of scratch-wounded CCB fibroblast cell cultures and a novel PhotoID proliferation assay, stimulation with low and continuous levels of hydrogen peroxide (5 μM) led to a slight increase in the percentage of wound recovery and thus promoted wound closure. In contrast, high doses of hydrogen peroxide (300 μM) impaired fibroblast scratch-wound recovery and caused cell death. These results elucidate the capacity of hydrogen peroxide to influence the fate of tissue regeneration through the establishment of environments suitable for promoting either tissue regeneration or oxidative stress and thereby potential tissue damage. Direct in vitro stimulation with β-glucans did not impact fibroblast scratch-wound recovery, which further suggests that interaction with tissue-resident leukocytes or other components of the fish immune system are required to induce fibroblast proliferation and thus for the accelerated wound healing promoted by β-glucan stimulation. PMID:23517739

  5. Mirror mount

    DOEpatents

    Kuklo, T.C.; Bender, D.A.

    1994-10-04

    A unique lens or mirror mount having adjustable constraints at two key locations to allow for ''X'' and ''Y'' tilts of the mirror only is disclosed. The device uses two pair of flexures of a type such that the pivots of the mirror gimble are rigidly fixed in all planes allowing the device to have zero stacking tolerance and zero wear over time. 4 figs.

  6. Comanche Helmet-Mounted Display Symbology Evaluation

    NASA Technical Reports Server (NTRS)

    Dowell, Susan R.; Turpin, Terry; Shively, R. Jay; Szoboszlay, Zoltan

    2004-01-01

    This study assessed pilot-vehicle performance and workload associated with flying the Comanche Contact Analog, world-referenced primary flight symbology when compared with a conventional, screen-fixed, Compressed symbology. Previous investigation had revealed benefits when utilizing Compressed symbology in constrained flight maneuvers. The current evaluation further evaluated the effects of symbology by testing pilots in a high-fidelity simulator, executing more operational tasks. Flight performance and subjective ratings from six experimental test pilots were collected. Results replicated previous findings, and no performance differences were found in operational tasks. Pilot comments revealed significant preference for Compressed symbology, while some aspects of Contact Analog symbology raised objections. Performance, preference, and safety of flight issues perceived by test pilots merit a review of Contact Analog symbology design.

  7. Real-time simulation of combined short-wave and long-wave infrared vision on a head-up display

    NASA Astrophysics Data System (ADS)

    Peinecke, Niklas; Schmerwitz, Sven

    2014-05-01

    Landing under adverse weather conditions can be challenging, even if the airfields are well known to the pilots. This is true for civil as well as military aviation. Within the scope of this paper we concentrate especially on fog conditions. The work has been conducted within the project ALICIA. ALICIA is a research and development project co-funded by European Commission under the Seventh Framework Programme. ALICIA aims at developing new and scalable cockpit applications which can extend operations of aircraft in degraded conditions: All Conditions Operations. One of the systems developed is a head-up display that can display a generated symbology together with a raster-mode infrared image. We will detail how we implemented a real-time enabled simulation of a combined short-wave and long-wave infrared image for landing. A major challenge was to integrate several already existing simulation solutions, e.g., for visual simulation and sensors with the required data-bases. For the simulations DLRs in-house sensor simulation framework F3S was used, together with a commercially available airport model that had to be heavily modified in order to provide realistic infrared data. Special effort was invested for a realistic impression of runway lighting under foggy conditions. We will present results and sketch further improvements for future simulations.

  8. Design and fabrication of semi-transparent screen based on micro-patterns for direct-view type head-up display in automobiles

    NASA Astrophysics Data System (ADS)

    Lee, Jae-Yong; Kim, Hyo-Jun; Kim, Young-Joo

    2016-02-01

    A semi-transparent screen with hemisphere micro-patterns was proposed and designed to enhance the brightness uniformity of the display image toward the driver for a direct-view type head-up display. The hemisphere micro-patterns were designed to consider the inclined angle of the windshield for efficient reflection and scattering toward to the driver. The density and radius of the hemisphere micro-patterns were adjusted as a function of position on the screen based on the geometrical calculation and analyzed by the commercial optical simulation tool based on a ray-tracing method. The designed hemisphere micro-patterns was fabricated by the thermal reflow method and evaluated to confirm the uniform illumination. From the results, the semi-transparent screen with variable micro-patterns shows the 91.9 % of brightness uniformity with the enhanced luminance compare to a screen without micro-patterns. A luminance of fabricated screen also shows good agreement with the simulation result to reflect the clear and bright driving information to the driver.

  9. Military display market segment: wearable and portable

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    2003-09-01

    The military display market (MDM) is analyzed in terms of one of its segments, wearable and portable displays. Wearable and portable displays are those embedded in gear worn or carried by warfighters. Categories include hand-mobile (direct-view and monocular/binocular), palm-held, head/helmet-mounted, body-strapped, knee-attached, lap-born, neck-lanyard, and pocket/backpack-stowed. Some 62 fielded and developmental display sizes are identified in this wearable/portable MDM segment. Parameters requiring special consideration, such as weight, luminance ranges, light emission, viewing angles, and chromaticity coordinates, are summarized and compared. Ruggedized commercial versus commercial off-the-shelf designs are contrasted; and a number of custom displays are also found in this MDM category. Display sizes having aggregate quantities of 5,000 units or greater or having 2 or more program applications are identified. Wearable and portable displays are also analyzed by technology (LCD, LED, CRT, OLED and plasma). The technical specifications and program history of several high-profile military programs are discussed to provide a systems context for some representative displays and their function. As of August 2002 our defense-wide military display market study has documented 438,882 total display units distributed across 1,163 display sizes and 438 weapon systems. Wearable and portable displays account for 202,593 displays (46% of total DoD) yet comprise just 62 sizes (5% of total DoD) in 120 weapons systems (27% of total DoD). Some 66% of these wearable and portable applications involve low information content displays comprising just a few characters in one color; however, there is an accelerating trend towards higher information content units capable of showing changeable graphics, color and video.

  10. Advanced rotorcraft helmet display sighting system optics

    NASA Astrophysics Data System (ADS)

    Raynal, Francois; Chen, Muh-Fa

    2002-08-01

    Kaiser Electronics' Advanced Rotorcraft Helmet Display Sighting System is a Biocular Helmet Mounted Display (HMD) for Rotary Wing Aviators. Advanced Rotorcraft HMDs requires low head supported weight, low center of mass offsets, low peripheral obstructions of the visual field, large exit pupils, large eye relief, wide field of view (FOV), high resolution, low luning, sun light readability with high contrast and low prismatic deviations. Compliance with these safety, user acceptance and optical performance requirements is challenging. The optical design presented in this paper provides an excellent balance of these different and conflicting requirements. The Advanced Rotorcraft HMD optical design is a pupil forming off axis catadioptric system that incorporates a transmissive SXGA Active Matrix liquid Crystal Display (AMLCD), an LED array backlight and a diopter adjustment mechanism.

  11. Integrated primary flight display: the sky arc

    NASA Astrophysics Data System (ADS)

    Voulgaris, Theodore J.; Metalis, Sam A.; Mobley, R. S.

    1995-05-01

    Flight instrument interpretability has been a key piloting issue because it is directly related to operator performance and inversely related to operator error. To improve interpretability we have developed the Sky Arc, a new symbology initially developed for attitude control, particularly for a helmet-mounted display. It consists of an integrated set of graphic symbols which vary in a continuous, analog fashion with changing flight parameters. The Sky Arc currently integrates, pitch, roll, heading, air speed, and terrain avoidance. The display can be integrated into a head down display, a head up display, or a helmet mounted display. In this preliminary study the usability of the Sky Arc as an attitude indicator was compared to a conventional head-up display pitch ladder symbology. The test involved six test subject pilots and a medium-fidelity simulator. The pilots were asked to fully recover from a series of unusual attitude conditions that were presented on the simulator. The time taken to recover and the correctness of the recovery procedure served as the objective evaluation measures. A Likert-type rating scale and open-ended subject matter expert opinions served as the subjective measures of evaluation. To examine whether there was a relationship between usability of the attitude indicator and difficulty of the unusual attitude, the workload levels involved in performing the unusual attitude recoveries were grouped into three levels, low, medium, and high. At each workload level there were four conditions, for a total of 12 different conditions. Each pilot was asked to recovery twice from each condition, for a total of 24 unusual attitude recovery trials. The test trials were counterbalanced and displayed in a prearranged order. No differences due to difficulty of the unusual attitude were detected. Overall, the study revealed that the Sky Arc led to generally faster recoveries than did the standard display, as well as higher subjective preference ratings

  12. Visualization of cortical, subcortical and deep brain neural circuit dynamics during naturalistic mammalian behavior with head-mounted microscopes and chronically implanted lenses.

    PubMed

    Resendez, Shanna L; Jennings, Josh H; Ung, Randall L; Namboodiri, Vijay Mohan K; Zhou, Zhe Charles; Otis, James M; Nomura, Hiroshi; McHenry, Jenna A; Kosyk, Oksana; Stuber, Garret D

    2016-03-01

    Genetically encoded calcium indicators for visualizing dynamic cellular activity have greatly expanded our understanding of the brain. However, owing to the light-scattering properties of the brain, as well as the size and rigidity of traditional imaging technology, in vivo calcium imaging has been limited to superficial brain structures during head-fixed behavioral tasks. These limitations can now be circumvented by using miniature, integrated microscopes in conjunction with an implantable microendoscopic lens to guide light into and out of the brain, thus permitting optical access to deep brain (or superficial) neural ensembles during naturalistic behaviors. Here we describe steps to conduct such imaging studies using mice. However, we anticipate that the protocol can be easily adapted for use in other small vertebrates. Successful completion of this protocol will permit cellular imaging of neuronal activity and the generation of data sets with sufficient statistical power to correlate neural activity with stimulus presentation, physiological state and other aspects of complex behavioral tasks. This protocol takes 6-11 weeks to complete.

  13. Using EMG to anticipate head motion for virtual-environment applications

    NASA Technical Reports Server (NTRS)

    Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

    2005-01-01

    In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

  14. Military market for flat panel displays

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    1997-07-01

    This paper addresses the number, function and size of primary military displays and establishes a basis to determine the opportunities for technology insertion in the immediate future and into the next millennium. The military displays market is specified by such parameters as active area and footprint size, and other characteristics such as luminance, gray scale, resolution, color capability and night vision imaging system capability. A select grouping of funded, future acquisitions, planned and predicted cockpit kits, and form-fit-function upgrades are taken into account. It is the intent of this paper to provide an overview of the DoD niche market, allowing both government and industry a timely reference to insure meeting DoD requirements for flat-panel displays on schedule and in a cost-effective manner. The aggregate DoD market for direct view displays is presently estimated to be in excess of 157,000. Helmet/head mounted displays will add substantially to this total. The vanishing vendor syndrome for older display technologies is becoming a growing, pervasive problem throughout DoD, which consequently just leverage the more modern display technologies being developed for civil-commercial markets.

  15. Virtual displays for entertainment applications: hitting cost/performance with LED arrays

    NASA Astrophysics Data System (ADS)

    Karpman, Maurice S.; Wells, Ben A.

    1997-01-01

    Virtual displays have tremendous potential in entertainment applications such as video games, head mount displays for personal computers, and mobile World Wide Web viewers. These consumer applications require high quality virtual displays at a cost below $40 per eye. This combination of performance and cost is not realizable with virtual displays based on LCDs or CRTs. However, low cost, high quality virtual displays can be achieved using patented scanned linear array technology and red, green and blue monolithic LED arrays. A 384 by 224 full color virtual display prototype has been built using this approach. The prototype delivers 4-bits of grayscale per color and flicker-free performance at a 60 Hz frame refresh rate. This paper discuses details of our LED based full color virtual display prototype; development of red, green and blue monolithic LED arrays; and work-in- progress to miniaturize the display and scale the resolution to full VGA.

  16. Integrative Advances for OCT-Guided Ophthalmic Surgery and Intraoperative OCT: Microscope Integration, Surgical Instrumentation, and Heads-Up Display Surgeon Feedback

    PubMed Central

    Ehlers, Justis P.; Srivastava, Sunil K.; Feiler, Daniel; Noonan, Amanda I.; Rollins, Andrew M.; Tao, Yuankai K.

    2014-01-01

    Purpose To demonstrate key integrative advances in microscope-integrated intraoperative optical coherence tomography (iOCT) technology that will facilitate adoption and utilization during ophthalmic surgery. Methods We developed a second-generation prototype microscope-integrated iOCT system that interfaces directly with a standard ophthalmic surgical microscope. Novel features for improved design and functionality included improved profile and ergonomics, as well as a tunable lens system for optimized image quality and heads-up display (HUD) system for surgeon feedback. Novel material testing was performed for potential suitability for OCT-compatible instrumentation based on light scattering and transmission characteristics. Prototype surgical instruments were developed based on material testing and tested using the microscope-integrated iOCT system. Several surgical maneuvers were performed and imaged, and surgical motion visualization was evaluated with a unique scanning and image processing protocol. Results High-resolution images were successfully obtained with the microscope-integrated iOCT system with HUD feedback. Six semi-transparent materials were characterized to determine their attenuation coefficients and scatter density with an 830 nm OCT light source. Based on these optical properties, polycarbonate was selected as a material substrate for prototype instrument construction. A surgical pick, retinal forceps, and corneal needle were constructed with semi-transparent materials. Excellent visualization of both the underlying tissues and surgical instrument were achieved on OCT cross-section. Using model eyes, various surgical maneuvers were visualized, including membrane peeling, vessel manipulation, cannulation of the subretinal space, subretinal intraocular foreign body removal, and corneal penetration. Conclusions Significant iterative improvements in integrative technology related to iOCT and ophthalmic surgery are demonstrated. PMID:25141340

  17. Near-to-eye display concepts for air traffic controllers

    NASA Astrophysics Data System (ADS)

    Ruffner, John W.; Fulbrook, Jim E.; Foglia, Marc

    2004-09-01

    Tower controllers are responsible for maintaining safe separation between airborne aircraft in the airport traffic control area, and separation between aircraft, equipment, and personnel on the airport surface. The objective of this project was to develop and demonstrate an out-the-window, augmented viewing system concept for Air Force air traffic control tower personnel to reduce look-down time within the tower and to optimize visual airfield operations, particularly during limited visibility conditions. We characterized controller tasks where a near-to-eye display greatly aids performance and identified form factor variables that influence user acceptability of hardware configurations. We developed an "out-the-window concept of operation" and analyzed the hardware requirements and feasibility of three near-to-eye viewing systems: two head-mounted monocular displays (HMMD) and a held-to-head binocular display (HHBD). When fully developed, these display prototypes should enhance tower controller situation awareness, and reduce such distractions as having to frequently attend to and respond to head-down (console) display information. There are potential users of this display concept in all branches of the military services, and in the commercial sector. There is also potential utility for surface surveillance operations in support of homeland security, law enforcement personnel, rescue workers, firefighters, and special operations forces in non-aviation applications.

  18. Mount St. Helens Rebirth

    NASA Technical Reports Server (NTRS)

    2002-01-01

    could be seen falling from the sky over the Great Plains, more than 1500 km distant. This image was acquired by Landsat 7 on Aug. 22, 1999. It was produced at 30-m resolution using bands 3, 2, and 1 to display red, green, and blue, respectively ('true color'). Some of the effects of the massive eruption on May 18, 1980, can still be seen clearly, especially on the northern and eastern flanks of Mount St. Helens, which are still mostly barren (shades of white and gray). The crater is in the center of the image. Note the streaking from the crater (gray on the image). These are the remnants of pyroclastic flows (superheated avalanches of gas, ash and pieces of rock) that carved deep channels down the slopes and onto the relatively flat areas near the base of the mountain. The partially-filled Spirit Lake can be seen just to the northeast of the crater (blue-black on the image), and the where most of the energy was directed during the blast is the gray area immediately to the northwest of the crater. However, on other parts of the mountain, the rejuvenation process is obvious. Ash deposits have supplied minerals which have accelerated vegetation growth (various shades of green). Though far from what it looked like 20 years ago, Mount St Helens is actively recovering. Data courtesy Landsat 7 project and EROS Data Center. Caption by James Foster, NASA Goddard Space Flight Center.

  19. Head-aimed vision system improves tele-operated mobility

    NASA Astrophysics Data System (ADS)

    Massey, Kent

    2004-12-01

    A head-aimed vision system greatly improves the situational awareness and decision speed for tele-operations of mobile robots. With head-aimed vision, the tele-operator wears a head-mounted display and a small three axis head-position measuring device. Wherever the operator looks, the remote sensing system "looks". When the system is properly designed, the operator's occipital lobes are "fooled" into believing that the operator is actually on the remote robot. The result is at least a doubling of: situational awareness, threat identification speed, and target tracking ability. Proper system design must take into account: precisely matching fields of view; optical gain; and latency below 100 milliseconds. When properly designed, a head-aimed system does not cause nausea, even with prolonged use.

  20. Head tracker evaluation utilizing the dynamic tracker test fixture

    NASA Astrophysics Data System (ADS)

    La Moure Shattuck, Judson, III; Parisi, Vincent M., II; Smerdon, Arryn J.

    2007-04-01

    In military aviation, head tracker technologies have become increasingly important to track the pilot's head position and orientation, allowing the user to quickly interact with the operational environment. This technology allows the pilot to quickly acquire items of interest and see Fighter Data Link type information. Acquiring the target on a helmet-mounted tracker/display which can automatically slew a weapon's seeker is far more efficient than having to point at the target with the nose of the aircraft as previously required for the heads-up display (HUD) type of target acquisition. The United States Air Force (USAF) has used and evaluated a variety of helmet-mounted trackers for incorporation into their high performance aircrafts. The Dynamic Tracker Test Fixture (DTTF) was designed by the Helmet-Mounted Sensory Technology (HMST) laboratory to accurately measure rotation in one plane both static and dynamic conditions for the purpose of evaluating the accuracy of head trackers, including magnetic, inertial, and optical trackers. This paper describes the design, construction, capabilities, limitations, and performance of the DTTF.

  1. Display science and technology for defense and security

    NASA Astrophysics Data System (ADS)

    Hopper, Darrel G.

    2004-02-01

    The defense display science and technology (S&T) program must address problems facing warfighters that the commercial world will not. These problems require the creation of revolutionary display materials and devices, and the invention of visual system technologies. Breakthroughs needed in display technology for defense and security personnel may be organized into the following technical challenge areas: ultraresolution 25 megapixel devices and 300 megapixel systems (wall display systems at monitor pixel density), flexible plastic rollup displays (ultra-compact form factor when not in use), sparse data true-3D monitors (phosphors embedded in special polymer host matrices), virtual image and head mounted systems, wireless wearable video displays with ultra low weight and volume (including batteries), and intelligent displays with embedded chips providing integrated computing and communications functionalities. Organic photonics and electronics are central to the progress in these S&T challenge areas: significant materials progress is required to enable the display device capabilities required. These challenges and the results of a Department of Defense (DoD) Special Technology Area Review (STAR) on Displays are reviewed. A top-level roadmap is provided to summarize the defense and security S&T strategy.

  2. PV module mounting method and mounting assembly

    DOEpatents

    Lenox, Carl J.S.; Johnson, Kurt M.

    2013-04-23

    A method for mounting PV modules to a deck includes selecting PV module layout pattern so that adjacent PV module edges are spaced apart. PV mounting and support assemblies are secured to the deck according to the layout pattern using fasteners extending into the deck. The PV modules are placed on the PV mounting and support assemblies. Retaining elements are located over and secured against the upper peripheral edge surfaces of the PV modules so to secure them to the deck with the peripheral edges of the PV modules spaced apart from the deck. In some examples a PV module mounting assembly, for use on a shingled deck, comprises flashing, a base mountable on the flashing, a deck-penetrating fastener engageable with the base and securable to the deck so to secure the flashing and the base to the shingled deck, and PV module mounting hardware securable to the base.

  3. A Multiple Model Approach to Track Head Orientation With Delta Quaternions.

    PubMed

    Himberg, Henry; Motai, Yuichi; Bradley, Arthur

    2013-02-01

    Virtual reality and augmented reality environments using helmet-mounted displays create a sense of immersion by closely coupling user head motion to display content. Delays in the presentation of visual information can destroy the sense of presence in the simulation environment when it causes a lag in the display response to user head motion. The effect of display lag can be minimized by predicting head orientation, allowing the system to have sufficient time to counteract the delay. In this paper, anew head orientation prediction technique is proposed that uses a multiple delta quaternion (DQ) extended Kalman filter to track angular head velocity and angular head acceleration. This method is independent of the device used for orientation measurement, relying on quaternion orientation as the only measurement data. A new orientation prediction algorithm is proposed that estimates future head orientation as a function of the current orientation measurement and a predicted change in orientation, using the velocity and acceleration estimates. Extensive experimentation shows that the new method improves head orientation prediction when compared to single filter DQ prediction.

