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Publication Number: FHWA-HRT-04-145
Date: December 2005

Enhanced Night Visibility Series, Volume XIV: Phase III—Study 2: Comparison of Near Infrared, Far Infrared, and Halogen Headlamps on Object Detection in Nighttime Rain

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General Terms

BATTM Brightness Acuity Tester
ENV Enhanced Night Visibility
LED light emitting diode
NHTSA National Highway Traffic Safety Administration
SUV sport utility vehicle
UV–A ultraviolet A (wavelength 315 to 400 nanometers)
VES vision enhancement system
VMT vehicle miles traveled

Vision Enhancement Systems

HLB halogen (i.e., tungsten-halogen) low beam
HLB–LP halogen low beam at a lower profile
HID high intensity discharge

Statistical Terms

ANOVA analysis of variance
DF degrees of freedom
F value F-ratio
MS mean square
N sample size
P value statistical significance
SNK Student-Newman-Keuls test
SS sums of squares


delta symbol lux calculated change in illuminance at the driver’s eye
cd candela
cd/m2 candela per square meter
cm centimeters
D degrees down
fL footlamberts
ft feet
km/h kilometers per hour
L degrees left
lm lumens
lx lux
m meters
mi miles
mi/h miles per hour
min minutes
ms milliseconds
nm nanometers
R degrees down
s seconds
U degrees up
V volts
W Watts


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