|
|
|
Title: EXTENDED PHOTOMETRIC MODEL OF FOG EFFECTS ON ROAD VISION
Accession Number: 00977226
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: The road environment projects a luminance distribution into the eyes of the driver. In the presence of fog, the resulting visual signal is disturbed because of light scattering by airborne water droplets. This phenomenon has three major effects, which cause an overall visibility loss: attenuation, halo, and veiling. Koschmieder's law is widely used to describe how fog modifies the visual signal, but it applies only when nonluminous objects are being observed in daytime. In nighttime and with self-luminous objects, luminance from scattered light can no longer be neglected. The optical mechanisms underlying the visual effects of fog have been analyzed. Koschmieder's law was then extended to account for halos and backscattered veil in the disturbed visual signal. The utility and validity of the resulting photometric model were discussed, and an example was provided that illustrates how it can be used to predict the image of a foggy road environment as seen by a driver. Despite its complexity, the model should find many applications, such as driving simulation and aiding device design.
Supplemental Notes: This paper appears in Transportation Research Record No. 1862, Traffic Control Devices, Visibility, and Rail-Highway Grade Crossings 2004.
Monograph Accession #: 00977217
Language: English
Corporate Authors: Transportation Research Board 500 Fifth Street, NW Authors: Dumont, EricCavallo, VPagination: p. 77-81
Publication Date: 2004
Serial: ISBN: 0309094542
Features: Figures
(5)
; References
(13)
TRT Terms: Subject Areas: Highways; Operations and Traffic Management; Safety and Human Factors; I73: Traffic Control
Files: TRIS, TRB, ATRI
Created Date: Aug 27 2004 12:00AM
More Articles from this Serial Issue:
|