  4. Display requirements for synthetic vision in the military cockpit

    NASA Astrophysics Data System (ADS)

    French, Guy A.; Snow, Michael P.; Hopper, Darrel G.

    2001-09-01

    The term synthetic vision is used to describe combinations of sensor-based imagery (e.g., forward-looking infrared, millimeter-wave radar, light amplification or night vision systems) and imagery based on databases (e.g., digital terrain elevation data, obstacle and obstruction data, approach path data). While sensor-based imagery (often referred to as enhanced vision) has been available in military cockpits for several years, imagery based on databases (often referred to as artificial vision) has not. This paper discusses the display requirements needed for combinations of enhanced and artificial vision in military cockpits. We briefly survey current efforts to achieve synthetic vision displays in both military and civilian cockpits and the costs and benefits of these efforts. The relative advantages and disadvantages of enhanced and artificial vision are discussed within the context of current and future display capabilities, focusing on the human factors of these displays. A sampling of synthetic vision formats envisioned for use in military and civilian cockpits is presented to illustrate what might be required of head-down, head-up, and helmet-mounted displays in terms of resolution, luminance, and color. Further discussion is given to how these display requirements might be altered by aircraft mission, type, and the need to compensate for varying visibility and laser threat conditions.

  5. Magnetic core mounting system

    DOEpatents

    Ronning, Jeffrey J.

    2002-01-01

    A mounting apparatus for an electromagnetic device such as a transformer of inductor includes a generally planar metallic plate as a first heat sink, and a metallic mounting cup as a second heat sink. The mounting cup includes a cavity configured to receive the electromagnetic device, the cavity being defined by a base, and an axially-extending annular sidewall extending from the base to a flange portion of the mounting cup. The mounting cup includes first and second passages for allowing the leads of first and second windings of the electromagnetic device to be routed out of the cavity. The cavity is filled with a polyurethane potting resin, and the mounting cup, including the potted electromagnetic device, is mounted to the plate heat sink using fasteners. The mounting cup, which surrounds the electromagnetic device, in combination with the potting resin provides improved thermal transfer to the plate heat sink, as well as providing resistance to vibration and shocks.

  6. Display system optics II; Proceedings of the Meeting, Orlando, FL, Mar. 30, 31, 1989

    SciTech Connect

    Assenheim, H.M.

    1989-01-01

    Papers on display system optics are presented covering topics such as human factors and night vision systems flight, a peripheral vision display, cockpit vertical situation displays, a prototype near-IR projection system, the effect of a helmet-mounted display on the operator, radial parallax binocular three-dimensional imaging, telepresence systems, and the cockpit man-machine interface. Additional topics include eye-centered interferometric laser projection, laser filters, thin film technologies in active matrix addressing systems of LCDs, supertwisted nematic LCD geometry with improved response times and characteristics, a full color active-matrix LCD in the cockpit environment, polysilicon active-matrix LCDs for cockpit applications, and a dynamic color model for a liquid crystal shutter display. Other topics include a flat fluorescent lamp for LCD back-lighting, holographic combiner design to obtain uniform symbol brightness at a head-up display video camera, vision restriction devices, passive binarization methods for image display and computer-generated holograms, a prismatic combiner for head-up displays, holographic optical elements, multifunction displays optimized for viewability, and technologies for brighter color CRT displays.

  7. Projection-type see-through holographic three-dimensional display

    PubMed Central

    Wakunami, Koki; Hsieh, Po-Yuan; Oi, Ryutaro; Senoh, Takanori; Sasaki, Hisayuki; Ichihashi, Yasuyuki; Okui, Makoto; Huang, Yi-Pai; Yamamoto, Kenji

    2016-01-01

    Owing to the limited spatio-temporal resolution of display devices, dynamic holographic three-dimensional displays suffer from a critical trade-off between the display size and the visual angle. Here we show a projection-type holographic three-dimensional display, in which a digitally designed holographic optical element and a digital holographic projection technique are combined to increase both factors at the same time. In the experiment, the enlarged holographic image, which is twice as large as the original display device, projected on the screen of the digitally designed holographic optical element was concentrated at the target observation area so as to increase the visual angle, which is six times as large as that for a general holographic display. Because the display size and the visual angle can be designed independently, the proposed system will accelerate the adoption of holographic three-dimensional displays in industrial applications, such as digital signage, in-car head-up displays, smart-glasses and head-mounted displays. PMID:27694975

  8. Projection-type see-through holographic three-dimensional display

    NASA Astrophysics Data System (ADS)

    Wakunami, Koki; Hsieh, Po-Yuan; Oi, Ryutaro; Senoh, Takanori; Sasaki, Hisayuki; Ichihashi, Yasuyuki; Okui, Makoto; Huang, Yi-Pai; Yamamoto, Kenji

    2016-10-01

    Owing to the limited spatio-temporal resolution of display devices, dynamic holographic three-dimensional displays suffer from a critical trade-off between the display size and the visual angle. Here we show a projection-type holographic three-dimensional display, in which a digitally designed holographic optical element and a digital holographic projection technique are combined to increase both factors at the same time. In the experiment, the enlarged holographic image, which is twice as large as the original display device, projected on the screen of the digitally designed holographic optical element was concentrated at the target observation area so as to increase the visual angle, which is six times as large as that for a general holographic display. Because the display size and the visual angle can be designed independently, the proposed system will accelerate the adoption of holographic three-dimensional displays in industrial applications, such as digital signage, in-car head-up displays, smart-glasses and head-mounted displays.

  9. Slim near-eye display using pinhole aperture arrays.

    PubMed

    Akşit, Kaan; Kautz, Jan; Luebke, David

    2015-04-10

    We report a new technique for building a wide-angle, lightweight, thin-form-factor, cost-effective, easy-to-manufacture near-eye head-mounted display (HMD) for virtual reality applications. Our approach adopts an aperture mask containing an array of pinholes and a screen as a source of imagery. We demonstrate proof-of-concept HMD prototypes with a binocular field of view (FOV) of 70°×45°, or total diagonal FOV of 83°. This FOV should increase with increasing display panel size. The optical angular resolution supported in our prototype can go down to 1.4-2.1 arcmin by adopting a display with 20-30 μm pixel pitch. PMID:25967333

  10. Fixed mount wavefront sensor

    DOEpatents

    Neal, Daniel R.

    2000-01-01

    A rigid mount and method of mounting for a wavefront sensor. A wavefront dissector, such as a lenslet array, is rigidly mounted at a fixed distance relative to an imager, such as a CCD camera, without need for a relay imaging lens therebetween.

  11. Improved layer-based method for rapid hologram generation and real-time interactive holographic display applications.

    PubMed

    Chen, J-S; Chu, D P

    2015-07-13

    Layer-based method has been proposed as an efficient approach to calculate holograms for holographic image display. This paper further improves its calculation speed and depth cues quality by introducing three different techniques, an improved coding scheme, a multilayer depth- fused 3D method and a fraction method. As a result the total computation time is reduced more than 4 times, and holographic images with accommodation cue are calculated in real time to interactions with the displayed image in a proof-of-concept setting of head-mounted holographic displays.

  12. Photovoltaic module mounting system

    SciTech Connect

    Miros, Robert H. J.; Mittan, Margaret Birmingham; Seery, Martin N; Holland, Rodney H

    2012-09-18

    A solar array mounting system having unique installation, load distribution, and grounding features, and which is adaptable for mounting solar panels having no external frame. The solar array mounting system includes flexible, pedestal-style feet and structural links connected in a grid formation on the mounting surface. The photovoltaic modules are secured in place via the use of attachment clamps that grip the edge of the typically glass substrate. The panel mounting clamps are then held in place by tilt brackets and/or mid-link brackets that provide fixation for the clamps and align the solar panels at a tilt to the horizontal mounting surface. The tilt brackets are held in place atop the flexible feet and connected link members thus creating a complete mounting structure.

  13. Photovoltaic module mounting system

    SciTech Connect

    Miros, Robert H. J.; Mittan, Margaret Birmingham; Seery, Martin N.; Holland, Rodney H.

    2012-04-17

    A solar array mounting system having unique installation, load distribution, and grounding features, and which is adaptable for mounting solar panels having no external frame. The solar array mounting system includes flexible, pedestal-style feet and structural links connected in a grid formation on the mounting surface. The photovoltaic modules are secured in place via the use of attachment clamps that grip the edge of the typically glass substrate. The panel mounting clamps are then held in place by tilt brackets and/or mid-link brackets that provide fixation for the clamps and align the solar panels at a tilt to the horizontal mounting surface. The tilt brackets are held in place atop the flexible feet and connected link members thus creating a complete mounting structure.

  14. A method for generating enhanced vision displays using OpenGL video texture

    NASA Astrophysics Data System (ADS)

    Bernier, Kenneth L.

    2010-04-01

    Degraded visual conditions can marvel the curious and destroy the unprepared. While navigation instruments are trustworthy companions, true visual reference remains king of the hills. Poor visibility may be overcome via imaging sensors such as low light level charge-coupled-device, infrared, and millimeter wave radar. Enhanced Vision systems combine this imagery into a comprehensive situation awareness display, presented to the pilot as reference imagery on a cockpit display, or as world-conformal imagery on head-up or head-mounted displays. This paper demonstrates that Enhanced Vision imaging can be achieved at video rates using typical CPU / GPU architecture, standard video capture hardware, dynamic non-linear ray tracing algorithms, efficient image transfer methods, and simple OpenGL rendering techniques.

  15. Evaluation of ejection safety for the joint helmet-mounted cueing system

    NASA Astrophysics Data System (ADS)

    Barnaba, James M.; Kirk, William K.

    1999-07-01

    Aircrew safety is paramount in the design of a helmet-mounted display (HMD). For the tactical aircrew, ensuring a successful ejection presents significant design challenges. The Joint Helmet Mounted Cueing System (JHMCS) Integrated Product Team (IPT) has been evaluating Vision Systems International's HMD design for aircrew protection in this environment. The JHMCS IPT has developed a set of test objectives in concert with acquisition reform to demonstrate ejection compatibility of the JHMCS. This testing series will be discussed, and will include windblast, ejection tower, and sled and in-flight ejection testing, findings and design impacts. JHMCS performance parameters evaluated include structural integrity, facial and head protection, neck tensile loads, ejection seat and crew equipment compatibility, and mechanical functionality. The design environment for the JHMCS currently is both small and large, male and female aircrew withstanding a successful 450-knot ejection in any of four current USAF & USN tactical aircraft platforms.

  16. High bandwidth optical mount

    DOEpatents

    Bender, D.A.; Kuklo, T.

    1994-11-08

    An optical mount, which directs a laser beam to a point by controlling the position of a light-transmitting optic, is stiffened so that a lowest resonant frequency of the mount is approximately one kilohertz. The optical mount, which is cylindrically-shaped, positions the optic by individually moving a plurality of carriages which are positioned longitudinally within a sidewall of the mount. The optical mount is stiffened by allowing each carriage, which is attached to the optic, to move only in a direction which is substantially parallel to a center axis of the optic. The carriage is limited to an axial movement by flexures or linear bearings which connect the carriage to the mount. The carriage is moved by a piezoelectric transducer. By limiting the carriage to axial movement, the optic can be kinematically clamped to a carriage. 5 figs.

  17. High bandwidth optical mount

    DOEpatents

    Bender, Donald A.; Kuklo, Thomas

    1994-01-01

    An optical mount, which directs a laser beam to a point by controlling the position of a light-transmitting optic, is stiffened so that a lowest resonant frequency of the mount is approximately one kilohertz. The optical mount, which is cylindrically-shaped, positions the optic by individually moving a plurality of carriages which are positioned longitudinally within a sidewall of the mount. The optical mount is stiffened by allowing each carriage, which is attached to the optic, to move only in a direction which is substantially parallel to a center axis of the optic. The carriage is limited to an axial movement by flexures or linear bearings which connect the carriage to the mount. The carriage is moved by a piezoelectric transducer. By limiting the carriage to axial movement, the optic can be kinematically clamped to a carriage.

  18. Low-cost color LCD helmet display

    NASA Astrophysics Data System (ADS)

    Leinenwever, Roger; Best, Leonard G.; Ericksen, Bryce J.

    1992-10-01

    The goal of this helmet-mounted display (HMD) project was development and demonstration of a low-cost color display incorporating see-through optics. A full field-of-regard visual presentation was to be provided through the use of a head-tracker system and the HMD was to be suitable for use with low-cost cockpit trainers. The color imaging devices selected for the project are commercially available liquid crystal display (LCD) panels. The LCDs are 3.0 inch (diagonal) thin film transistor (TFT) types using a delta format for the red, green, blue (RGB) matrix. Fiber optic light panels mounted behind the LCDs provide a cool light source of greater than 3400 foot-lamberts (ft-L). Approximately 3 percent of the applied light source is emitted by the LCD image source. The video displayed is in a 3:4 format representing a 30 degree(s) vertical by 40 degree(s) horizontal biocular instantaneous field-of-view (IFOV) visual image from a graphic image generation system and is controlled in a full field of regard based on positional information from a head-tracker system. The optical elements of the HMD are designed as an exit pupil forming, see-through system and require the eye to be in a 15 mm volume for viewing the scene. The beam splitting function of the optics allows the user to see through the optics for reading cockpit instrumentation, while viewing outside the cockpit reveals the out-the-window (OTW) scene. The optic design allows for the IFOV to be displayed through a set of field lens, relay lens, folding mirror, beam splitter and spherical mirror system. The beam splitters and spherical mirrors for both optical paths are coated for approximately 50 percent transmission and reflectance. This approach, combined with the losses through the rest of the optical path, provides a theoretical maximum of 10.9 percent of the LCD image source intensity arriving at the eye. Initial tests of image intensity at the eye for a full white scene have measured at approximately 11 ft-L.

  19. Display standards for commercial flight decks

    NASA Astrophysics Data System (ADS)

    Lamberth, Larry S.; Penn, Cecil W.

    1994-06-01

    SAE display standards are used as guidelines for certifying commercial airborne electronic displays. The SAE document generation structure and approval process is described. The SAE committees that generate display standards are described. Three SAE documents covering flat panel displays (AS-8034, ARP-4256, and ARP-4260) are discussed with their current status. Head-Up Display documents are also in work.

  20. Liner mounting assembly

    NASA Technical Reports Server (NTRS)

    Halila, Ely E. (Inventor)

    1994-01-01

    A mounting assembly includes an annular supporting flange disposed coaxially about a centerline axis which has a plurality of circumferentially spaced apart supporting holes therethrough. An annular liner is disposed coaxially with the supporting flange and includes a plurality of circumferentially spaced apart mounting holes aligned with respective ones of the supporting holes. Each of a plurality of mounting pins includes a proximal end fixedly joined to the supporting flange through a respective one of the supporting holes, and a distal end disposed through a respective one of the liner mounting holes for supporting the liner to the supporting flange while unrestrained differential thermal movement of the liner relative to the supporting flange.

  1. Fitness activity classification by using multiclass support vector machines on head-worn sensors.

    PubMed

    Loh, Darrell; Lee, Tien J; Zihajehzadeh, Shaghayegh; Hoskinson, Reynald; Park, Edward J

    2015-08-01

    Fitness activity classification on wearable devices can provide activity-specific information and generate more accurate performance metrics. Recently, optical head-mounted displays (OHMD) like Google Glass, Sony SmartEyeglass and Recon Jet have emerged. This paper presents a novel method to classify fitness activities using head-worn accelerometer, barometric pressure sensor and GPS, with comparisons to other common mounting locations on the body. Using multiclass SVM on head-worn sensors, we obtained an average F-score of 96.66% for classifying standing, walking, running, ascending/descending stairs and cycling. The best sensor location combinations were found to be on the ankle plus another upper body location. Using three or more sensors did not show a notable improvement over the best two-sensor combinations. PMID:26736309

  2. Multispectral image-fused head-tracked vision system (HTVS) for driving applications

    NASA Astrophysics Data System (ADS)

    Reese, Colin E.; Bender, Edward J.

    2001-08-01

    Current military thermal driver vision systems consist of a single Long Wave Infrared (LWIR) sensor mounted on a manually operated gimbal, which is normally locked forward during driving. The sensor video imagery is presented on a large area flat panel display for direct view. The Night Vision and Electronics Sensors Directorate and Kaiser Electronics are cooperatively working to develop a driver's Head Tracked Vision System (HTVS) which directs dual waveband sensors in a more natural head-slewed imaging mode. The HTVS consists of LWIR and image intensified sensors, a high-speed gimbal, a head mounted display, and a head tracker. The first prototype systems have been delivered and have undergone preliminary field trials to characterize the operational benefits of a head tracked sensor system for tactical military ground applications. This investigation will address the advantages of head tracked vs. fixed sensor systems regarding peripheral sightings of threats, road hazards, and nearby vehicles. An additional thrust will investigate the degree to which additive (A+B) fusion of LWIR and image intensified sensors enhances overall driving performance. Typically, LWIR sensors are better for detecting threats, while image intensified sensors provide more natural scene cues, such as shadows and texture. This investigation will examine the degree to which the fusion of these two sensors enhances the driver's overall situational awareness.

  3. Mounting for windmills

    SciTech Connect

    Allison, W. D.

    1980-08-12

    A windmill structure includes a mounting for supporting one or a large number of windmills in an elevated position above the ground so that the windmills can weathercock and align with the wind. The mounting arrangement limits movement continuously in one direction and returns the windmill to its original position.

  4. Stable mirror mount

    DOEpatents

    Cutburth, R.W.

    1983-11-04

    An improved mirror mount assembly is disclosed. The mirror mount assembly provides a post assembly slidable in a Y-axis orientation and a nut plate assembly slidable in an X-axis orientation and means for simultaneously locking said post assembly and said key assembly in a fixed position.

  5. Stable mirror mount

    DOEpatents

    Cutburth, Ronald W.

    1990-01-01

    An improved mirror mount assembly is disclosed. The mirror mount assembly provides a post assembly slidable in a Y-axis orientation and a nut plate assembly slidable in an X-axis orientation and a device for simultaneously locking the post assembly and the key assembly in a fixed position.

  6. Thermistor mount efficiency calibration

    SciTech Connect

    Cable, J.W.

    1980-05-01

    Thermistor mount efficiency calibration is accomplished by use of the power equation concept and by complex signal-ratio measurements. A comparison of thermistor mounts at microwave frequencies is made by mixing the reference and the reflected signals to produce a frequency at which the amplitude and phase difference may be readily measured.

  7. Spherical mirror mount

    NASA Technical Reports Server (NTRS)

    Meyer, Jay L. (Inventor); Messick, Glenn C. (Inventor); Nardell, Carl A. (Inventor); Hendlin, Martin J. (Inventor)

    2011-01-01

    A spherical mounting assembly for mounting an optical element allows for rotational motion of an optical surface of the optical element only. In that regard, an optical surface of the optical element does not translate in any of the three perpendicular translational axes. More importantly, the assembly provides adjustment that may be independently controlled for each of the three mutually perpendicular rotational axes.

  8. A case study of new assessment and training of unilateral spatial neglect in stroke patients: effect of visual image transformation and visual stimulation by using a head mounted display system (HMD)

    PubMed Central

    2010-01-01

    Background Unilateral spatial neglect (USN) is most damaging to an older stroke patient who also has a lower performance in their activities of daily living or those elderly who are still working. The purpose of this study was to understand more accurately pathology of USN using a new HMD system. Methods Two stroke patients (Subject A and B) participated in this study after gaining their informed consent and they all had Left USN as determined by clinical tests. Assessments of USN were performed by using the common clinical test (the line cancellation test) and six special tests by using HMD system in the object-centered coordinates (OC) condition and the egocentric coordinates (EC) condition. OC condition focused the test sheet only by a CCD. EC condition was that CCD can always follow the subject's movement. Moreover, the study focused on the effect of the reduced image condition of real image and the arrows. Results In Patient A who performed the common test and special tests of OC and EC conditions, the results showed that for the line cancellation test under the common condition, both of the percentage of the correct answers at the right and left sides in the test sheet was 100 percent. However, in the OC condition, the percentage of the correct answers at the left side in the test sheet was 44 percent and the right side was 94 percent. In the EC condition, the left side was 61 percent and the right side was 67 percent. In Patient B, according to the result of the use of reduced image condition and the arrows condition by HMD system, these line cancellation scores more increased than the score of the common test. Conclusions The results showed that the assessment of USN using an HMD system may clarify the left neglect area which cannot be easily observed in the clinical evaluation for USN. HMD may be able to produce an artificially versatile environment as compared to the common clinical evaluation and treatment. PMID:20470434

  9. NIF small mirror mounts

    NASA Astrophysics Data System (ADS)

    McCarville, Tom J.

