Download or read book Visual Acuity with Second and Third Generation Night Vision Goggles Obtained from a New Method of Night Sky Simulation Across a Wide Range of Target Contrast written by and published by . This book was released on 1992 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this investigation was to study the primary factors which influence visual acuity (VA) with night vision goggles (NVGs). These factors are: night sky condition, target contrast, and NVG generation. Improved methods were used to simulate the night sky and to control for differences in target contrast which result from dissimilarities in spectral sensitivity between NVG generations. The new simulation method used combinations of spectrally flat (neutral density) and wavelength selective (blue glass) filters to reproduce the spectral distribution of the night sky across the entire NVG response range. Between-generation differences in target contrast were eliminated by weighting the incident radiant flux by the sensitivity of the detector. It was found that the difference in VA between the two generations widens under two conditions: (1) when target contrast is constant and night sky irradiance decreases, and (2) when night sky irradiance is constant and target contrast decreases. Furthermore, it was found that for a given NVG generation, VA falls off more rapidly for a low contrast target than for one of high contrast when night sky irradiance decreases.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1556 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Evaluation of Visual Acuity with Gen 3 Night Vision Goggles written by and published by . This book was released on 1994 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Forward looking Infrared written by Jeff Rabin and published by . This book was released on 1994 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Selected Papers on Night Vision Technology written by R. Hradaynath and published by SPIE-International Society for Optical Engineering. This book was released on 2001 with total page 1050 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection of 104 papers is divided into two parts. Part One, Image Intensification, focuses on developments with image intensified tubes. Part Two, Thermal Imaging, concentrates on the practical applications of night vision technology for its main users: the armed forces.

Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1130 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Optical Society of America written by and published by . This book was released on 1994 with total page 1216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aerospace Medicine and Biology written by and published by . This book was released on 1992 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA).

Download or read book Head mounted Displays II written by Ronald J. Lewandowski and published by SPIE-International Society for Optical Engineering. This book was released on 1997 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Perception written by and published by . This book was released on 1993 with total page 782 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Current Aeromedical Issues in Rotary Wing Operations written by and published by . This book was released on 1999 with total page 364 pages. Available in PDF, EPUB and Kindle. Book excerpt: Given its characteristics and the complexity of its use and its environment, the helicopter is exposed to damage and a whole series of measures can be previewed to alientate this risk. The presentations concentrated on five main topics: 1. Crew training; 2. The different conditions of use; 3. The psycho-physiological component; 4. Survival equipment and methods; and 5. Accidents and their prevention. A careful reading of the papers presented at the symposium will enable both specialists and decision-makers to make a summary assessment of the constraints of the missions on the one hand, and on the other, of the new methods of protection and training and the new technologies which will enable aircrew to carry out their missions in a safer environment. In addition, they will perhaps discover that helicopter operation can be optimised by a series of different devices and above all by judicious matching of "type of helicopter-type of aircrew training-type of additional on-board equipment".

Download or read book Digest of Technical Papers written by and published by . This book was released on 1994 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigative Ophthalmology Visual Science written by and published by . This book was released on 1993-03 with total page 992 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Government Reports Announcements Index written by and published by . This book was released on 1992 with total page 1602 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Visual Acuity for High Contrast Tri bar Targets Illuminated with Spectra Simulating Night Vision Goggle NVG Displays and the No moon Night Sky written by and published by . This book was released on 2010 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents two studies that measured unaided visual acuity using a 50-in square high-contrast U.S. Air Force (USAF) 1951 Tri-Bar chart viewed from 12 ft at luminance levels ranging from 0.00046 fL (much darker than a night vision goggle [NVG] display of an overcast starlight scene) to 21.5 fL (much brighter than a NVG display of a full-moon scene). To avoid visual noise artifacts, these studies did not use actual NVG displays. The studies were designed to support general modeling efforts at the U.S. Army Research Development and Engineering Command (RDECOM) Communications-Electronics Research Development and Engineering Center (CERDEC), Night Vision and Electronic Sensors Directorate (NVESD). For Study 1, the Tri-Bar chart was back-lit with a spectrum similar to the standard yellowish-green (P43) phosphor NVG display. In Study 2, the chart was back-lit with tungsten illumination, similar to a 2856 K blackbody spectrum. In addition to providing measures of unaided visual acuity, we introduced a new technique-the Green-appearance Scale-to determine the luminance levels at which participants transitioned from scotopic viewing of the Tri-Bar chart to mesopic viewing, and from mesopic viewing to photopic viewing. We describe this technique and present the data as part of the methodology and results of Study 1.

Download or read book Spatial Contrast Sensitivity Through Aviator s Night Vision Imaging System written by J. Rabin and published by . This book was released on 1993 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Signal to Noise Ratio on Visual Acuity Through Night Vision Goggles written by Joseph T. Riegler and published by . This book was released on 1991 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: Since 1971, night vision goggles (NVGs) have been used by the military to enable personnel to perform visual operations in a nighttime environment. The key component of these devices is the image intensifier tube. Currently, no studies were identified which relate the signal-to-noise ratio (SNR) of image intensifiers to human visual acuity. The purpose of the present research was to determine the effect of NVG intensifier tube SNR on visual acuity. Visual acuity, using PVS-7 third generation NVGs, was measured for twelve participants at quarter moon and starlight illumination levels for four intensifier tubes with different SNRs. The range of SNR examined was 11.37 to 17.92. Visual acuity was assessed using Landolt C charts with target contrasts of 20 to 95 percent. The distance at which the acuity targets were resolved was recorded for each of the four illumination and contrast conditions. The results showed that increases in image intensifier tube SNR, illumination level, and contrast affected visual acuity. Regression analyses were performed to obtain estimated equations relating SNR to visual acuity for each experimental condition. The results were used to develop predictive guideline tables to provide approximate percent degradation/ improvement in visual acuity based upon intensifier tube signal-to-noise ratio ... Visual acuity, Night vision goggles, Signal-to-noise ratio, Image intensifier tubes.