Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network

  Advanced Search  

Light Source Halos in Night Vision Goggles: Psychophysical Assessments

Summary: Light Source Halos in Night Vision Goggles: Psychophysical
Greg Craiga
, Todd Macudaa
, Paul Thomasb
, Rob Allisonc
& Sion Jenningsa
National Research Council b
Topaz Technology Inc c
York University
Ottawa, Canada Toronto, Canada Toronto, Canada
Anecdotal reports by pilots flying with Night Vision Goggles (NVGs) in urban environments suggest that halos
produced by bright light sources impact flight performance. The current study developed a methodology to examine the
impact of viewing distance on perceived halo size. This was a first step in characterizing the subtle phenomenon of halo.
Observers provided absolute size estimates of halos generated by a red LED at several viewing distances. Physical
measurements of these halos were also recorded. The results indicated that the perceived halo linear size decreased as
viewing distance was decreased. Further, the data showed that halos subtended a constant visual angle on the goggles
(148', 7') irrespective of distance up to 75'. This invariance with distance may impact pilot visual performance. For


Source: Allison, Robert - Department of Computer Science, York University (Toronto)


Collections: Computer Technologies and Information Sciences; Biology and Medicine