    1999-11-01

    The most prominent physical characteristics of the 192-beam NIF laser are the 123 m length of the main laser and 400 mm aperture of each beam line. The main laser is illustrated in Figure 1, which shows half the total beam lines. Less visible are the many small optics (less than 100-mm diameter) used to align and diagnose each beam line. Commercial mounts can be used for most of the small aperture turning mirrors. This paper reviews the NIF projects effort to identify suitable commercial mirror mounts. The small mirror mounts have stability, wave front, space, and cleanliness requirements similar to the large aperture optics. While cost favors use of commercial mounts, there is little other than user experience to guide the mount qualification process. At present, there is no recognizable qualification standard with which to compare various products. In a large project like NIF, different user experience leads to different product selection. In some cases the differences are justified by application needs, but more often the selection process is somewhat random due to a lack of design standards. The result is redundant design and testing by project staff and suppliers. Identification of suitable mirror mounts for large projects like NIF would be streamlined if standards for physical and performance criteria were available, reducing cost for both the project and suppliers. Such standards could distinguish mounts for performance critical applications like NIF from laboratory applications, where ease of use and flexibility is important.

  10. Enhanced spatial-state feedback for night-vision goggle displays

    NASA Astrophysics Data System (ADS)

    Bachelder, Edward N.; Hansman, R. John, Jr.

    1997-06-01

    A preliminary study was conducted to investigate the use of visual flow cues as an aid to ground and vertical drift awareness during helicopter flight and targeting while using night vision goggles (NVGs). Three displays wee compared: (1) NVG display: simulated NVG image of cockpit and external environment. (2) Overlay display: NVG image with an overlay display but with symbology flow cue field and a surrounding wire-frame globe; (3) Cut-out display: same as the overlay display but with symbology removed from the central region. Three levels of contrast were also compared using each display type. The visual scenery was displayed to subjects using a helmet-mounted virtual reality device that had a 40 by 50 degree field-of-view liquid crystal display. The study involved six pilots. Three tasks were given: (1) Search task: designate enemy targets with a helmet-mounted sight; (2) Hover task: null out all transnational and yaw rates while in a hover; (3) Search/Hover task: perform both Search and Hover tasks simultaneously. These tasks were conducted in a fixed-based helicopter simulator which used the dynamics of a small-scale model helicopter. The following performance measures were collected: (1) Pilot ability to detect and recognize targets; (2) Pilots ability to null transnational and yaw rates; (3) Time scanning the instrument panel. Subjects also rated displays for efficacy in completing the three tasks. Target detection scores conducted during the Search and Search/Hover tasks were highest using the NVG display, followed by the cut-out display. Root-mean-square (RMS) drift rate error was comparable for all display types in the Hover and Hover/Search tasks, however RMS control input activity in all the translational axes was significantly higher in both rate-cueing displays than with the NVG display. From the control input and drift rate time histories it appears that the motion cues were more compelling in the overlay and cut- out displays than those perceived

  11. Motion parallax in immersive cylindrical display systems

    NASA Astrophysics Data System (ADS)

    Filliard, N.; Reymond, G.; Kemeny, A.; Berthoz, A.

    2012-03-01

    Motion parallax is a crucial visual cue produced by translations of the observer for the perception of depth and selfmotion. Therefore, tracking the observer viewpoint has become inevitable in immersive virtual (VR) reality systems (cylindrical screens, CAVE, head mounted displays) used e.g. in automotive industry (style reviews, architecture design, ergonomics studies) or in scientific studies of visual perception. The perception of a stable and rigid world requires that this visual cue be coherent with other extra-retinal (e.g. vestibular, kinesthetic) cues signaling ego-motion. Although world stability is never questioned in real world, rendering head coupled viewpoint in VR can lead to the perception of an illusory perception of unstable environments, unless a non-unity scale factor is applied on recorded head movements. Besides, cylindrical screens are usually used with static observers due to image distortions when rendering image for viewpoints different from a sweet spot. We developed a technique to compensate in real-time these non-linear visual distortions, in an industrial VR setup, based on a cylindrical screen projection system. Additionally, to evaluate the amount of discrepancies tolerated without perceptual distortions between visual and extraretinal cues, a "motion parallax gain" between the velocity of the observer's head and that of the virtual camera was introduced in this system. The influence of this artificial gain was measured on the gait stability of free-standing participants. Results indicate that, below unity, gains significantly alter postural control. Conversely, the influence of higher gains remains limited, suggesting a certain tolerance of observers to these conditions. Parallax gain amplification is therefore proposed as a possible solution to provide a wider exploration of space to users of immersive virtual reality systems.

  12. Man-in-the-loop study of filtering in airborne head tracking tasks

    NASA Technical Reports Server (NTRS)

    Lifshitz, S.; Merhav, S. J.

    1992-01-01

    A human-factors study is conducted of problems due to vibrations during the use of a helmet-mounted display (HMD) in tracking tasks whose major factors are target motion and head vibration. A method is proposed for improving aiming accuracy in such tracking tasks on the basis of (1) head-motion measurement and (2) the shifting of the reticle in the HMD in ways that inhibit much of the involuntary apparent motion of the reticle, relative to the target, and the nonvoluntary motion of the teleoperated device. The HMD inherently furnishes the visual feedback required by this scheme.

  13. Defense display market assessment

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    1998-09-01

    This paper addresses the number, function and size of principal military displays and establishes a basis to determine the opportunities for technology insertion in the immediate future and into the next millennium. Principal military displays are defined as those occupying appreciable crewstation real-estate and/or those without which the platform could not carry out its intended mission. DoD 'office' applications are excluded from this study. The military displays market is specified by such parameters as active area and footprint size, and other characteristics such as luminance, gray scale, resolution, angle, color, video capability, and night vision imaging system (NVIS) compatibility. Funded, future acquisitions, planned and predicted crewstation modification kits, and form-fit upgrades are taken into account. This paper provides an overview of the DoD niche market, allowing both government and industry a necessary reference by which to meet DoD requirements for military displays in a timely and cost-effective manner. The aggregate DoD market for direct-view and large-area military displays is presently estimated to be in excess of 242,000. Miniature displays are those which must be magnified to be viewed, involve a significantly different manufacturing paradigm and are used in helmet mounted displays and thermal weapon sight applications. Some 114,000 miniature displays are presently included within Service weapon system acquisition plans. For vendor production planning purposes it is noted that foreign military sales could substantially increase these quantities. The vanishing vendor syndrome (VVS) for older display technologies continues to be a growing, pervasive problem throughout DoD, which consequently must leverage the more modern display technologies being developed for civil- commercial markets.

  14. Mounting for ceramic scroll

    DOEpatents

    Petty, Jack D.

    1993-01-01

    A mounting for a ceramic scroll on a metal engine block of a gas turbine engine includes a first ceramic ring and a pair of cross key connections between the first ceramic ring, the ceramic scroll, and the engine block. The cross key connections support the scroll on the engine block independent of relative radial thermal growth and for bodily movement toward an annular mounting shoulder on the engine. The scroll has an uninterrupted annular shoulder facing the mounting shoulder on the engine block. A second ceramic ring is captured between mounting shoulder and the uninterrupted shoulder on the scroll when the latter is bodily shifted toward the mouting shoulder to define a gas seal between the scroll and the engine block.

  15. Maneuvering impact boring head

    DOEpatents

    Zollinger, W. Thor; Reutzel, Edward W.

    1998-01-01

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

  16. Maneuvering impact boring head

    DOEpatents

    Zollinger, W.T.; Reutzel, E.W.

    1998-08-18

    An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

  17. Three-dimensional visualization and display technologies; Proceedings of the Meeting, Los Angeles, CA, Jan. 18-20, 1989

    NASA Technical Reports Server (NTRS)

    Robbins, Woodrow E. (Editor); Fisher, Scott S. (Editor)

    1989-01-01

    Special attention was given to problems of stereoscopic display devices, such as CAD for enhancement of the design process in visual arts, stereo-TV improvement of remote manipulator performance, a voice-controlled stereographic video camera system, and head-mounted displays and their low-cost design alternatives. Also discussed was a novel approach to chromostereoscopic microscopy, computer-generated barrier-strip autostereography and lenticular stereograms, and parallax barrier three-dimensional TV. Additional topics include processing and user interface isssues and visualization applications, including automated analysis and fliud flow topology, optical tomographic measusrements of mixing fluids, visualization of complex data, visualization environments, and visualization management systems.

  18. Simulator evaluation of display concepts for pilot monitoring and control of space shuttle approach and landing. Phase 2: Manual flight control

    NASA Technical Reports Server (NTRS)

    Gartner, W. B.; Baldwin, K. M.

    1973-01-01

    A study of the display requirements for final approach management of the space shuttle orbiter vehicle is presented. An experimental display concept, providing a more direct, pictorial representation of the vehicle's movement relative to the selected approach path and aiming points, was developed and assessed as an aid to manual flight path control. Both head-up, windshield projections and head-down, panel mounted presentations of the experimental display were evaluated in a series of simulated orbiter approach sequence. Data obtained indicate that the experimental display would enable orbiter pilots to exercise greater flexibility in implementing alternative final approach control strategies. Touchdown position and airspeed dispersion criteria were satisfied on 91 percent of the approach sequences, representing various profile and wind effect conditions. Flight path control and airspeed management satisfied operationally-relevant criteria for the two-segment, power-off orbiter approach and were consistently more accurate and less variable when the full set of experimental display elements was available to the pilot. Approach control tended to be more precise when the head-up display was used; however, the data also indicate that the head-down display would provide adequate support for the manual control task.

  19. The effect of hair density on the coupling between the tactor and the skin of the human head.

    PubMed

    Myles, Kimberly; Kalb, Joel T; Lowery, Janea; Kattel, Bheem P

    2015-05-01

    The purpose of this study was to determine the effect of hair density on vibration detection thresholds associated with the perception of low frequency vibration stimuli applied to the head. A host of tactile sensitivity information exists for other parts of the body, however the same information is lacking for the head. Thirty-three college students, age 18-35, were recruited for the study. A mixed design was used to evaluate the effect of hair density, head location, and frequency on vibration detection thresholds. Results suggest that hair density might slightly impede vibration signals from reaching the scalp and reduce vibration sensitivity, for the least sensitive locations on the head. This research provides design recommendations for head-mounted tactile displays for women and those with hair that can be used to convey directional cues for navigation and as alerts to critical events in the environment.

  20. Low-cost monochrome CRT helmet display

    NASA Astrophysics Data System (ADS)

    Leinenwever, Roger; Best, Leonard G.; Ericksen, Bryce J.

    1992-10-01

    The goal of the cathode ray tube (CRT) helmet-mounted display (HMD) project was development and demonstration of a low-cost monochrome display incorporating see-through optics. The HMD was also to be integrable with a variety of image generation systems and suitable for use with low-cost cockpit trainers and night vision goggles (NVG) training applications. A final goal for the HMD was to provide a full field of regard (FOR) using a head-tracker system. The resultant HMD design included two 1 inch CRTs used with a simple optical design of beam splitters and spherical mirrors. The design provides for approximately 50% transmission and reflectance capabilities for observing the 30 degree(s) vertical X 40 degree(s) horizontal biocular instantaneous field-of-view visual image from a graphic image generator system. This design provides for a theoretical maximum of 10.8% of the CRT image source intensity arriving at the eye. Initial tests of image intensity at the eye for an average out-the-window scene have yielded 12 to 13 Foot Lamberts with the capability of providing approximately 130 Foot Lamberts. Invoking a software 'own ship' mask to 'blackout' the visual image, the user can monitor 'in-cockpit' instrumentation utilizing the see- through characteristics of the optics. The CRTs are operated at a TV line rate with a modulation transfer function (MTF) of approximately 65%. The small beam spot size and the high MTF provide for an enhanced image display. The display electronics are designed to provide a monochrome video picture based on an RS170 video input.

  1. Recent research results in stereo 3-D pictorial displays at Langley Research Center

    NASA Technical Reports Server (NTRS)

    Parrish, Russell V.; Busquets, Anthony M.; Williams, Steven P.

    1990-01-01

    Recent results from a NASA-Langley program which addressed stereo 3D pictorial displays from a comprehensive standpoint are reviewed. The program dealt with human factors issues and display technology aspects, as well as flight display applications. The human factors findings include addressing a fundamental issue challenging the application of stereoscopic displays in head-down flight applications, with the determination that stereoacuity is unaffected by the short-term use of stereo 3D displays. While stereoacuity has been a traditional measurement of depth perception abilities, it is a measure of relative depth, rather than actual depth (absolute depth). Therefore, depth perception effects based on size and distance judgments and long-term stereo exposure remain issues to be investigated. The applications of stereo 3D to pictorial flight displays within the program have repeatedly demonstrated increases in pilot situational awareness and task performance improvements. Moreover, these improvements have been obtained within the constraints of the limited viewing volume available with conventional stereo displays. A number of stereo 3D pictorial display applications are described, including recovery from flight-path offset, helicopter hover, and emulated helmet-mounted display.

  2. Frequency response of helicopter piloth head azimuth, pitch and tilt: approaching engineering specifications

    NASA Astrophysics Data System (ADS)

    Temme, Leonard A.; Still, David L.; Houtsma, Adrianus J. M.

    2006-05-01

    Background: Since helmet mounted displays (HMDs) are slaved to a pilot's head, head motion is important for the design of HMDs and their symbology. This is particularly true since the lateral tilt of a pilot's head changes when the pilot shifts his/her gaze from the horizon visible outside the cockpit to the instruments inside the cockpit. This change in head tilt, which may contribute to episodes of spatial disorientation and possibly dangerous control input reversal errors, is commonly attributed to a neuro-muscular reflex driven by the apparent tilt of the visible horizon, the so-called optokinetic cervical reflex (OKCR). The present paper: (1) describes head motion in the frequency domain, and (2) elaborates a biomechanical explanation for the observed head tilt that is simpler than the neurological OKCR model. Methods: Fourier spectral decompositions were calculated from archived head pitch, tilt, and azimuth data recorded at 10 Hz from four pilots as they executed a slalom maneuver in an AH Mk 7 Linx helicopter. Pilots A through D performed the slalom 11, 12, 8, and 11 times, respectively, for a total of 42 flights. Results: The Fourier decomposition showed that the typical azimuth spectrum differs from that of pitch, and tilt. Discussion: These results provide: (1) spectral descriptions of head azimuth, pitch, and tilt to aid the design of HMD systems, and (2) further support for the biomechanical model of head tilt.

  3. Flight simulator evaluation of display media devices for synthetic vision concepts

    NASA Astrophysics Data System (ADS)

    Arthur, Jarvis J., III; Williams, Steven P.; Prinzel, Lawrence J., III; Kramer, Lynda J.; Bailey, Randall E.

    2004-09-01

    The Synthetic Vision Systems (SVS) Project of the National Aeronautics and Space Administration's (NASA) Aviation Safety Program (AvSP) is striving to eliminate poor visibility as a causal factor in aircraft accidents as well as enhance operational capabilities of all aircraft. To accomplish these safety and capacity improvements, the SVS concept is designed to provide a clear view of the world around the aircraft through the display of computer-generated imagery derived from an onboard database of terrain, obstacle, and airport information. Display media devices with which to implement SVS technology that have been evaluated so far within the Project include fixed field of view head up displays and head down Primary Flight Displays with pilot-selectable field of view. A simulation experiment was conducted comparing these display devices to a fixed field of view, unlimited field of regard, full color Helmet-Mounted Display system. Subject pilots flew a visual circling maneuver in IMC at a terrain-challenged airport. The data collected for this experiment is compared to past SVS research studies.

  4. Flight Simulator Evaluation of Display Media Devices for Synthetic Vision Concepts

    NASA Technical Reports Server (NTRS)

    Arthur, J. J., III; Williams, Steven P.; Prinzel, Lawrence J., III; Kramer, Lynda J.; Bailey, Randall E.

    2004-01-01

    The Synthetic Vision Systems (SVS) Project of the National Aeronautics and Space Administration's (NASA) Aviation Safety Program (AvSP) is striving to eliminate poor visibility as a causal factor in aircraft accidents as well as enhance operational capabilities of all aircraft. To accomplish these safety and capacity improvements, the SVS concept is designed to provide a clear view of the world around the aircraft through the display of computer-generated imagery derived from an onboard database of terrain, obstacle, and airport information. Display media devices with which to implement SVS technology that have been evaluated so far within the Project include fixed field of view head up displays and head down Primary Flight Displays with pilot-selectable field of view. A simulation experiment was conducted comparing these display devices to a fixed field of view, unlimited field of regard, full color Helmet-Mounted Display system. Subject pilots flew a visual circling maneuver in IMC at a terrain-challenged airport. The data collected for this experiment is compared to past SVS research studies.

  5. Heads Up

    MedlinePlus

    ... Juvenil HEADS UP to School Sports Online Concussion Training Coaches Parents Athletes Sports Officials HEADS UP to Schools School Nurses Teachers, Counselors, and School Professionals Parents HEADS UP ...

  6. PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST TOWARDS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST TOWARDS MOUNT BALLYHOO - Naval Operating Base Dutch Harbor & Fort Mears, Ulakta Head Fixed Defense Battery Command Post No. 1, Unalaska, Aleutian Islands, AK

  7. 1. PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. PANORAMA, FROM ULAKTA HEAD COMMAND POST TO THE WEST TOWARD MOUNT BALLYHOO - Naval Operating Base Dutch Harbor & Fort Mears, Ulakta Head Fixed Defense Battery Command Post No. 1, Unalaska, Aleutian Islands, AK

  8. MountPointAttributes

    2001-06-16

    MountPointAttributes is a software component that provides client code with a technique to raise the local namespace of a file to a global namespace. Its abstractions and mechanisms allow the client code to gather global properties of a file and to use them in devising an effective storage access strategy on this file.

  9. Transducer-Mounting Fixture

    NASA Technical Reports Server (NTRS)

    Spiegel, Kirk W.

    1990-01-01

    Transducer-mounting fixture holds transducer securely against stud. Projects only slightly beyond stud after installation. Flanged transducer fits into fixture when hinged halves open. When halves reclosed, fixture tightened onto threaded stud until stud makes contact with transducer. Knurled area on fixture aids in tightening fixture on stud.

  10. Housing And Mounting Structure

    DOEpatents

    Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R.F.; Bryan, Robert P.; Carson, Richard F.; Duckett, III, Edwin B.; McCormick, Frederick B.; Miller, Gregory V.; Peterson, David W.; Smith, Terrance T.

    2005-03-08

    This invention relates to an optical transmitter, receiver or transceiver module, and more particularly, to an apparatus for connecting a first optical connector to a second optical connector. The apparatus comprises: (1) a housing having at least a first end and at least a second end, the first end of the housing capable of receiving the first optical connector, and the second end of the housing capable of receiving the second optical connector; (2) a longitudinal cavity extending from the first end of the housing to the second end of the housing; and (3) an electromagnetic shield comprising at least a portion of the housing. This invention also relates to an apparatus for housing a flexible printed circuit board, and this apparatus comprises: (1) a mounting structure having at least a first surface and a second surface; (2) alignment ridges along the first and second surfaces of the mounting structure, the alignment ridges functioning to align and secure a flexible printed circuit board that is wrapped around and attached to the first and second surfaces of the mounting structure; and (3) a series of heat sink ridges adapted to the mounting structure, the heat sink ridges functioning to dissipate heat that is generated from the flexible printed circuit board.

  11. Analysis of image quality for laser display scanner test

    NASA Astrophysics Data System (ADS)

    Specht, H.; Kurth, S.; Billep, D.; Gessner, T.

    2009-02-01

    The scanning laser display technology is one of the most promising technologies for highly integrated projection display applications (e. g. in PDAs, mobile phones or head mounted displays) due to its advantages regarding image quality, miniaturization level and low cost potential. As a couple of research teams found during their investigations on laser scanning projections systems, the image quality of such systems is - beside from laser source and video signal processing - crucially determined by the scan engine, including MEMS scanner, driving electronics, scanning regime and synchronization. Even though a number of technical parameters can be measured with high accuracy, the test procedure is challenging because the influence of these parameters on image quality is often insufficiently understood. Thus, in many cases it is not clear how to define limiting values for characteristic parameters. In this paper the relationship between parameters characterizing the scan engine and their influence on image quality will be discussed. Those include scanner topography, geometry of the path of light as well as trajectory parameters. Understanding this enables a new methodology for testing and characterization of the scan engine, based on evaluation of one or a series of projected test images. Due to the fact that the evaluation process can be easily automated by digital image processing this methodology has the potential to become integrated into the production process of laser displays.

  12. Issues in simultaneous HMD display of multireference frames for helicopter applications

    NASA Astrophysics Data System (ADS)

    Bachelder, Edward N.; Hansman, R. John, Jr.

