Accession Number : ADA260579


Title :   The Effect of Signal-to-Noise Ratio on Visual Acuity Through Night Vision Goggles


Descriptive Note : Final rept. Oct 1989-Sep 1990


Corporate Author : LOGICON TECHNICAL SERVICES INC DAYTON OH


Personal Author(s) : Riegler, Joseph T ; Whiteley, James D ; Task, H L ; Schueren, James C


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a260579.pdf


Report Date : Feb 1991


Pagination or Media Count : 30


Abstract : 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.


Descriptors :   *SIGNAL TO NOISE RATIO , *NIGHT VISION , *GOGGLES , *VISUAL ACUITY , CONTRAST , ENVIRONMENTS , DEGRADATION , ACUITY , ILLUMINATION , TARGETS , IMAGES , PERSONNEL , NOISE , MOON , TUBES , STARLIGHT


Subject Categories : Optical Detection and Detectors


Distribution Statement : APPROVED FOR PUBLIC RELEASE