    1996-05-01

    A preliminary study was conducted to investigate the use of reference markers found in the head-fixed frame as an aid to reference frame awareness during aircraft flight while using a helmet mounted display. Three reference-cueing displays were compared: (1) Sparse Reference display: all cockpit and airframe markers removed except for the instrument panel, (2) Cockpit Reference display: entire cockpit environment visible, and (3) Geo/Cockpit Reference display: cockpit environment visible with the addition of a surrounding wire-frame globe. The visual scenery was displayed to subjects using a helmet-mounted virtual reality device that had a 40 X 50 degree field of view liquid crystal display. The study involved six pilots. The task was to locate targets from aural alert information. The aural alerts were based in either the Aircraft reference frame (i.e. target clock position relative to the aircraft nose), or the World reference frame (i.e. target bearing). These tasks were conducted while the subject rode through abrupt maneuvering flight at low level in a fixed-based Cobra helicopter simulator. Performance measures of the pilot's ability to discriminate the intended target from secondary targets in the visual field were collected, as well as subjective ratings for each reference display. The Geo/Cockpit Reference display produced the highest target detection scores for both Aircraft and World-reference alerts. The highest overall detection scores were produced when World-referenced alerts were issued while using the Geo/Cockpit display. The Cockpit display scores were higher than the Sparse display's for both alert types. Subjective scores showed pilot preference for the Geo/Cockpit Reference display over the two displays for both Aircraft and World-reference alerts. A secondary exploratory experiment using the same tasking as the initial experiment was also conducted which observed the effect of peripheral cues. Target detection scores for both alert types

  13. A Guide to Making a Display.

    ERIC Educational Resources Information Center

    Gilmour, Frederick T., Comp.

    For media specialists, step-by-step instructions are given for design and construction of classroom and corridor displays. Included are sections on selecting the form, choosing construction materials, covering and mounting, lettering, and utilizing scrap materials. A bibliography lists other books on display building. An appendix lists…

  14. Floating mirror mount

    SciTech Connect

    Koop, D.E.

    1989-01-03

    This patent describes a floating mirror mount for a mirror of a laser is described consisting of: a mirror having a front surface and a back surface, a keeper encircling the mirror and having a peripheral flange engaging the front surface of the mirror when the mirror is not installed in a laser, a retainer positioned rearwardly of the back surface of the mirror and connected to the keeper and having a spring seating surface, spring means engageable with the spring seating surface of the retainer for exerting a resilient biasing force on the mirror, and fastening means for connecting the retainer to the mirror positioning structure of the laser on installation of the mirror mount in the laser.

  15. Horizontally mounted solar collector

    NASA Technical Reports Server (NTRS)

    Black, D. H. (Inventor)

    1979-01-01

    Solar energy is collected by using a vertical deflector assembly, a stationary reflector and a horizontally mounted solar collector. The deflector assembly contains a plurality of vanes which change the direction of the solar energy to the vertical, while constantly keeping the same side of the deflector facing the sun. The vertical rays are then reflected off the stationary reflector and are then absorbed by the collector.

  16. Mount Wilson Observatory

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    Mount Wilson Observatory, located in the San Gabriel Mountains near Pasadena, California, was founded in 1904 by George Ellery Hale with financial support from Andrew Carnegie. In the 1920s and 1930s, working at the 2.5 m Hooker telescope, Edwin Hubble made two of the most important discoveries in the history of astronomy: first, that `nebulae' are actually island universes—galaxies—each with bil...

  17. Monitoring Mount Baker Volcano

    USGS Publications Warehouse

    Malone, S.D.; Frank, D.

    1976-01-01

    Hisotrically active volcanoes in the conterminous United States are restricted to the Cascade Range and extend to the Cascade Range and extend from Mount Baker near the Canadian border to Lassen Peak in northern California. Since 1800 A.D, most eruptive activity has been on a relatively small scale and has not caused loss of life or significant property damage. However, future  volcanism predictably will have more serious effects because of greatly increased use of land near volcanoes during the present century. (See "Appraising Volcanic Hazards of the Cascade Range of the Northwestern United States," Earthquake Inf. Bull., Sept.-Oct. 1974.) The recognition an impending eruption is highly important in order to minimize the potential hazard to people and property. Thus, a substantial increase in hydrothermal activity at Mount Baker in March 1975 ( see "Mount Baker Heating Up," July-Aug. 1975 issue) was regarded as a possible first signal that an eruption might occur, and an intensive monitoring program was undertaken. 

  18. Use of display technologies for augmented reality enhancement

    NASA Astrophysics Data System (ADS)

    Harding, Kevin

    2016-06-01

    Augmented reality (AR) is seen as an important tool for the future of user interfaces as well as training applications. An important application area for AR is expected to be in the digitization of training and worker instructions used in the Brilliant Factory environment. The transition of work instructions methods from printed pages in a book or taped to a machine to virtual simulations is a long step with many challenges along the way. A variety of augmented reality tools are being explored today for industrial applications that range from simple programmable projections in the work space to 3D displays and head mounted gear. This paper will review where some of these tool are today and some of the pros and cons being considered for the future worker environment.

  19. Ocular vergence measurement in projected and collimated simulator displays.

    PubMed

    Morahan, P; Meehan, J W; Patterson, J; Hughes, P K

    1998-09-01

    The purpose of this study was to investigate electrooculography (EOG) as a measurement of ocular vergence in both collimated and projected simulator environments. The task required participants to shift their gaze between a central fixation point and a target appearing at one of three eccentricities. EOG was effective in recording ocular vergence. The EOG results were similar between collimated and projected displays, except for differences in vergence changes during lateral movement of the eyes, and ocular excursions downward elicited a greater EOG response than the reverse upward movement. The computer-based technique of recording vergence was found to produce measurable traces from a majority of participants. The technique has potential for further development as a tool for measuring ocular vergence in virtual environments where methods that require the wearing of head-mounted apparatus to track ocular structures (e.g., the pupil), which cannot be worn at the same time as a flight or flight-simulator helmet, are unsuitable.

  20. Heater head for a Stirling engine

    SciTech Connect

    Darooka, D.K.

    1988-09-06

    A heater head is described for a compound Stirling engine modules, each including a displacer cylinder coaxially aligned with the displacer cylinder of the other of the engine modules, a displacer piston mounted for reciprocation in the displacer cylinder.

  1. Rebuilding Mount St. Helens

    USGS Publications Warehouse

    Schilling, Steve P.; Ramsey, David W.; Messerich, James A.; Thompson, Ren A.

    2006-01-01

    On May 18, 1980, Mount St. Helens, Washington exploded in a spectacular and devastating eruption that shocked the world. The eruption, one of the most powerful in the history of the United States, removed 2.7 cubic kilometers of rock from the volcano's edifice, the bulk of which had been constructed by nearly 4,000 years of lava-dome-building eruptions. In seconds, the mountain's summit elevation was lowered from 2,950 meters to 2,549 meters, leaving a north-facing, horseshoe-shaped crater over 2 kilometers wide. Following the 1980 eruption, Mount St. Helens remained active. A large lava dome began episodically extruding in the center of the volcano's empty crater. This dome-building eruption lasted until 1986 and added about 80 million cubic meters of rock to the volcano. During the two decades following the May 18, 1980 eruption, Crater Glacier formed tongues of ice around the east and west sides of the lava dome in the deeply shaded niche between the lava dome and the south crater wall. Long the most active volcano in the Cascade Range with a complex 300,000-year history, Mount St. Helens erupted again in the fall of 2004 as a new period of dome building began within the 1980 crater. Between October 2004 and February 2006, about 80 million cubic meters of dacite lava erupted immediately south of the 1980-86 lava dome. The erupting lava separated the glacier into two parts, first squeezing the east arm of the glacier against the east crater wall and then causing equally spectacular crevassing and broad uplift of the glacier's west arm. Vertical aerial photographs document dome growth and glacier deformation. These photographs enabled photogrammetric construction of a series of high-resolution digital elevation models (DEMs) showing changes from October 4, 2004 to February 9, 2006. From the DEMs, Geographic Information Systems (GIS) applications were used to estimate extruded volumes and growth rates of the new lava dome. The DEMs were also used to quantify dome

  2. MOUNT WASHINGTON WILDERNESS, OREGON.

    USGS Publications Warehouse

    Taylor, Edward M.; Causey, J. Douglas

    1984-01-01

    On the basis of a mineral survey, Mount Washington Wilderness, Oregon has little promise for the occurrence of metallic mineral or fossil fuel resources. Abundant cinder resources occur in the wilderness, but other large volume cinder deposits are available outside the wilderness and closer to markets. Analysis of the geothermal potential of the High Cascades province cannot be made without data on the subsurface thermal and hydrologic regimes which can only be provided by deep drill holes. Several deep holes could be drilled in areas outside the wildernesses of the High Cascades, from which extrapolations of the geothermal potential of the wildernesses could be made.

  3. 62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING WSW. THE GUN ITSELF EXTENDS BEYOND THE BRICK ARCHES OF THE MAIN SHOP FLOOR'S W WALL AND INTO THE W AISLE. THE LATHE'S CUTTING HEAD CAN BE SEEN AT THE RIGHT CENTER OF THE VIEW. (Ryan) - Watervliet Arsenal, Building No. 110, Hagner Road between Schull & Whittemore Roads, Watervliet, Albany County, NY

  4. An evaluation of flight path formats head-up and head-down

    NASA Technical Reports Server (NTRS)

    Sexton, George A.; Moody, Laura E.; Evans, Joanne; Williams, Kenneth E.

    1988-01-01

    Flight path primary flight display formats were incorporated on head-up and head-down electronic displays and integrated into an Advanced Concepts Flight Simulator. Objective and subjective data were collected while ten airline pilots evaluated the formats by flying an approach and landing task under various ceiling, visibility and wind conditions. Deviations from referenced/commanded airspeed, horizontal track, vertical track and touchdown point were smaller using the head-up display (HUD) format than the head-down display (HDD) format, but not significantly smaller. Subjectively, the pilots overwhelmingly preferred (1) flight path formats over attitude formats used in current aircraft, and (2) the head-up presentation over the head-down, primarily because it eliminated the head-down to head-up transition during low visibility landing approaches. This report describes the simulator, the flight displays, the format evaluation, and the results of the objective and subjective data.

  5. Head circumference

    MedlinePlus

    ... a child's head circumference Normal ranges for a child's sex and age (weeks, months), based on values that experts have obtained for normal growth rates of infants' and children's heads Measurement of the head circumference is an ...

  6. Head Lice

    MedlinePlus

    Head lice are parasitic wingless insects. They live on people's heads and feed on their blood. An adult louse ... Children ages 3-11 and their families get head lice most often. Personal hygiene has nothing to ...

  7. Surface mount component jig

    DOEpatents

    Kronberg, James W.

    1990-08-07

    A device for bending and trimming the pins of a dual-inline-package component and the like for surface mounting rather than through mounting to a circuit board comprises, in a first part, in pin cutter astride a holder having a recess for holding the component, a first spring therebetween, and, in a second part, two flat members pivotally interconnected by a hinge and urged to an upward peaked position from a downward peaked position by a second spring. As a downward force is applied to the pin cutter it urges the holder downward, assisted by the first spring and a pair of ridges riding on shoulders of the holder, to carry the component against the upward peaked flat members which guide the pins outwardly. As the holder continues downwardly, the flat members pivot to the downward peaked position bending the pins upwardly against the sides of the holder. When the downward movement is met with sufficient resistance, the ridges of the pin cutter ride over the holder's shoulders to continue downward to cut any excess length of pin.

  8. Voluntary presetting of the vestibular ocular reflex permits gaze stabilization despite perturbation of fast head movements

    NASA Technical Reports Server (NTRS)

    Zangemeister, Wolfgang H.

    1989-01-01

    Normal subjects are able to change voluntarily and continuously their head-eye latency together with their compensatory eye movement gain. A continuous spectrum of intent-latency modes of the subject's coordinated gaze through verbal feedback could be demonstrated. It was also demonstrated that the intent to counteract any perturbation of head-eye movement, i.e., the mental set, permitted the subjects to manipulate consciously their vestibular ocular reflex (VOR) gain. From the data, it is inferred that the VOR is always on. It may be, however, variably suppressed by higher cortical control. With appropriate training, head-mounted displays should permit an easy VOR presetting that leads to image stabilization, perhaps together with a decrease of possible misjudgements.

  9. Mount Vesuvius, Italy

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image of Mt. Vesuvius, Italy was acquired September 26, 2000. The full-size false-color image covers an area of 36 by 45 km. Vesuvius overlooks the city of Naples and the Bay of Naples in central Italy. (Popocatepetl and Mount Fuji are other volcanos surrounded by dense urban areas.) In 79 AD, Vesuvius erupted cataclysmically, burying all of the surrounding cites with up to 30 m of ash. The towns of Pompeii and Herculanaeum were rediscovered in the 18th century, and excavated in the 20th century. They provide a snapshot of Roman life from 2000 years ago: perfectly preserved are wooden objects, food items, and the casts of hundreds of victims. Vesuvius is intensively monitored for potential signs of unrest that could signal the beginning of another eruption. Image courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team

  10. Evaluating the Impact of Head Rotation Amplification on Virtual Reality Training Effectiveness

    SciTech Connect

    Ragan, Eric D; Bowman, Doug A; Scerbo, Siroberto; Bacim, Felipe

    2013-01-01

    Virtual reality (VR) systems have been proposed for use in numerous training scenarios, such as room clearing, which require the trainee to maintain spatial awareness. But many VR training systems lack a fully surrounding display, requiring trainees to use a combination of physical and virtual turns to view the environment, thus decreasing spatial awareness. One solution to this problem is to amplify head rotations, such that smaller physical turns are mapped to larger virtual turns, allowing trainees to view the surrounding environment with head movements alone. For example, in a multi-monitor system covering only a 90-degree field of regard, head rotations could be amplified four times to allow the user to see the entire 360-degree surrounding environment. This solution is attractive because it can be used with lower-cost VR systems and does not require virtual turning. However, the effects of amplified head rotations on spatial awareness and training transfer are not well understood. We hypothesized that small amounts of amplification might be tolerable, but that larger amplifications might cause trainees to become disoriented and to have decreased task performance and training transfer. In this paper, we will present our findings from an experiment designed to investigate these hypotheses. The experiment placed users in a virtual warehouse and asked them to move from room to room, counting objects placed around them in space. We varied the amount of amplification applied during these trials, and also varied the type of display used (head-mounted display or CAVE). We measured task performance and spatial awareness. We then assessed training transfer in an assessment environment with a fully surrounding display and no amplification. The results of this study will inform VR training system developers about the potential negative effects of using head rotation amplification and contribute to more effective VR training system design.

  11. Restocking the optical designers' toolbox for next-generation wearable displays (Presentation Recording)

    NASA Astrophysics Data System (ADS)

    Kress, Bernard C.

    2015-09-01

    Three years ago, industry and consumers learned that there was more to Head Mounted Displays (HMDs) than the long-lasting but steady market for defense or the market for gadget video player headsets: the first versions of Smart Glasses were introduced to the public. Since then, most major consumer electronics companies unveiled their own versions of Connected Glasses, Smart Glasses or Smart Eyewear, AR (Augmented Reality) and VR (Virtual Reality) headsets. This rush resulted in the build-up of a formidable zoo of optical technologies, each claiming to be best suited for the task on hand. Today, the question is not so much anymore "will the Smart Glass market happen?" but rather "which optical technologies will be best fitted for the various declinations of the existing wearable display market," one of the main declination being the Smart Glasses market.

  12. Flight experiment of pilot display for search-and-rescue helicopter

    NASA Astrophysics Data System (ADS)

    Funabiki, Kohei; Tsuda, Hiroka; Iijima, Tomoko; Nojima, Takuya; Tawada, Kazuho; Yoshida, Takashi

    2009-05-01

    JAXA (Japan Aerospace Exploration Agency), together with Shimadzu Corporation and NEC, has initiated a research project named SAVERH (Situation Awareness and Visual Enhancer for Rescue Helicopter) that aims at inventing method of presenting suitable pilot information to support helicopter search and rescue missions. As the initial stage of this research, a series of flight experiments was conducted to investigate the feasibility of operations enhanced by an E/SVS (Enhanced / Synthetic Vision System) and to clarify system issues. An integrated system comprising an HMD (Helmet Mounted Display) and a FLIR (Forward Looking Infrared) sensor were installed in a JAXA research helicopter, and Tunnel-in-the-Sky symbology and a Synthetic Terrain image combined with the FLIR image were presented on the HMD and/or on a Head Down Display (HDD). Through a total of 17 flights including night flights, the potential capability of the system was demonstrated while many issues for further investigation were identified.

  13. Updated defense display market assessment

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Hopper, Darrel G.

    1999-08-01

    This paper addresses the number, function and size of principal military displays and establishes a basis to determine the opportunities for technology insertion in the immediate future and into the next millennium. Principal military displays are defined as those occupying appreciable crewstation real-estate and/or those without which the platform could not carry out its intended mission. DoD 'office' applications are excluded from this study. The military displays market is specified by such parameters as active area and footprint size, and other characteristics such as luminance, gray scale, resolution, angle, color, video capability, and night vision imaging system compatibility. Funded, future acquisitions, planned and predicted crewstation modification kits, and form-fit upgrades are taken into account. This paper provides an overview of the DoD niche market, allowing both government and industry a necessary reference by which to meet DoD requirements for military displays in a timely and cost-effective manner. The aggregate DoD installed base for direct-view and large-area military displays is presently estimated to be in excess of 313,000. Miniature displays are those which must be magnified to be viewed, involve a significantly different manufacturing paradigm and are used in helmet mounted displays and thermal weapon sight applications. Some 114,000 miniature displays are presently included within future weapon system acquisition plans. For vendor production planning purposes it is noted that foreign military sales could substantially increase these quantities. The vanishing vendor syndrome (VVS) for older display technologies continues to be a growing, pervasive problem throughout DoD, which consequently must leverage the more modern, especially flat panel, display technologies being developed to replace older, especially cathode ray tube, technology for civil-commercial markets. Total DoD display needs (FPD, HMD) are some 427,000.

  14. Virtual acoustic displays

    NASA Technical Reports Server (NTRS)

    Wenzel, Elizabeth M.

    1991-01-01

    A 3D auditory display can potentially enhance information transfer by combining directional and iconic information in a quite naturalistic representation of dynamic objects in the interface. Another aspect of auditory spatial clues is that, in conjunction with other modalities, it can act as a potentiator of information in the display. For example, visual and auditory cues together can reinforce the information content of the display and provide a greater sense of presence or realism in a manner not readily achievable by either modality alone. This phenomenon will be particularly useful in telepresence applications, such as advanced teleconferencing environments, shared electronic workspaces, and monitoring telerobotic activities in remote or hazardous situations. Thus, the combination of direct spatial cues with good principles of iconic design could provide an extremely powerful and information-rich display which is also quite easy to use. An alternative approach, recently developed at ARC, generates externalized, 3D sound cues over headphones in realtime using digital signal processing. Here, the synthesis technique involves the digital generation of stimuli using Head-Related Transfer Functions (HRTF's) measured in the two ear-canals of individual subjects. Other similar approaches include an analog system developed by Loomis, et. al., (1990) and digital systems which make use of transforms derived from normative mannikins and simulations of room acoustics. Such an interface also requires the careful psychophysical evaluation of listener's ability to accurately localize the virtual or synthetic sound sources. From an applied standpoint, measurement of each potential listener's HRTF's may not be possible in practice. For experienced listeners, localization performance was only slightly degraded compared to a subject's inherent ability. Alternatively, even inexperienced listeners may be able to adapt to a particular set of HRTF's as long as they provide adequate

  15. Mount Zion Cemetery, 1975 Plot Plan Mount Zion Cemetery/ ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Mount Zion Cemetery, 1975 Plot Plan - Mount Zion Cemetery/ Female Union Band Cemetery, Bounded by 27th Street right-of-way N.W. (formerly Lyons Mill Road), Q Street N.W., & Mill Road N.W., Washington, District of Columbia, DC

  16. Virtual environment display for a 3D audio room simulation

    NASA Astrophysics Data System (ADS)

    Chapin, William L.; Foster, Scott

    1992-06-01

    Recent developments in virtual 3D audio and synthetic aural environments have produced a complex acoustical room simulation. The acoustical simulation models a room with walls, ceiling, and floor of selected sound reflecting/absorbing characteristics and unlimited independent localizable sound sources. This non-visual acoustic simulation, implemented with 4 audio ConvolvotronsTM by Crystal River Engineering and coupled to the listener with a Poihemus IsotrakTM, tracking the listener's head position and orientation, and stereo headphones returning binaural sound, is quite compelling to most listeners with eyes closed. This immersive effect should be reinforced when properly integrated into a full, multi-sensory virtual environment presentation. This paper discusses the design of an interactive, visual virtual environment, complementing the acoustic model and specified to: 1) allow the listener to freely move about the space, a room of manipulable size, shape, and audio character, while interactively relocating the sound sources; 2) reinforce the listener's feeling of telepresence into the acoustical environment with visual and proprioceptive sensations; 3) enhance the audio with the graphic and interactive components, rather than overwhelm or reduce it; and 4) serve as a research testbed and technology transfer demonstration. The hardware/software design of two demonstration systems, one installed and one portable, are discussed through the development of four iterative configurations. The installed system implements a head-coupled, wide-angle, stereo-optic tracker/viewer and multi-computer simulation control. The portable demonstration system implements a head-mounted wide-angle, stereo-optic display, separate head and pointer electro-magnetic position trackers, a heterogeneous parallel graphics processing system, and object oriented C++ program code.

  17. Surface Mounted Neutron Generators

    NASA Astrophysics Data System (ADS)

    Elizondo-Decanini, Juan M.

    2012-10-01

    A deuterium-tritium (DT) base reaction pulsed neutron generator packaged in a flat computer chip shape of 1.54 cm (0.600 in) wide by 3.175 cm (1.25 in) length and 0.3 cm (0.120 in) thick has been successfully demonstrated to produce 14 MeV neutrons at a rate of 10^9 neutrons per second. The neutron generator is based on a deuterium ion beam accelerated to impact a tritium loaded target. The accelerating voltage is in the 15 to 20 kV in a 3 mm (0.120 in) gap, the ion beam is shaped by using a lens design to produce a flat ion beam that conforms to the flat rectangular target. The ion source is a simple surface mounted deuterium filled titanium film with a fused gap that operates at a current-voltage design to release the deuterium during a pulse length of about 1 μs. We present the general description of the working prototypes, which we have labeled the ``NEUTRISTOR.''[4pt] Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration. Work funded by the LDRD office.

  18. Mount St. Helens Flyover

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image of Mt. St. Helens volcano in Washington State was acquired on August 8, 2000 and covers an area of 37 by 51 km. Mount Saint Helens, a volcano in the Cascade Range of southwestern Washington that had been dormant since 1857, began to show signs of renewed activity in early 1980. On 18 May 1980, it erupted with such violence that the top of the mountain was blown off, spewing a cloud of ash and gases that rose to an altitude of 19 kilometers. The blast killed about 60 people and destroyed all life in an area of some 180 square kilometers (some 70 square miles), while a much larger area was covered with ash and debris. It continues to spit forth ash and steam intermittently. As a result of the eruption, the mountain's elevation decreased from 2,950 meters to 2,549 meters. The simulated fly-over was produced by draping ASTER visible and near infrared image data over a digital topography model, created from ASTER's 3-D stereo bands. The color was computer enhanced to create a 'natural' color image, where the vegetation appears green. The topography has been exaggerated 2 times to enhance the appearance of the relief. Landsat7 aquired an image of Mt. St. Helens on August 22, 1999. Image and animation courtesy NASA/GSFC/MITI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.

  19. Mouse Cochlear Whole Mount Immunofluorescence

    PubMed Central

    Akil, Omar; Lustig, Lawrence R.

    2016-01-01

    This protocol comprises the entire process of immunofluorescence staining on mouse cochlea whole mount, starting from tissue preparation to the mounting of the tissue. This technique provides “three-dimensional” views of the stained components in order to determine the localization of a protein of interest in the tissue in its natural state and environment. PMID:27547786

  20. Augmenting digital displays with computation

    NASA Astrophysics Data System (ADS)

    Liu, Jing

    As we inevitably step deeper and deeper into a world connected via the Internet, more and more information will be exchanged digitally. Displays are the interface between digital information and each individual. Naturally, one fundamental goal of displays is to reproduce information as realistically as possible since humans still care a lot about what happens in the real world. Human eyes are the receiving end of such information exchange; therefore it is impossible to study displays without studying the human visual system. In fact, the design of displays is rather closely coupled with what human eyes are capable of perceiving. For example, we are less interested in building displays that emit light in the invisible spectrum. This dissertation explores how we can augment displays with computation, which takes both display hardware and the human visual system into consideration. Four novel projects on display technologies are included in this dissertation: First, we propose a software-based approach to driving multiview autostereoscopic displays. Our display algorithm can dynamically assign views to hardware display zones based on multiple observers' current head positions, substantially reducing crosstalk and stereo inversion. Second, we present a dense projector array that creates a seamless 3D viewing experience for multiple viewers. We smoothly interpolate the set of viewer heights and distances on a per-vertex basis across the arrays field of view, reducing image distortion, crosstalk, and artifacts from tracking errors. Third, we propose a method for high dynamic range display calibration that takes into account the variation of the chrominance error over luminance. We propose a data structure for enabling efficient representation and querying of the calibration function, which also allows user-guided balancing between memory consumption and the amount of computation. Fourth, we present user studies that demonstrate that the ˜ 60 Hz critical flicker fusion

  1. LED display for solo aircraft instrument navigation

    NASA Technical Reports Server (NTRS)

    Crouch, R. K.; Kelly, W. L., VI; Lina, L. J.; Meredith, B. D.

    1979-01-01

    Solo pilot's task is made easier through convenient display of landing and navigation data. Use of display shows promise as more efficient means of presenting sequential instructions and data, such as course heading, altitude, and radio frequency, to minimize pilot's workload during solo instrument flight.

  2. The Second Generation High Speed Rotor Head Mounted Instrumentation System

    NASA Technical Reports Server (NTRS)

    Lewis, John; Reynolds, R. S. (Technical Monitor)

    1997-01-01

    NASA Ames Research Center has been investigating the air pressure flow of a rotor blade on a UH-60 Black Hawk helicopter in-flight. This paper will address the changes and improvements due to additional restrictions and requirements for the instrumentation system. The second generation instrumentation system was substantially larger and this allowed greatly improved accessibility to the components for ease of maintenance as well as improved gain and offset adjustment capabilities and better filtering.

  3. Mount Rainier National Park

    USGS Publications Warehouse

    Hoffman, Robert; Woodward, Andrea; Haggerty, Patricia K.; Jenkins, Kurt J.; Griffin, Paul C.; Adams, Michael J.; Hagar, Joan; Cummings, Tonnie; Duriscoe, Dan; Kopper, Karen; Riedel, Jon; Samora, Barbara; Marin, Lelaina; Mauger, Guillaume S.; Bumbaco, Karen; Littell, Jeremy S.

    2014-01-01

    Natural Resource Condition Assessments (NRCAs) evaluate current conditions for a subset of natural resources and resource indicators in national parks. NRCAs also report on trends in resource condition (when possible), identify critical data gaps, and characterize a general level of confidence for study findings. The resources and indicators emphasized in a given project depend on the park’s resource setting, status of resource stewardship planning and science in identifying high-priority indicators, and availability of data and expertise to assess current conditions for a variety of potential study resources and indicators. Although the primary objective of NRCAs is to report on current conditions relative to logical forms of reference conditions and values, NRCAs also report on trends, when appropriate (i.e., when the underlying data and methods support such reporting), as well as influences on resource conditions. These influences may include past activities or conditions that provide a helpful context for understanding current conditions and present-day threats and stressors that are best interpreted at park, watershed, or landscape scales (though NRCAs do not report on condition status for land areas and natural resources beyond park boundaries). Intensive cause-andeffect analyses of threats and stressors, and development of detailed treatment options, are outside the scope of NRCAs. It is also important to note that NRCAs do not address resources that lack sufficient data for assessment. For Mount Rainier National Park, this includes most invertebrate species and many other animal species that are subject to significant stressors from climate change and other anthropogenic sources such as air pollutants and recreational use. In addition, we did not include an analysis of the physical hydrology associated with streams (such as riverine landforms, erosion and aggradation which is significant in MORA streams), due to a loss of staff expertise from the USGS

  4. Mount St. Helens

    NASA Technical Reports Server (NTRS)

    2005-01-01

    This Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) image of Mount St. Helens was captured one week after the March 8, 2005, ash and steam eruption, the latest activity since the volcano's reawakening in September 2004. The new lava dome in the southeast part of the crater is clearly visible, highlighted by red areas where ASTER's infrared channels detected hot spots from incandescent lava. The new lava dome is 155 meters (500 feet) higher than the old lava dome, and still growing.

    With its 14 spectral bands from the visible to the thermal infrared wavelength region, and its high spatial resolution of 15 to 90 meters (about 50 to 300 feet), ASTER images Earth to map and monitor the changing surface of our planet.

    ASTER is one of five Earth-observing instruments launched December 18, 1999, on NASA's Terra satellite. The instrument was built by Japan's Ministry of Economy, Trade and Industry. A joint U.S./Japan science team is responsible for validation and calibration of the instrument and the data products.

    The broad spectral coverage and high spectral resolution of ASTER provides scientists in numerous disciplines with critical information for surface mapping, and monitoring of dynamic conditions and temporal change. Example applications are: monitoring glacial advances and retreats; monitoring potentially active volcanoes; identifying crop stress; determining cloud morphology and physical properties; wetlands evaluation; thermal pollution monitoring; coral reef degradation; surface temperature mapping of soils and geology; and measuring surface heat balance.

    The U.S. science team is located at NASA's Jet Propulsion Laboratory, Pasadena, Calif. The Terra mission is part of NASA's Science Mission Directorate.

    Size: 21.9 by 24.4 kilometers (13.6 by 15.1 miles) Location: 46.2 degrees North latitude, 122.2 degrees West longitude Orientation: North at top Image Data: ASTER bands 8, 3, and 1 Original Data Resolution

  5. 14. AERIAL VIEW OF ENGINE DISPLAY INSIDE PASSENGER CAR SHOP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    14. AERIAL VIEW OF ENGINE DISPLAY INSIDE PASSENGER CAR SHOP (NOW A TRANSPORTATION MUSEUM) - Baltimore & Ohio Railroad, Mount Clare Passenger Car Shop, Southwest corner of Pratt & Poppleton Streets, Baltimore, Independent City, MD

  6. Head Injuries

    MedlinePlus

    ... injuries internal head injuries, which may involve the skull, the blood vessels within the skull, or the brain Fortunately, most childhood falls or ... knock the brain into the side of the skull or tear blood vessels. Some internal head injuries ...

  7. Head Lice

    MedlinePlus

    ... or prescription products. Over-the-counter shampoos and lotions containing pyrethrin (one brand name: Rid) or permethrin ( ... commonly used to treat head lice. Shampoos and lotions that kill head lice contain pesticides and other ...

  8. Head MRI

    MedlinePlus

    ... the head; MRI - cranial; NMR - cranial; Cranial MRI; Brain MRI; MRI - brain; MRI - head ... the test, tell your provider if you have: Brain aneurysm clips An artificial heart valves Heart defibrillator ...

  9. Part mounting revisited

    SciTech Connect

    Hannah, P.R.; Garcia, F.P.; Stewart, D.D.

    1992-01-01

    Having been involved with single point diamond turning since the 1960's; I share with others of my age, a unique perspective of the craft. I am amazed at how the fundamentals seem to be forgotten or misplaced, and need to be re emphasized and re learned. Each new precision machine operator not only needs to re learn (many times the hard way), these fundamentals, but seems to inherit all the folklore; good and bad, from his predecessor. Let me explain. I spend some of my time as a consultant to the shops' division at the Los Alamos National Laboratory, at which there are five precision turning machines divided between two buildings. The main shop area houses an old friction way (hydrodynamic) turning Machine. The base of this turning machine is made from the base of an old Moore measuring machine. The air bearing spindle, a Red Head'' was made by the Heald Machine Tool Co. With the addition of an Allen-Bradley Numerical control system, this machine has become a work horse, used primarily to make smooth flat surfaces in the fly-cutting mode. Recently, I became involved in the evaluation and repair of the machine as it no longer produced smooth surfaces. Smooth surfaces are not the point of this narrative, accurate geometry however is.

  10. Part mounting revisited

    SciTech Connect

    Hannah, P.R.; Garcia, F.P.; Stewart, D.D.

    1992-10-01

    Having been involved with single point diamond turning since the 1960`s; I share with others of my age, a unique perspective of the craft. I am amazed at how the fundamentals seem to be forgotten or misplaced, and need to be re emphasized and re learned. Each new precision machine operator not only needs to re learn (many times the hard way), these fundamentals, but seems to inherit all the folklore; good and bad, from his predecessor. Let me explain. I spend some of my time as a consultant to the shops` division at the Los Alamos National Laboratory, at which there are five precision turning machines divided between two buildings. The main shop area houses an old friction way (hydrodynamic) turning Machine. The base of this turning machine is made from the base of an old Moore measuring machine. The air bearing spindle, a ``Red Head`` was made by the Heald Machine Tool Co. With the addition of an Allen-Bradley Numerical control system, this machine has become a work horse, used primarily to make smooth flat surfaces in the fly-cutting mode. Recently, I became involved in the evaluation and repair of the machine as it no longer produced smooth surfaces. Smooth surfaces are not the point of this narrative, accurate geometry however is.

  11. Detector Mount Design for IGRINS

    NASA Astrophysics Data System (ADS)

    Oh, Jae Sok; Park, Chan; Cha, Sang-Mok; Yuk, In-Soo; Park, Kwijong; Kim, Kang-Min; Chun, Moo-Young; Ko, Kyeongyeon; Oh, Heeyoung; Jeong, Ueejeong; Nah, Jakyoung; Lee, Hanshin; Jaffe, Daniel T.

    2014-06-01

    The Immersion Grating Infrared Spectrometer (IGRINS) is a near-infrared wide-band high-resolution spectrograph jointly developed by the Korea Astronomy and Space Science Institute and the University of Texas at Austin. IGRINS employs three HAWAII-2RG Focal Plane Array (H2RG FPA) detectors. We present the design and fabrication of the detector mount for the H2RG detector. The detector mount consists of a detector housing, an ASIC housing, a Field Flattener Lens (FFL) mount, and a support base frame. The detector and the ASIC housing should be kept at 65 K and the support base frame at 130 K. Therefore they are thermally isolated by the support made of GFRP material. The detector mount is designed so that it has features of fine adjusting the position of the detector surface in the optical axis and of fine adjusting yaw and pitch angles in order to utilize as an optical system alignment compensator. We optimized the structural stability and thermal characteristics of the mount design using computer-aided 3D modeling and finite element analysis. Based on the structural and thermal analysis, the designed detector mount meets an optical stability tolerance and system thermal requirements. Actual detector mount fabricated based on the design has been installed into the IGRINS cryostat and successfully passed a vacuum test and a cold test.

  12. SXI prototype mirror mount

    NASA Technical Reports Server (NTRS)

    1995-01-01

    The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve

  13. SXI prototype mirror mount

    NASA Astrophysics Data System (ADS)

    1995-04-01

    The purpose of this contract was to provide optomechanical engineering and fabrication support to the Solar X-ray Imager (SXI) program in the areas of mirror, optical bench and camera assemblies of the telescope. The Center for Applied Optics (CAO) worked closely with the Optics and S&E technical staff of MSFC to develop and investigate the most viable and economical options for the design and fabrication of a number of parts for the various telescope assemblies. All the tasks under this delivery order have been successfully completed within budget and schedule. A number of development hardware parts have been designed and fabricated jointly by MSFC and UAH for the engineering model of SXI. The major parts include a nickel electroformed mirror and a mirror mount, plating and coating of the ceramic spacers, and gold plating of the contact rings and fingers for the camera assembly. An aluminum model of the high accuracy sun sensor (HASS) was also designed and fabricated. A number of fiber optic tapers for the camera assembly were also coated with indium tin oxide and phosphor for testing and evaluation by MSFC. A large number of the SXI optical bench parts were also redesigned and simplified for a prototype telescope. These parts include the forward and rear support flanges, front aperture plate, the graphite epoxy optical bench and a test fixture for the prototype telescope. More than fifty (50) drawings were generated for various components of the prototype telescope. Some of these parts were subsequently fabricated at UAH machine shop or at MSFC or by the outside contractors. UAH also provide technical support to MSFC staff for a number of preliminary and critical design reviews. These design reviews included PDR and CDR for the mirror assembly by United Technologies Optical Systems (UTOS), and the program quarterly reviews, and SXI PDR and CDR. UAH staff also regularly attended the monthly status reviews, and made a significant number of suggestions to improve

  14. Retired NASA F-18 being mounted on pedestal mount at Lancaster California Municipal Baseball Stadium

    NASA Technical Reports Server (NTRS)

    1997-01-01

    While workers on the ground steady the craft with guy ropes, workers atop a high-lift truck align the mounting plates as an F/A-18 Hornet airplane formerly flown by NASA's Dryden Flight Research Center is mounted on a 28-foot-tall pedestal in front of the municipal baseball stadium in the city of Lancaster, California. The aircraft was loaned to the city for pulbic display after its recent retirement by Dryden, which is located at nearby Edwards, California. The blue-and-white twin-jet aircraft was flown as a safety chase and support aircraft by NASA Dryden for about nine years before being retired. Known as 'The Hangar,' the stadium is the home field of the Lancaster Jethawks, a Class-A farm team of the Seattle Mariners.

  15. Cockpit display requirements and specifications

    NASA Astrophysics Data System (ADS)

    Hopper, Darrel G.

    1993-12-01

    Flight instrument design has begun to include a new electronic technology for the display head: active matrix liquid crystal display (AMLCD). This is a significant design transition and applies across the board to complete cockpit modernization programs, individual instrument replacement projects, and new systems. AMLCD-based instruments are expected to have a substantially higher mean time between failure compared to both electromechanical and CRT- based instruments. Thus, the new technology will pay for itself. Furthermore, AMLCDs are truly sunlight-readable whereas CRT displays are not; it is mission critical that a pilot be able to see an instrument with the sun shining directly in the eye or onto the display. AMLCDs can also provide larger display areas enabling formats which increase situational awareness. As this is a new technology for the military, an industrial base for militarized AMLCDs must be created based on present research capabilities. The requirements for AMLCDs in DOD programs have been analyzed. Projects to build infrastructure and capacity are described. Applications include not only cockpits, but also digital map/GPS integrated displays for tank commanders and field laptop computers. We have the opportunity with this new technology to establish a common critical item product function specification for sunlight-readable, color and grayscale capable, flat panel displays for military applications. the Wright Laboratory is leading the development of such functional specification for U.S. military aircraft.

  16. Solar panel parallel mounting configuration

    NASA Technical Reports Server (NTRS)

    Mutschler, Jr., Edward Charles (Inventor)

    1998-01-01

    A spacecraft includes a plurality of solar panels interconnected with a power coupler and an electrically operated device to provide power to the device when the solar cells are insolated. The solar panels are subject to bending distortion when entering or leaving eclipse. Spacecraft attitude disturbances are reduced by mounting each of the solar panels to an elongated boom made from a material with a low coefficient of thermal expansion, so that the bending of one panel is not communicated to the next. The boom may be insulated to reduce its bending during changes in insolation. A particularly advantageous embodiment mounts each panel to the boom with a single mounting, which may be a hinge. The single mounting prevents transfer of bending moments from the panel to the boom.

  17. Kinematic high bandwidth mirror mount

    DOEpatents

    Kuklo, T.C.

    1995-03-21

    An adjustable mirror mount system for a mirror is disclosed comprising a mirror support having a planar surface thereon, a mirror frame containing a mirror and having a planar surface behind the mirror facing the planar surface of the mirror support and parallel to the reflecting surface of the mirror and mounted pivotally to the mirror support at a point central to the frame, a first adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along one axis lying in the plane of the planar surface of the mirror frame; and a second adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along a second axis lying in the plane of the planar surface of the mirror frame and perpendicular to the first axis. 7 figures.

  18. Kinematic high bandwidth mirror mount

    DOEpatents

    Kuklo, Thomas C.

    1995-01-01

    An adjustable mirror mount system for a mirror is disclosed comprising a mirror support having a planar surface thereon, a mirror frame containing a mirror and having a planar surface behind the mirror facing the planar surface of the mirror support and parallel to the reflecting surface of the mirror and mounted pivotally to the mirror support at a point central to the frame, a first adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along one axis lying in the plane of the planar surface of the mirror frame; and a second adjustment means between the mirror support and the mirror frame spaced from the central pivot mount for adjusting the movement of the mirror along a second axis lying in the plane of the planar surface of the mirror frame and perpendicular to the first axis.

  19. Dry tilt network at Mount Rainier, Washington

    USGS Publications Warehouse

    Dzurisin, Daniel; Johnson, Daniel J.; Symonds, R.B.

    1984-01-01

    In addition to its primary responsibility of monitoring active Mount St. Helens, the David A. Johnston Cascades Volcano Observatory (CVO) has been charged with obtaining baseline geodetic and geochemical information at each of the other potentially active Cascade volcanoes. Dry tilt and/or trilateration networks were established during 1975-82 at Mount Baker, Mount St. Helens, Mount Hood, Mount Shasta, Lassen Peak, Crater Lake, and Long Valley caldera; coverage was extended during September 1982 to include Mount Rainier.

  20. Comparing the effectiveness of different displays in enhancing illusions of self-movement (vection)

    PubMed Central

    Riecke, Bernhard E.; Jordan, Jacqueline D.

    2015-01-01

    Illusions of self-movement (vection) can be used in virtual reality (VR) and other applications to give users the embodied sensation that they are moving when physical movement is unfeasible or too costly. Whereas a large body of vection literature studied how various parameters of the presented visual stimulus affect vection, little is known how different display types might affect vection. As a step toward addressing this gap, we conducted three experiments to compare vection and usability parameters between commonly used VR displays, ranging from stereoscopic projection and 3D TV to high-end head-mounted display (HMD, NVIS SX111) and recent low-cost HMD (Oculus Rift). The last experiment also compared these two HMDs in their native full field of view (FOV) and a reduced, matched FOV of 72° × 45°. Participants moved along linear and curvilinear paths in the virtual environment, reported vection onset time, and rated vection intensity at the end of each trial. In addition, user ratings on immersion, motion sickness, vection, and overall preference were recorded retrospectively and compared between displays. Unexpectedly, there were no significant effects of display on vection measures. Reducing the FOV for the HMDs (from full to 72° × 45°) decreased vection onset latencies, but did not affect vection intensity. As predicted, curvilinear paths yielded earlier and more intense vection. Although vection has often been proposed to predict or even cause motion sickness, we observed no correlation for any of the displays studied. In conclusion, perceived self-motion and other user experience measures proved surprisingly tolerant toward changes in display type as long as the FOV was roughly matched. This suggests that display choice for vection research and VR applications can be largely based on other considerations as long as the provided FOV is sufficiently large. PMID:26082735

  1. Computerized system for translating a torch head

    NASA Technical Reports Server (NTRS)

    Wall, W. A., Jr.; Ives, R. E.; Bruce, M. M., Jr.; Pryor, P. P., Jr.; Gard, L. H. (Inventor)

    1978-01-01

    The system provides a constant travel speed along a contoured workpiece. It has a driven skate characterized by an elongated bed, with a pair of independently pivoted trucks connected to the bed for support. The trucks are mounted on a contoured track of arbitrary configuration in a mutually spaced relation. An axially extensible torch head manipulator arm is mounted on the bed of the carriage and projects perpendicular from the midportion. The torch head is mounted at its distal end. A real-time computerized control drive subsystem is used to advance the skate along the track of a variable rate for maintaining a constant speed for the torch head tip, and to position the torch axis relative to a preset angle to the workpiece.

  2. Retired NASA F-18 being mounted on pedestal mount at Lancaster California Municipal Baseball Stadium

    NASA Technical Reports Server (NTRS)

    1997-01-01

    An F/A-18 Hornet aircraft formerly flown by NASA's Dryden Flight Research Center, Edwards, California, is sandwiched between two groups of workers as they mount it atop a pedestal at the municipal baseball stadium in the city of Lancaster, California. NASA Dryden had flown the blue-and-white twin-jet as a safety chase and support aircraft for about nine years prior to its recent retirement. The aircraft is now in loan to the city for public display. Known as 'The Hangar,' the stadium is the home field of the Lancaster Jethawks, a Class-A farm team of the Seattle Mariners.

  3. Retired NASA F-18 being mounted on pedestal mount at Lancaster California Municipal Baseball Stadium

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Workers carefully align a mounting bracket attached to an F/A-18 Hornet aircraft with the top of a pedestal in front of the municipal baseball stadium in the city of Lancaster, California. The Blue-and-white twin-jet aircraft, formerly flown as a safety chase and support aircraft by NASA's Dryden Flight Research Center, Edwards, California, was loaned to the city for display following its recent retirement. Known as 'The Hangar,' the stadium is the home field of the Lancaster Jethawks, a Class-A farm team of the Seattle Mariners.

  4. Virtual sine arm kinematic mount system

    SciTech Connect

    Xu, Z.; Randall, K.J.

    1997-09-01

    A novel kinematic mount system for a vertical focusing mirror of the soft x-ray spectroscopy beamline at the Advanced Photon Source is described. The system contains three points in a horizontal plane. Each point consists of two horizontal linear precision stages, a spherical ball bearing, and a vertical precision stage. The horizontal linear stages are aligned orthogonally and are conjoined by a spherical ball bearing, supported by the vertical linear stage at each point. The position of each confined horizontal stage is controlled by a motorized micrometer head by spring-loading the flat tip of the micrometer head onto a tooling ball fixing on the carriage of the stage. A virtual sine arm is formed by tilting the upstream horizontal stage down and the two downstream horizontal stages up by a small angle. The fine pitch motion is achieved by adjusting the upstream stage. This supporting structure is extremely steady due to a relatively large span across the supporting points and yields extremely high resolution on the pitch motion. With a one degree tilt and a microstepping motor, the authors achieved a 0.4 nanoradian resolution on the mirror pitch motion.

  5. Examiner's finger-mounted fetal tissue oximetry

    NASA Astrophysics Data System (ADS)

    Kanayama, Naohiro; Niwayama, Masatsugu

    2014-06-01

    The best way to assess fetal condition is to observe the oxygen status of the fetus (as well as to assess the condition of infants, children, and adults). Previously, several fetal oximeters have been developed; however, no instrument has been utilized in clinical practice because of the low-capturing rate of the fetal oxygen saturation. To overcome the problem, we developed a doctor's finger-mounted fetal tissue oximeter, whose sensor volume is one hundredth of the conventional one. Additionally, we prepared transparent gloves. The calculation algorithm of the hemoglobin concentration was derived from the light propagation analysis based on the transport theory. We measured neonatal and fetal oxygen saturation (StO2) with the new tissue oximeter. Neonatal StO was measured at any position of the head regardless of amount of hair. Neonatal StO was found to be around 77%. Fetal StO was detected in every position of the fetal head during labor regardless of the presence of labor pain. Fetal StO without labor pain was around 70% in the first stage of labor and around 60% in the second stage of labor. We concluded that our new concept of fetal tissue oximetry would be useful for detecting fetal StO in any condition of the fetus.

  6. Solar panel truss mounting systems and methods

    DOEpatents

    Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

    2015-10-20

    An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

  7. Solar panel truss mounting systems and methods

    DOEpatents

    Al-Haddad, Tristan Farris; Cavieres, Andres; Gentry, Russell; Goodman, Joseph; Nolan, Wade; Pitelka, Taylor; Rahimzadeh, Keyan; Brooks, Bradley; Lohr, Joshua; Crooks, Ryan; Porges, Jamie; Rubin, Daniel

    2016-06-28

    An exemplary embodiment of the present invention provides a solar panel truss mounting system comprising a base and a truss assembly coupled to the base. The truss assembly comprises a first panel rail mount, second panel rail mount parallel to the first panel rail mount, base rail mount parallel to the first and second panel rail mounts, and a plurality of support members. A first portion of the plurality of support members extends between the first and second panel rail mounts. A second portion of the plurality of support members extends between the first panel rail mount and the base rail mount. A third portion of the plurality of support members extends between the second panel rail mount and the base rail mount. The system can further comprise a plurality of connectors for coupling a plurality of photovoltaic solar panels to the truss assembly.

  8. Ice Volumes on Cascade Volcanoes: Mount Rainier, Mount Hood, Three Sisters, and Mount Shasta

    USGS Publications Warehouse

    Driedger, Carolyn L.; Kennard, Paul M.

    1986-01-01

    During the eruptions of Mount St. Helens the occurrence of floods and mudflows made apparent the need for predictive water-hazard analysis of other Cascade volcanoes. A basic requirement for such analysis is information about the volumes and distributions of snow and ice on other volcanoes. A radar unit contained in a backpack was used to make point measurements of ice thickness on major glaciers of Mount Rainier, Wash.; Mount Hood, Oreg.; the Three Sisters, Oreg.; and Mount Shasta, Calif. The measurements were corrected for slope and were used to develop subglacial contour maps from which glacier volumes were measured. These values were used to develop estimation methods for finding volumes of unmeasured glaciers. These methods require a knowledge of glacier slope, altitude, and area and require an estimation of basal shear stress, each estimate derived by using topographic maps updated by aerial photographs. The estimation methods were found to be accurate within ?20 percent on measured glaciers and to be within ?25 percent when applied to unmeasured glaciers on the Cascade volcanoes. The estimation methods may be applicable to other temperate glaciers in similar climatic settings. Areas and volumes of snow and ice are as follows: Mount Rainier, 991 million ft2, 156 billion ft3; Mount Hood, 145 million ft2, 12 billion ft3; Three Sisters, 89 million ft2, 6 billion ft3; and Mount Shasta, 74 million ft2, 5 billion ft3. The distribution of ice and firn patches within 58 glacierized basins on volcanoes is mapped and listed by altitude and by watershed to facilitate water-hazard analysis.

  9. VIBRATION DAMPING AND SHOCK MOUNT

    DOEpatents

    Stevens, D.J.; Forman, G.W.

    1963-12-10

    A shock absorbing mount in which vibrations are damped by an interference fit between relatively movable parts of the mount is described. A pair of generally cup-shaped parts or members have skirt portions disposed in an oppositely facing nesting relationship with the skirt of one member frictionally engaging the skirt of the other. The outermost skirt may be slotted to provide spring-like segments which embrace the inner skirt for effecting the interference fit. Belleville washers between the members provide yieldable support for a load carried by the mount. When a resonant frequency of vibration forces acting upon the moumt attains a certain level the kinetic energy of these forces is absorbed by sliding friction between the parts. (AEC)

  10. An improved instrument mounting arm.

    PubMed

    Gendeh, B S; Khalid, B A; Alberti, P W

    2001-02-01

    Although some form of commercial instrument mounting arm is available, a paucity of information in the literature may cause problems in selecting the most appropriate model for an ENT department wishing to trial their invention for use in the clinic or operating theatre. The instrument mounting arm described here is based on existing designs used by hobbyists and model makers for many years but the main benefit of this innovation is its multi-purpose use in the operating theatre and cost effectiveness since it is made of aluminum alloy. It is compact, stable and easily adjustable and can incorporate an endoscope holder or an operating end piece to mount various ENT instruments that offers considerable advantages to the unassisted operator.

  11. Off-axis photopolymer holographic elements for large-field-of-view visor-projected displays

    NASA Astrophysics Data System (ADS)

    Sergeant, Shirley A.; Hurst, Andrew E.

    1995-03-01

    A number of helmet mounted displays have been designed in recent years. The majority of these designs have been dismissed on the grounds of safety when considering the optical configuration. The principle of the design discussed in this paper is that of a display projected using the visor, where it acts not only as the display visor but also provides windblast, laser, and nuclear flash, protection. The display is projected by means of a holographic combining element on the visor. This paper addresses the design and manufacture of the holographic components employed, discussing the use of DuPont photopolymer material for this application. Off-axis holograms configured around the geometry of the head/helmet, give a wide field of view, with good eye relief. Well defined reflective and transmissive properties of the hologram are required to give full system compatibility. The resultant system does not compromise the safety of the user, whilst maintaining a fully integrated man/machine interface, i.e. low mass, and manageable center of gravity.

  12. The glass dome: low-occlusion obstacle symbols for conformal displays

    NASA Astrophysics Data System (ADS)

    Peinecke, Niklas; Chignola, Alvaro; Schmid, Daniela; Friedl, Hartmut

    2016-05-01

    Contemporary helmet mounted displays integrate high-resolution display units together with precise head-tracking solutions. This combination offers the opportunity to show symbols in a conformal way. Conformality here means that a hazard symbol is linked to the outside scenery. Thus, a pilot intuitively understands the connection between the symbol and its corresponding terrain feature, even if the feature is not fully visible due to degraded visual conditions. To accomplish this purpose the symbol has to be sufficiently noticeable in terms of size and brightness. However, this gives rise to the danger that parts of the outside scenery are occluded by the symbol. Furthermore, symbols should not clutter the display, in order not to distract the pilot. We present a solution framework of highlighting obstacles by symbols that balance low occlusion against noticeability. Our concept allows including different representations for individual classes of obstacles in a unified way. We detail the implementation of the display symbols. Finally, we present results of a first acceptance test with pilots.

  13. Diffractive optics for compact flat panel displays. Final report

    SciTech Connect

    Sweeney, D.; DeLong, K.

    1997-04-29

    Three years ago LLNL developed a practical method to dramatically reduce the chromatic aberration in single element diffractive imaging lenses. High efficiency, achromatic imaging lenses have been fabricated for human vision correction. This LDRD supported research in applying our new methods to develop a unique, diffraction-based optical interface with solid state, microelectronic imaging devices. Advances in microelectronics have led to smaller, more efficient components for optical systems. There have, however, been no equivalent advances in the imaging optics associated with these devices. The goal of this project was to replace the bulky, refractive optics in typical head-mounted displays with micro-thin diffractive optics to directly image flat-panel displays into the eye. To visualize the system think of the lenses of someone`s eyeglasses becoming flat-panel displays. To realize this embodiment, we needed to solve the problems of large chromatic aberrations and low efficiency that are associated with diffraction. We have developed a graceful tradeoff between chromatic aberrations and the diffractive optic thickness. It turns out that by doubling the thickness of a micro-thin diffractive lens we obtain nearly a two-times improvement in chromatic performance. Since the human eye will tolerate one diopter of chromatic aberration, we are able to achieve an achromatic image with a diffractive lens that is only 20 microns thick, versus 3 mm thickness for the comparable refractive lens. Molds for the diffractive lenses are diamond turned with sub-micron accuracy; the final lenses are cast from these molds using various polymers. We thus retain both the micro- thin nature of the diffractive optics and the achromatic image quality of refractive optics. During the first year of funding we successfully extended our earlier technology from 1 cm diameter optics required for vision applications up to the 5 cm diameter optics required for this application. 3 refs., 6 figs.

  14. Head perturbations during walking while viewing a head-fixed target

    NASA Technical Reports Server (NTRS)

    Das, Vallabh E.; Zivotofsky, Ari Z.; Discenna, Alfred O.; Leigh, R. John

    1995-01-01

    Inexpensive, head-fixed computer displays are now available that subjects can wear during locomotion. Our hypothesis is that viewing a head-fixed visual display will change the character- istics of rotational head perturbations during natural walking. Using a 3-axis angular rate sensor, we measured head rotations during natural or treadmill walking, in 10 normal subjects and 2 patients with deficient vestibular function, as they attempted to view (1) a stationary target at optical infinity; and (2) a target at a distance of 20 cm rigidly attached to the head. Normal subjects and patients showed no significant change in the predominant frequency of head rotations in any plane (ranging 0.7-5.7 Hz) during the two different viewing tasks. Mean peak head velocities also showed no difference during the two viewing conditions except in the yaw plane, in which values were greater while viewing the near target. Predominant frequencies of head rotations were similar in the pitch plane during natural or treadmill walking; however, peak velocities of pitch head rotations were substantially greater during natural walking. One vestibular patient showed modest increases of head velocity during natural walking compared with normal subjects. Rotational head perturbations that occur during natural walking are largely unaffected when subjects view a head-fixed target. There is need to study how such perturbations, which induce vestibular eye movements, affect vision of head-fixed displays.

  15. Color Breakup In Sequentially-Scanned LC Displays

    NASA Technical Reports Server (NTRS)

    Arend, L.; Lubin, J.; Gille, J.; Larimer, J.; Statler, Irving C. (Technical Monitor)

    1994-01-01

    In sequentially-scanned liquid-crystal displays the chromatic components of color pixels are distributed in time. For such displays eye, head, display, and image-object movements can cause the individual color elements to be visible. We analyze conditions (scan designs, types of eye movement) likely to produce color breakup.

  16. Mount St. Mary's College. Exemplars.

    ERIC Educational Resources Information Center

    Iannozzi, Maria

    This report describes the efforts of Mount St. Mary's College (California) to extend the benefits of a strong, traditional baccalaureate program to an underserved population of women in an urban region, including substantial numbers of minority and first-generation college students. To help realize its service mission and increase access to…

  17. Cryogenically cooled detector pin mount

    SciTech Connect

    Hunt, Jr., William E; Chrisp, Michael P

    2014-06-03

    A focal plane assembly facilitates a molybdenum base plate being mounted to another plate made from aluminum. The molybdenum pin is an interference fit (press fit) in the aluminum base plate. An annular cut out area in the base plate forms two annular flexures.

  18. 36 Views of Mount Rainier

    ERIC Educational Resources Information Center

    Fortune, Tracy

    2011-01-01

    Look for ways to take students on virtual journeys to faraway places, and then connect the experience to something they can relate to on a more personal level. In this article, the author describes a block-printing unit inspired by Japanese printmaker, Katsushika Hokusai (1760-1849), and his series of art prints, "Thirty-six Views of Mount Fuji."…

  19. Mount Rainier active cascade volcano

    NASA Technical Reports Server (NTRS)

    1994-01-01

    Mount Rainier is one of about two dozen active or recently active volcanoes in the Cascade Range, an arc of volcanoes in the northwestern United States and Canada. The volcano is located about 35 kilometers southeast of the Seattle-Tacoma metropolitan area, which has a population of more than 2.5 million. This metropolitan area is the high technology industrial center of the Pacific Northwest and one of the commercial aircraft manufacturing centers of the United States. The rivers draining the volcano empty into Puget Sound, which has two major shipping ports, and into the Columbia River, a major shipping lane and home to approximately a million people in southwestern Washington and northwestern Oregon. Mount Rainier is an active volcano. It last erupted approximately 150 years ago, and numerous large floods and debris flows have been generated on its slopes during this century. More than 100,000 people live on the extensive mudflow deposits that have filled the rivers and valleys draining the volcano during the past 10,000 years. A major volcanic eruption or debris flow could kill thousands of residents and cripple the economy of the Pacific Northwest. Despite the potential for such danger, Mount Rainier has received little study. Most of the geologic work on Mount Rainier was done more than two decades ago. Fundamental topics such as the development, history, and stability of the volcano are poorly understood.

  20. [Water cults on Soratte Mount].

    PubMed

    Falchetti, Mario; Ottini, Laura

    2011-01-01

    Mount Soratte is a limestone ridge that rises on a lonely plateau of Pliocene tuff on the right of the Tiber, about forty kilometers North of Rome. Studies related to human settlements during prehistory in this territory have been sporadic and occasional. The first evidence of prehistoric cults on mount Soratte has been found in the early Fifties when ajar, dating back to Neolithic times, was discovered in the cave of the Meri. The jar was placed in a position to be always filled of water and indicates the existence of ancient practices of worship linked to groundwater. In the Middle Ages, although caves became a step towards the Hell, dripping caves were often associated with the magical-religious and therapeutic aspects of water linked to fertility in the popular imagination. In the cave church of the Saint Romana, on the eastern slope of Mount Soratte close to Meri, there is a small marble basin near the altar and the water drips from the rock above it. This water is taken out for devotion and drunk by mothers who did not get milk from their breasts. Recently, the water of the Saint Romana would have drained as a result of an act of sacrilege, albeit unintentionally, as reported in a oral testimony. Overall, the territory of Mount Soratte is characterized by a sharp and clear karst. This causes the water, that collects on the inside, coming out in many springs all around the valley. This water is collected to supply fountains used years ago by farmers and livestock and nowadays may represent a cultural space of social life with the aim to build a strong link with the territory and a new awareness of the past and history of the countryside around Mount Soratte. PMID:23057207

  1. Head injury.

    PubMed

    Hureibi, K A; McLatchie, G R

    2010-05-01

    Head injury is one of the commonest injuries in sport. Most are mild but some can have serious outcomes. Sports medicine doctors should be able to recognise the clinical features and evaluate athletes with head injury. It is necessary during field assessment to recognise signs and symptoms that help in assessing the severity of injury and making a decision to return-to-play. Prevention of primary head injury should be the aim. This includes protective equipment like helmets and possible rule changes. PMID:20533694

  2. Helmet-mounted sensor fusion ATR for the dismounted soldier

    NASA Astrophysics Data System (ADS)

    Topiwala, Pankaj N.; Casasent, David

    2004-09-01

    Computer vision capabilities have long been available to advanced sensor systems such as those on aircraft, UAVs, helicopters, and ground scout vehicles; but to date, they have not been available to the dismounted soldier. This is understandable since the size/weight/cost metrics of carrying sensors and the image processing, interaction, and display capabilities, not to mention the power supply, have been prohibitive. But recent advances in uncooled IR sensors (up to QVGA), coupled with the steady advances in EO sensors (VGA+) and in microelectronics, are now making the prospect of computer vision for the foot soldier feasible for the first time. In this paper, we develop our initial approaches to all aspects of this problem: (a) sensor system integration, (b) image processing algorithms and initial hardware vision, and (c) display and interaction. As a prototype compute/display platform, we do initial development based on a lightweight commercial wearable computer and helmet-mounted display.

  3. Takeoff Performance Monitoring System display options

    NASA Technical Reports Server (NTRS)

    Middleton, David B.; Srivatsan, Raghavachari; Person, Lee H., Jr.

    1992-01-01

    The development of displays for the Takeoff Performance Monitoring System (TPMS) is described with attention given to the three concepts prepared for commercial applications. The TPMS algorithm is described and related to the display requirements for pilots of two-engine airplanes. Head-up and -down displays are considered for displaying the simple advisory data which indicate whether the takeoff is a 'Go' or 'No-go' based on engine failure, acceleration error, and runway length. Six pilots are shown the three display options which include: (1) basic information; (2) basic data with 'Go/No-go' advisory flags; and (3) basic data, advisory flags, and an abort-warning symbol. The pilots tended to select the option with the most advisory data available, but the inconclusive preference study led to the concept of presenting all three configurations as possible display options for the TPMS.

  4. Using wintergreen oil for mounting mosquito larvae: a safer alternative to xylene.

    PubMed

    Koay, J B; Natasya, N N; Nashithatul, Mag; Ihsanuddin, R; Salleh, F M; Azil, A H

    2016-01-01

    Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents.

  5. Using wintergreen oil for mounting mosquito larvae: a safer alternative to xylene.

    PubMed

    Koay, J B; Natasya, N N; Nashithatul, Mag; Ihsanuddin, R; Salleh, F M; Azil, A H

    2016-01-01

    Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents. PMID:26528914

  6. A virtual reality oriented clinical experiment on post-stroke rehabilitation: performance and preference comparison among different stereoscopic displays­

    NASA Astrophysics Data System (ADS)

    Yeh, Shih-Ching; Rizzo, Albert; Sawchuk, Alexander A.

    2007-02-01

    We have developed a novel VR task: the Dynamic Reaching Test, that measures human forearm movement in 3D space. In this task, three different stereoscopic displays: autostereoscopic (AS), shutter glasses (SG) and head mounted display (HMD), are used in tests in which subjects must catch a virtual ball thrown at them. Parameters such as percentage of successful catches, movement efficiency (subject path length compared to minimal path length), and reaction time are measured to evaluate differences in 3D perception among the three stereoscopic displays. The SG produces the highest percentage of successful catches, though the difference between the three displays is small, implying that users can perform the VR task with any of the displays. The SG and HMD produced the best movement efficiency, while the AS was slightly less efficient. Finally, the AS and HMD produced similar reaction times that were slightly higher (by 0.1 s) than the SG. We conclude that SG and HMD displays were the most effective, but only slightly better than the AS display.

  7. Head Injuries

    MedlinePlus

    ... before. Often, the injury is minor because your skull is hard and it protects your brain. But ... injuries can be more severe, such as a skull fracture, concussion, or traumatic brain injury. Head injuries ...

  8. Head Noises.

    ERIC Educational Resources Information Center

    Senior, Tom

    2000-01-01

    Explains how a toy called "Sound Bites" can be modified to demonstrate the transmission of sound waves. Students can hear music from the toy when they press it against any bone in their heads or shoulders. (WRM)

  9. Display formats manual

    NASA Technical Reports Server (NTRS)

    Runnels, R. L.

    1973-01-01

    The standards and procedures for the generation of operational display formats to be used in the Mission Control Center (MCC) display control system are presented. The required effort, forms, and fundamentals for the design, specifications, and production of display formats are identified. The principles of display design and system constraints controlling the creation of optimum operational displays for mission control are explained. The basic two types of MCC display systems for presenting information are described.

  10. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... accelerations at the location of the accelerometers mounted in the head in accordance with § 572.36(c) shall not be less than 225g, and not more than 275g. The acceleration/time curve for the test shall be unimodal to the extent that oscillations occurring after the main acceleration pulse are less than ten...

  11. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... accelerations at the location of the accelerometers mounted in the head in accordance with § 572.36(c) shall not be less than 225g, and not more than 275g. The acceleration/time curve for the test shall be unimodal to the extent that oscillations occurring after the main acceleration pulse are less than ten...

  12. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... accelerations at the location of the accelerometers mounted in the head in accordance with § 572.36(c) shall not be less than 225g, and not more than 275g. The acceleration/time curve for the test shall be unimodal to the extent that oscillations occurring after the main acceleration pulse are less than ten...

  13. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... accelerations at the location of the accelerometers mounted in the head in accordance with § 572.36(c) shall not be less than 225g, and not more than 275g. The acceleration/time curve for the test shall be unimodal to the extent that oscillations occurring after the main acceleration pulse are less than ten...

  14. 49 CFR 572.32 - Head.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... accelerations at the location of the accelerometers mounted in the head in accordance with § 572.36(c) shall not be less than 225g, and not more than 275g. The acceleration/time curve for the test shall be unimodal to the extent that oscillations occurring after the main acceleration pulse are less than ten...

  15. A tactual display aid for primary flight training

    NASA Technical Reports Server (NTRS)

    Gilson, R. D.

    1979-01-01

    A means of flight instruction is discussed. In addition to verbal assistance, control feedback was continously presented via a nonvisual means utilizing touch. A kinesthetic-tactile (KT) display was used as a readout and tracking device for a computer generated signal of desired angle of attack during the approach and landing. Airspeed and glide path information was presented via KT or visual heads up display techniques. Performance with the heads up display of pitch information was shown to be significantly better than performance with the KT pitch display. Testing without the displays showed that novice pilots who had received tactile pitch error information performed both pitch and throttle control tasks significantly better than those who had received the same information from the visual heads up display of pitch during the test series of approaches to landing.

  16. Comparison of head-steered and aircraft-fixed infrared imagery for employing the AGM-65 Maverick missile

    NASA Astrophysics Data System (ADS)

    Osgood, Robert K.; Wells, Maxwell J.; Meador, Douglas P.

    1995-05-01

    Eight veteran USAF fighter pilots, experienced with AGM-65 Maverick air-to-ground missiles, flew a night, low-level ground attack mission in a flight simulator equipped with a helmet-mounted display (HMD). The mission was performed by delivering five Maverick missiles against ground vehicles using either an aircraft-fixed forward-looking infrared (FLIR) sensor image on a head-up display (HUD) or a head-steered FLIR as the missile aiming device. Additionally, the pilots employed their weapons by two methods: fixing and launching missiles singly or in varying numbers (multiple method). The purpose of the experiment was to determine what, if any, advantage there is to employing the AGM-65 using the HMD FLIR image to slew the missile seeker onto the target versus the conventional method of using the FLIR image displayed on the HUD. With a head-steered sensor (and fixing and launching weapons singly) subjects released their weapons quicker (14.6 second interval between launches vs. 17.1 sec.), at a higher altitude (1739 feet vs. 1603 ft.), and slightly farther from the target (3.42 nautical miles vs. 3.37 nm). Furthermore, data indicated the pilots looked farther off-boresight when searching for and locking the weapon onto a target, thereby more effectively using the full field-of-regard of the missile seeker. The participants also contributed their opinions of the advantages and disadvantages of the two mechanizations.

  17. Methods and apparatus for transparent display using scattering nanoparticles

    DOEpatents

    Hsu, Chia Wei; Qiu, Wenjun; Zhen, Bo; Shapira, Ofer; Soljacic, Marin

    2016-05-10

    Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

  18. Evolution: Five Heads Are Better Than One.

    PubMed

    Phillips, Patrick C

    2016-04-01

    Three newly discovered species of fig-living nematodes display remarkable diversity in head morphology depending on their local environment. This shows that a great deal of ecological diversity can be maintained in the absence of substantial genetic variation.

  19. Sample mounts for microcrystal crystallography

    NASA Technical Reports Server (NTRS)

    Thorne, Robert E. (Inventor); Stum, Zachary (Inventor); O'Neill, Kevin (Inventor); Kmetko, Jan (Inventor)

    2007-01-01

    Sample mounts (10) for mounting microcrystals of biological macromolecules for X-ray crystallography are prepared by using patterned thin polyimide films (12) that have curvature imparted thereto, for example, by being attached to a curved outer surface of a small metal rod (16). The patterned film (12) preferably includes a tapered tip end (24) for holding a crystal. Preferably, a small sample aperture is disposed in the film for reception of the crystal. A second, larger aperture can also be provided that is connected to the sample aperture by a drainage channel, allowing removal of excess liquid and easier manipulation in viscous solutions. The curvature imparted to the film (12) increases the film's rigidity and allows a convenient scoop-like action for retrieving crystals. The polyimide contributes minimally to background and absorption, and can be treated to obtain desired hydrophobicity or hydrophilicity.

  20. Sample mounts for microcrystal crystallography

    NASA Technical Reports Server (NTRS)

    Thorne, Robert E. (Inventor); Stum, Zachary (Inventor); O'Neill, Kevin (Inventor); Kmetko, Jan (Inventor)

    2009-01-01

    Sample mounts (10) for mounting microcrystals of biological macromolecules for X-ray crystallography are prepared by using patterned thin polyimide films (12) that have curvature imparted thereto, for example, by being attached to a curved outer surface of a small metal rod (16). The patterned film (12) preferably includes a tip end (24) for holding a crystal. Preferably, a small sample aperture is disposed in the film for reception of the crystal. A second, larger aperture can also be provided that is connected to the sample aperture by a drainage channel, allowing removal of excess liquid and easier manipulation in viscous solutions. The curvature imparted to the film (12) increases the film's rigidity and allows a convenient scoop-like action for retrieving crystals. The polyimide contributes minimally to background and absorption, and can be treated to obtain desired hydrophobicity or hydrophilicity.

  1. Simulator scene display evaluation device

    NASA Technical Reports Server (NTRS)

    Haines, R. F. (Inventor)

    1986-01-01

    An apparatus for aligning and calibrating scene displays in an aircraft simulator has a base on which all of the instruments for the aligning and calibrating are mounted. Laser directs beam at double right prism which is attached to pivoting support on base. The pivot point of the prism is located at the design eye point (DEP) of simulator during the aligning and calibrating. The objective lens in the base is movable on a track to follow the laser beam at different angles within the field of vision at the DEP. An eyepiece and a precision diopter are movable into a position behind the prism during the scene evaluation. A photometer or illuminometer is pivotable about the pivot into and out of position behind the eyepiece.

  2. A simple device for high-precision head image registration: Preliminary performance and accuracy tests

    SciTech Connect

    Pallotta, Stefania

    2007-05-15

    The purpose of this paper is to present a new device for multimodal head study registration and to examine its performance in preliminary tests. The device consists of a system of eight markers fixed to mobile carbon pipes and bars which can be easily mounted on the patient's head using the ear canals and the nasal bridge. Four graduated scales fixed to the rigid support allow examiners to find the same device position on the patient's head during different acquisitions. The markers can be filled with appropriate substances for visualisation in computed tomography (CT), magnetic resonance, single photon emission computer tomography (SPECT) and positron emission tomography images. The device's rigidity and its position reproducibility were measured in 15 repeated CT acquisitions of the Alderson Rando anthropomorphic phantom and in two SPECT studies of a patient. The proposed system displays good rigidity and reproducibility characteristics. A relocation accuracy of less than 1,5 mm was found in more than 90% of the results. The registration parameters obtained using such a device were compared to those obtained using fiducial markers fixed on phantom and patient heads, resulting in differences of less than 1 deg. and 1 mm for rotation and translation parameters, respectively. Residual differences between fiducial marker coordinates in reference and in registered studies were less than 1 mm in more than 90% of the results, proving that the device performed as accurately as noninvasive stereotactic devices. Finally, an example of multimodal employment of the proposed device is reported.

  3. Mounting support for a photovoltaic module

    DOEpatents

    Brandt, Gregory Michael; Barsun, Stephan K.; Coleman, Nathaniel T.; Zhou, Yin

    2013-03-26

    A mounting support for a photovoltaic module is described. The mounting support includes a foundation having an integrated wire-way ledge portion. A photovoltaic module support mechanism is coupled with the foundation.

  4. Electrochromic display device

    NASA Astrophysics Data System (ADS)

    Nicholson, M. M.

    1984-07-01

    This invention relates to electrochromic devices. In one aspect it relates to electrically controllable display devices. In another aspect it relates to electrically tunable optical or light filters. In yet another aspect it relates to a chemical sensor device which employs a color changing film. There are many uses for electrically controllable display devices. A number of such devices have been in commercial use for some time. These display devices include liquid crystal displays, light emitting diode displays, plasma displays, and the like. Light emitting diode displays and plasma display panels both suffer from the fact that they are active. Light emissive devices which require substantial power for their operation, In addition, it is difficult to fabricate light emitting diode displays in a manner which renders them easily distinguishable under bright ambient illumination. Liquid crystal displays suffer from the disadvantage that they are operative only over a limited temperature range and have substantially no memory within the liquid crystal material.

  5. Apparent Brecciation Gradient, Mount Desert Island, Maine

    NASA Astrophysics Data System (ADS)

    Hawkins, A. T.; Johnson, S. E.

    2004-05-01

    Mount Desert Island, Maine, comprises a shallow level, Siluro-Devonian igneous complex surrounded by a distinctive breccia zone ("shatter zone" of Gilman and Chapman, 1988). The zone is very well exposed on the southern and eastern shores of the island and provides a unique opportunity to examine subvolcanic processes. The breccia of the Shatter Zone shows wide variation in percent matrix and clast, and may represent a spatial and temporal gradient in breccia formation due to a single eruptive or other catastrophic volcanic event. The shatter zone was divided into five developmental stages based on the extent of brecciation: Bar Harbor Formation, Sols Cliffs breccia, Seeley Road breccia, Dubois breccia, and Great Head breccia. A digital camera was employed to capture scale images of representative outcrops using a 0.5 m square Plexiglas frame. Individual images were joined in Adobe Photoshop to create a composite image of each outcrop. The composite photo was then exported to Adobe Illustrator, which was used to outline the clasts and produce a digital map of the outcrop for analysis. The fractal dimension (Fd) of each clast was calculated using NIH Image and a Euclidean distance mapping method described by Bérubé and Jébrak (1999) to quantify the morphology of the fragments, or the complexity of the outline. The more complex the fragment outline, the higher the fractal dimension, indicating that the fragment is less "mature" or has had less exposure to erosional processes, such as the injection of an igneous matrix. Sols Cliffs breccia has an average Fd of 1.125, whereas Great Head breccia has an average Fd of 1.040, with the stages between having intermediate values. The more complex clasts of the Sols Cliffs breccia with a small amount (26.38%) of matrix material suggests that it is the first stage in a sequence of brecciation ending at the more mature, matrix-supported (71.37%) breccia of Great Head. The results of this study will be used to guide isotopic

  6. Ergonomic design considerations for an optical data link between a warfighter's head and body-worn technologies

    NASA Astrophysics Data System (ADS)

    Trew, Noel; Linn, Aaron; Nelson, Zac; Burnett, Greg; Sedillo, Mike

    2012-06-01

    Today, warfighters are burdened by a web of cables linking technologies that span the head and torso regions of the body. These cables help to provide interoperability between helmet-worn peripherals such as head mounted displays (HMDs), cameras, and communication equipment with chest-worn computers and radios. Although promoting enhanced capabilities, this cabling also poses snag hazards and makes it difficult for the warfighter to extricate himself from his kit when necessary. A newly developed wireless personal area network (WPAN), one that uses optical transceivers, may prove to be an acceptable alternative to traditional cabling. Researchers at the Air Force Research Laboratory's 711th Human Performance Wing are exploring how best to mount the WPAN transceivers to the body in order to facilitate unimpeded data transfer while also maintaining the operator's natural range of motion. This report describes the two-step research process used to identify the performance limitations and usability of a body-worn optical wireless system. Firstly, researchers characterized the field of view for the current generation of optical WPAN transceivers. Then, this field of view was compared with anthropometric data describing the range of motion of the cervical vertebrae to see if the data link would be lost at the extremes of an operator's head movement. Finally, this report includes an additional discussion of other possible military applications for an optical WPAN.

  7. System status display information

    NASA Technical Reports Server (NTRS)

    Summers, L. G.; Erickson, J. B.

    1984-01-01

    The system Status Display is an electronic display system which provides the flight crew with enhanced capabilities for monitoring and managing aircraft systems. Guidelines for the design of the electronic system displays were established. The technical approach involved the application of a system engineering approach to the design of candidate displays and the evaluation of a Hernative concepts by part-task simulation. The system engineering and selection of candidate displays are covered.

  8. Flush Mounting Of Thin-Film Sensors

    NASA Technical Reports Server (NTRS)

    Moore, Thomas C., Sr.

    1992-01-01

    Technique developed for mounting thin-film sensors flush with surfaces like aerodynamic surfaces of aircraft, which often have compound curvatures. Sensor mounted in recess by use of vacuum pad and materials selected for specific application. Technique involves use of materials tailored to thermal properties of substrate in which sensor mounted. Together with customized materials, enables flush mounting of thin-film sensors in most situations in which recesses for sensors provided. Useful in both aircraft and automotive industries.

  9. Mount St. Helens and Kilauea volcanoes

    USGS Publications Warehouse

    Barrat, J.

    1989-01-01

    From the south, snow-covered Mount St. Helens looms proudly under a fleecy halo of clouds, rivaling the majestic beauty of neighboring Mount Rainer, Mount Hood, and Mount Adams. Salmon fishermen dot the shores of lakes and streams in the mountain's shadow, trucks loaded with fresh-cut timber barrel down backroads, and deer peer out from stands of tall fir trees. 

  10. Holding fixture for metallographic mount polishing

    DOEpatents

    Barth, Clyde H.; Cramer, Charles E.

    1997-01-01

    A fixture for holding mounted specimens for polishing, having an arm; a body attached to one end of the arm, the body having at least one flange having an opening to accommodate a mounted specimen; and a means applying pressure against the outer surface of the mounted specimen to hold the specimen in contact with the polishing surface.

  11. Video interfacing to flat panel displays for dynamic graphics portrayal

    NASA Astrophysics Data System (ADS)

    Schiavone, J. J.

    This paper describes the basic process required to convert standard raster video signals to dot addressable matrix displays. The concepts developed were applied to a Litton Systems Advanced Development Model (ADM-1) multimode matrix light emitting diode (LED) display. The ADM-1 display head (320 x 256 pixel format) requires a unique digital interface that is not compatible with other forms of matrix displays. Although this paper describes the details of interfacing to this particular display, the concepts developed apply to all matrix display systems.

  12. Geology and geochemistry of the Mount Riley-Mount Cox pluton, Dona Ana County, New Mexico

    SciTech Connect

    Zimbelman, D.R.; Siems, D.F.; Kilburn, J.E.; Hubert, A.E.

    1985-01-01

    The Mount Riley-Mount Cox area is comprised of a relatively homogeneous pluton of rhyodacite rising some 1600 feet above the La Mesa surface. The pluton, of apparent Tertiary age, intrudes Cretaceous sedimentary rocks and Tertiary ( ) latite and tuff. The rhyodacite is holocrystalline, light gray to pinkish gray, porphyritic to microporphyritic, and locally banded. Phenocrysts include hornblende, quartz, biotite, and calcite. The phenocrysts range in size from 0.2 to 2 mm and make up one to fifteen percent of the rock. The phenocrysts often display a glomerophyric texture within a trachytic groundmass. The groundmass ranges from cryptocrystalline to very fine grained and is composed of plagioclase, quartz, potassium feldspar, hornblende/biotite, and iron-oxide material. Locally, the rhyodacite displays millimeter-scale banding and a poikilitic texture consisting of quartz oikiocrysts and plagioclase chadocrysts. The rhyodacite averages 68.74%, SiO/sub 2/, 0.39% TiO/sub 2/, 16.40% Al/sub 2/O/sub 3/, 2.87% Fe/sub t/, 0.10% MnO, 1.21% MgO, 2.56% CaO, 3.79% Na/sub 2/O, and 3.96% K/sub 2/O. The rhyodacite is cut by veins and veinlets of brown to white calcite. The veins attain a maximum thickness of one meter, are locally bordered by calcite-cemented breccia zones, and locally include pyrite. The veins trend north or northwest, consistent with regional trends for the Rio Grande rift and the Texas Lineament, respectively. Sixty-five samples of rhyodacite, breccia, and vein were analyzed for 31 elements by emission-spectrographic methods. Trace-element data suggestive of hydrothermal mineralization was not recognized.

  13. Definition of display/control requirements for assault transport night/adverse weather capability

    NASA Technical Reports Server (NTRS)

    Milelli, R. J.; Mowery, G. W.; Pontelandolfo, C.

    1982-01-01

    A Helicopter Night Vision System was developed to improve low-altitude night and/or adverse weather assult transport capabilities. Man-in-the-loop simulation experiments were performed to define the minimum display and control requirements for the assult transport mission and investigate forward looking infrared sensor requirements, along with alternative displays such as panel mounted displays (PMD) helmet mounted displays (HMD), and integrated control display units. Also explored were navigation requirements, pilot/copilot interaction, and overall cockpit arrangement. Pilot use of an HMD and copilot use of a PMD appear as both the preferred and most effective night navigation combination.

  14. Seamless tiled display system

    NASA Technical Reports Server (NTRS)

    Dubin, Matthew B. (Inventor); Larson, Brent D. (Inventor); Kolosowsky, Aleksandra (Inventor)

    2006-01-01

    A modular and scalable seamless tiled display apparatus includes multiple display devices, a screen, and multiple lens assemblies. Each display device is subdivided into multiple sections, and each section is configured to display a sectional image. One of the lens assemblies is optically coupled to each of the sections of each of the display devices to project the sectional image displayed on that section onto the screen. The multiple lens assemblies are configured to merge the projected sectional images to form a single tiled image. The projected sectional images may be merged on the screen by magnifying and shifting the images in an appropriate manner. The magnification and shifting of these images eliminates any visual effect on the tiled display that may result from dead-band regions defined between each pair of adjacent sections on each display device, and due to gaps between multiple display devices.

  15. Applications of the Scorpion color helmet-mounted cueing system

    NASA Astrophysics Data System (ADS)

    Atac, Robert

    2010-04-01

    The innovative technology utilized in the Scorpion HMCS has broken several product and price barriers which now allow it to be used in both traditional and non-traditional applications. In particular, its bright color display provides a new dimension for informational content and vastly improved situational awareness. Users are just beginning to explore the ways that color can be used in an HMD projection display. Scorpion has also broken through price and installation cost barriers allowing, for the first time, its use on platforms that could otherwise never have afforded a helmet mounted display. Scorpion HMCS units are currently being used for both traditional cueing as well as unique new applications in both airborne and maritime platforms. These applications are further described as well as other potential roles for the Scorpion HMCS.

  16. Lahars of Mount Pinatubo, Philippines

    USGS Publications Warehouse

    Newhall, Christopher G.; Stauffer, Peter H.; Hendley, James W.

    1997-01-01

    On June 15, 1991, Mount Pinatubo in the Philippines exploded in the second largest volcanic eruption on Earth this century. This eruption deposited more than 1 cubic mile (5 cubic kilometers) of volcanic ash and rock fragments on the volcano's slopes. Within hours, heavy rains began to wash this material down into the surrounding lowlands in giant, fast-moving mudflows called lahars. In the next four rainy seasons, lahars carried about half of the deposits off the volcano, causing even more destruction in the lowlands than the eruption itself.

  17. Apollo Telescope Mount Thermal Unit

    NASA Technical Reports Server (NTRS)

    1970-01-01

    The Apollo Telescope Mount (ATM) was designed and developed by the Marshall Space Flight Center (MSFC) and served as the primary scientific instrument unit aboard Skylab (1973-1979). The ATM consisted of eight scientific instruments as well as a number of smaller experiments. This image is of the ATM thermal unit being tested in MSFC's building 4619. The thermal unit consisted of an active fluid-cooling system of water and methanol that was circulated to radiators on the outside of the canister. The thermal unit provided temperature stability to the ultrahigh resolution optical instruments that were part of the ATM.

  18. Pedestrian Navigation Using Foot-Mounted Inertial Sensor and LIDAR

    PubMed Central

    Pham, Duy Duong; Suh, Young Soo

    2016-01-01

    Foot-mounted inertial sensors can be used for indoor pedestrian navigation. In this paper, to improve the accuracy of pedestrian location, we propose a method using a distance sensor (LIDAR) in addition to an inertial measurement unit (IMU). The distance sensor is a time of flight range finder with 30 m measurement range (at 33.33 Hz). Using a distance sensor, walls on corridors are automatically detected. The detected walls are used to correct the heading of the pedestrian path. Through experiments, it is shown that the accuracy of the heading is significantly improved using the proposed algorithm. Furthermore, the system is shown to work robustly in indoor environments with many doors and passing people. PMID:26797619

  19. Pedestrian Navigation Using Foot-Mounted Inertial Sensor and LIDAR.

    PubMed

    Pham, Duy Duong; Suh, Young Soo

    2016-01-01

    Foot-mounted inertial sensors can be used for indoor pedestrian navigation. In this paper, to improve the accuracy of pedestrian location, we propose a method using a distance sensor (LIDAR) in addition to an inertial measurement unit (IMU). The distance sensor is a time of flight range finder with 30 m measurement range (at 33.33 Hz). Using a distance sensor, walls on corridors are automatically detected. The detected walls are used to correct the heading of the pedestrian path. Through experiments, it is shown that the accuracy of the heading is significantly improved using the proposed algorithm. Furthermore, the system is shown to work robustly in indoor environments with many doors and passing people. PMID:26797619

  20. Uncovering East Antarctic Bedrock using detrital zircon geochronology and pebble lithologies from Mount Howe, Scott Glacier

    NASA Astrophysics Data System (ADS)

    Dits, T.; Licht, K.; Bader, N.; Kaplan, M. R.; Schaefer, J. M.; Winckler, G.

    2012-12-01

    Till from the flanks of Mount Howe, the southernmost outcrop in the world at the head of the Scott Glacier, Antarctica, offers an exclusive view of East Antarctic bedrock through analysis of detrital zircon geochronology and pebble lithology. With no outcrops upstream of the Mount Howe nunatak, detrital zircons and pebbles incorporated in the supraglacial till place direct new age and lithologic constraints on unmapped, ice covered bedrock in the Scott Glacier catchment. Nine moraine crests were sampled along a 2 km transect from the modern ice edge toward exposed Beacon Supergroup bedrock, where rock weathering increases away from the ice margin. Preliminary cosmogenic ages on boulders on the same crests as the provenance study indicate most of the moraine complex formed over the last 100 ka, but some ridges close to the headwall may be much older. Pebble lithologies across the transect show minimal statistical variation, averaging 60% mafic igneous, 30% metamorphic, and 10% sedimentary lithologies dominantly from the Ferrar and Beacon Supergroups. Observations of faceting and striations on pebble surfaces reveal that up to 40-50% of the pebble fraction of the till was subglacially transported, and a minimum of 15% are exotic lithologies. Nearly 80% of cobbles collected from a non-random survey reveal the presence of several exotic rock types, including vesicular olivine basalt, quartzite, and four different compositions of granite. Guided by backscatter electron imagery of detrital zircons, 385 ages from U-Pb isotopes of detrital zircons from 8 sequential moraine crests were determined by laser ablation-inductively coupled plasma mass spectroscopy (LA-ICPMS). Distinct age populations were identified at 185-190 Ma, 255-270 Ma, 355-365 Ma, 550-580 Ma, and 2740 Ma. Four samples in the middle of the transect all display a similar 1010-1040 Ma peak that is statistically different from the remaining samples. The 185 Ma population differs from the typical East Antarctic

  1. Exploring interaction with 3D volumetric displays

    NASA Astrophysics Data System (ADS)

    Grossman, Tovi; Wigdor, Daniel; Balakrishnan, Ravin

    2005-03-01

    Volumetric displays generate true volumetric 3D images by actually illuminating points in 3D space. As a result, viewing their contents is similar to viewing physical objects in the real world. These displays provide a 360 degree field of view, and do not require the user to wear hardware such as shutter glasses or head-trackers. These properties make them a promising alternative to traditional display systems for viewing imagery in 3D. Because these displays have only recently been made available commercially (e.g., www.actuality-systems.com), their current use tends to be limited to non-interactive output-only display devices. To take full advantage of the unique features of these displays, however, it would be desirable if the 3D data being displayed could be directly interacted with and manipulated. We investigate interaction techniques for volumetric display interfaces, through the development of an interactive 3D geometric model building application. While this application area itself presents many interesting challenges, our focus is on the interaction techniques that are likely generalizable to interactive applications for other domains. We explore a very direct style of interaction where the user interacts with the virtual data using direct finger manipulations on and around the enclosure surrounding the displayed 3D volumetric image.

  2. Dual resolution, vacuum compatible optical mount

    DOEpatents

    Halpin, John Michael

    2011-10-04

    An optical mount for an optical element includes a mounting plate, a lever arm pivot coupled to mounting plate, and an adjustment plate. The optical mount also includes a flexure pivot mechanically coupling the adjustment plate to the mounting plate and a lever arm. The optical mount further includes a first adjustment device extending from the adjustment plate to make contact with the lever arm at a first contact point. A projection of a line from the first contact point to a pivot point, measured along the lever arm, is a first predetermined distance. The optical mount additionally includes a second adjustment device extending from the adjustment plate to make contact with the lever arm at a second contact point. A projection of a line from the second contact point to the pivot point, measured along the lever arm, is a second predetermined distance greater than the first predetermined distance.

  3. Nozzle and shroud assembly mounting structure

    DOEpatents

    Faulder, Leslie J.; Frey, deceased, Gary A.; Nielsen, Engward W.; Ridler, Kenneth J.

    1997-01-01

    The present nozzle and shroud assembly mounting structure configuration increases component life and reduces maintenance by reducing internal stress between the mounting structure having a preestablished rate of thermal expansion and the nozzle and shroud assembly having a preestablished rate of thermal expansion being less than that of the mounting structure. The mounting structure includes an outer sealing portion forming a cradling member in which an annular ring member is slidably positioned. The mounting structure further includes an inner mounting portion to which a hooked end of the nozzle and shroud assembly is attached. As the inner mounting portion expands and contracts, the nozzle and shroud assembly slidably moves within the outer sealing portion.

  4. Nozzle and shroud assembly mounting structure

    DOEpatents

    Faulder, L.J.; Frey, G.A.; Nielsen, E.W.; Ridler, K.J.

    1997-08-05

    The present nozzle and shroud assembly mounting structure configuration increases component life and reduces maintenance by reducing internal stress between the mounting structure having a preestablished rate of thermal expansion and the nozzle and shroud assembly having a preestablished rate of thermal expansion being less than that of the mounting structure. The mounting structure includes an outer sealing portion forming a cradling member in which an annular ring member is slidably positioned. The mounting structure further includes an inner mounting portion to which a hooked end of the nozzle and shroud assembly is attached. As the inner mounting portion expands and contracts, the nozzle and shroud assembly slidably moves within the outer sealing portion. 3 figs.

  5. Liver transplantation at Mount Sinai.

    PubMed

    Kim-Schluger, L; Florman, S S; Gondolesi, G; Emre, S; Sheiner, P A; Fishbein, T M; Schwartz, M E; Miller, C M

    2000-01-01

    Nearly 2000 liver transplants have been performed over the past 12 years at Mount Sinai, with a recent exponential growth in living donor surgeries. Living-donor liver transplantation has emerged as an important option for our patients with end-stage liver disease. We are only beginning to recognize fully the advantages that 'scheduled' liver transplantation can offer. In this era of severe cadaver organ shortages, living donation offers patients the option of liver replacement in a timely fashion, before life-threatening complications of hepatic failure and/or carcinoma progression prohibit transplantation. The next era of transplantation at Mount Sinai will bring significant increases in the number of transplants performed with living donors, with projections of over 50% of the total transplants each year expected to involve living donations. We are committed to offering this option while recognizing that donor safety remains paramount and cannot be overemphasized. Proper donor and recipient selection, as well as surgical experience are imperative to success with this technically demanding procedure. Recurrent disease after transplantation, particularly with hepatitis C, remains a challenge clinically. Further investigations into the pathogenesis of the rapid progression of recurrent hepatitis C need to be addressed. Living donor transplantation could be an important option for these patients and would allow timely transplantation and the potential for improved survival in patients with hepatocellular carcinoma. PMID:11512318

  6. Side mount universal battery terminal

    SciTech Connect

    Byfield, D. Jr.

    1987-06-16

    An automobile battery is described of the type having side mounted, threaded bolt hole terminal connectors, battery cables having bored disc shaped terminals with peripheral insulating covers and, an improved terminal connector bolt adapted to accommodate the battery cable terminals and other electrical accessory terminals comprising: an elongated body of electrically conducting material having a longitudinal axis and an inner end and an outer end; a first generally cylindrical threaded stud formed on the inner end of the body. The first stud has a length and diameter disposed to permit thread engagement of the stud with one of the side mounted terminal connectors on the battery in electrical connection therewith, and pass through the bore in one of the battery cable terminals; a central portion on the body adjacent to and outwardly from the first stud, the central portion has a peripheral diameter greater than the first stud portion and has a first shoulder surface generally normal to the longitudinal axis of the body facing toward the inner end of the body and disposed to engage the face surface of one of the battery cable terminals in an electrically conducting relationship.

  7. Mount Rainier, a decade volcano

    SciTech Connect

    Kuehn, S.C.; Hooper, P.R. . Dept. of Geology); Eggers, A.E. . Dept. of Geology)

    1993-04-01

    Mount Rainier, recently designated as a decade volcano, is a 14,410 foot landmark which towers over the heavily populated southern Puget Sound Lowland of Washington State. It last erupted in the mid-1800's and is an obvious threat to this area, yet Rainier has received little detailed study. Previous work has divided Rainier into two distinct pre-glacial eruptive episodes and one post-glacial eruptive episode. In a pilot project, the authors analyzed 253 well-located samples from the volcano for 27 major and trace elements. Their objective is to test the value of chemical compositions as a tool in mapping the stratigraphy and understanding the eruptive history of the volcano which they regard as prerequisite to determining the petrogenesis and potential hazard of the volcano. The preliminary data demonstrates that variation between flows is significantly greater than intra-flow variation -- a necessary condition for stratigraphic use. Numerous flows or groups of flows can be distinguished chemically. It is also apparent from the small variation in Zr abundances and considerable variation in such ratios as Ba/Nb that fractional crystallization plays a subordinate role to some form of mixing process in the origin of the Mount Rainier lavas.

  8. Gas cushion control of OVJP print head position

    DOEpatents

    Forrest, Stephen R

    2014-10-07

    An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate so as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.

  9. XVD Image Display Program

    NASA Technical Reports Server (NTRS)

    Deen, Robert G.; Andres, Paul M.; Mortensen, Helen B.; Parizher, Vadim; McAuley, Myche; Bartholomew, Paul

    2009-01-01

    The XVD [X-Windows VICAR (video image communication and retrieval) Display] computer program offers an interactive display of VICAR and PDS (planetary data systems) images. It is designed to efficiently display multiple-GB images and runs on Solaris, Linux, or Mac OS X systems using X-Windows.

  10. Screens and Displays.

    ERIC Educational Resources Information Center

    Edstrom, Malin

    1987-01-01

    Discusses the characteristics of different computer screen technologies including the possible harmful effects on health of cathode ray tube (CRT) terminals. CRT's are compared to other technologies including liquid crystal displays, plasma displays, electroluminiscence displays, and light emitting diodes. A chart comparing the different…

  11. Digital video display system

    NASA Technical Reports Server (NTRS)

    Zygielbaum, A. I.; Martin, W. L.; Engle, A.

    1973-01-01

    System displays image data in real time on 120,000-element raster scan with 2, 4, or 8 shades of grey. Designed for displaying planetary range Doppler data, system can be used for X-Y plotting, displaying alphanumerics, and providing image animation.

  12. Electric power supplying well head assembly

    SciTech Connect

    Reed, L. T.

    1985-01-01

    A well head assembly that terminates on the upper end in a horizontal mounting flange on which the flange of a christmas tree array of valves may be sealingly mounted to control the flow of fluid from the well associated therewith, and the well head assembly including slidably engageable first and second electrical conducting cartridges below the mounting flange for supplying electric power to a number of insulated electrical conductors that extend downwardly in the well to an electric motor driven down hole pump or other electrical apparatus. The positioning of the christmas tree array of valves at a minimum height relative to the well head is most desirable in those situations where a number of wells are drilled close together, such as on an off shore island, and equipment must be periodically moved over the array of valves for maintenance or drilling purposes. The well head assembly also includes means for pressurizing a normally open pressure actuated valve in communication with a tubing string operatively associated with the assembly to place the valve in a closed position. closing of the valve eliminates the possibility of continued undesired fluid discharge from the well in the event of a catastrophe or malfunctioning of the well.

  13. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1996-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  14. Accelerometer Method and Apparatus for Integral Display and Control Functions

    NASA Technical Reports Server (NTRS)

    Bozeman, Richard J., Jr. (Inventor)

    1998-01-01

    Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

  15. Skylab simulator visual displays and training for joint observing programs.

    PubMed

    Holt, A C; da Silva, A J

    1977-04-01

    The complexity of the Skylab Apollo Telescope Mount (ATM) experiment operations necessitated the use of high fidelity simulations of the onboard visual displays and pointing system for crew training. The displays which were simulated included the H-alpha displays, XUV monitor display, XUV/slit/white light display, x-ray image display, and the white light coronagraph display. The pointing simulation was achieved by projecting film sequences which were subsequently viewed by TV cameras. An optical system in front of the vidicons simulated the pointing, roll, and zoom capabilities of the ATM and sensing systems. The simulation enabled the Skylab crewmen to obtain valuable integrated training combining such tasks as target recognition and status assessment, complex and the time dependent pointing operations, malfunction analyses, and rapid responses to flare and other transient events.

  16. In Brief: Mount Wilson centennial

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2008-11-01

    The 60-inch reflecting telescope at Mount Wilson Observatory, in southern California, which helped scientists measure the Milky Way and determine our solar system's position within it, celebrates its 100th anniversary in December. ``The 60-inch continued the Copernican Revolution by dethroning the Sun from the center of our galaxy,'' noted observatory director Harold McAlister. The telescope, with its silver-on-glass reflectors, also established the basic design for observatory telescopes on Earth. Capable of operating in several different optical configurations, the telescope was the first one built primarily for photographic and spectrographic use. With its 5-foot-diameter mirror, the telescope was the largest in the world until 1917. The telescope is retired from active science but is made available to groups for viewing astronomical objects. The observatory was founded by astronomer George Ellery Hale under the auspices of the Carnegie Institution of Washington. For more information, visit http://www.mtwilson.edu.

  17. Cytoplasmic bacteriophage display system

    DOEpatents

    Studier, F. William; Rosenberg, Alan H.

    1998-06-16

    Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest.

  18. Cytoplasmic bacteriophage display system

    DOEpatents

    Studier, F.W.; Rosenberg, A.H.

    1998-06-16

    Disclosed are display vectors comprising DNA encoding a portion of a structural protein from a cytoplasmic bacteriophage, joined covalently to a protein or peptide of interest. Exemplified are display vectors wherein the structural protein is the T7 bacteriophage capsid protein. More specifically, in the exemplified display vectors the C-terminal amino acid residue of the portion of the capsid protein is joined to the N-terminal residue of the protein or peptide of interest. The portion of the T7 capsid protein exemplified comprises an N-terminal portion corresponding to form 10B of the T7 capsid protein. The display vectors are useful for high copy number display or lower copy number display (with larger fusion). Compositions of the type described herein are useful in connection with methods for producing a virus displaying a protein or peptide of interest. 1 fig.

  19. Advanced centering of mounted optics

    NASA Astrophysics Data System (ADS)

    Wenzel, Christian; Winkelmann, Ralf; Klar, Rainer; Philippen, Peter; Garden, Ron; Pearlman, Sasha; Pearlman, Guy

    2016-03-01

    Camera objectives or laser focusing units consist of complex lens systems with multiple lenses. The optical performance of such complex lens systems is dependent on the correct positioning of lenses in the system. Deviations in location or angle within the system directly affect the achievable image quality. To optimize the achievable performance of lens systems, these errors can be corrected by machining the mount of the lens with respect to the optical axis. The Innolite GmbH and Opto Alignment Technology have developed a novel machine for such center turning operation. A confocal laser reflection measurement sensor determines the absolute position of the optical axis with reference to the spindle axis. As a strong advantage compared to autocollimator measurements the utilized Opto Alignment sensor is capable of performing centration and tilt measurements without changing objectives on any radius surface from 2 mm to infinity and lens diameters from 0.5 mm to 300 mm, including cylinder, aspheric, and parabolic surfaces. In addition, it performs significantly better on coated lenses. The optical axis is skewed and offset in reference to the spindle axis as determined by the measurement. Using the information about the mount and all reference surfaces, a machine program for an untrue turning process is calculated from this data in a fully automated manner. Since the optical axis is not collinear with the spindle axis, the diamond tool compensates for these linear and tilt deviations with small correction movements. This results in a simple machine setup where the control system works as an electronic alignment chuck. Remaining eccentricity of <1 μm and angular errors of < 10 sec are typical alignment results.

  20. Characterization of accelerometer mountings in shock environments

    SciTech Connect

    Boatman, V.I.; Solomon, O.M. Jr.

    1986-08-01

    This report describes the shock test characterization of four accelerometer mounting techniques which are: adiprene and wax, polysulfide rubber and wax, restrained adiprene, and hard mount. The mountings have all been used in field tests, and the shock testing provides some simulation of the field test environments. The characteristics of these mountings are analyzed in the time-domain and in the frequency-domain and are compared to the response of a reference accelerometer at two different shock levels, approximately 2 kg and 7 kg. While soft mounting techniques can be used to guarantee acceleratometers survival in severe mechanical environments, this report documents the tested mounting materials to be highly nonlinear. These nonlinearities result in significant data distortion at frequencies above a few hundred hertz.