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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-HRT-04-147
Date: December 2005

Enhanced Night Visibility Series, Volume XVI: Phase III—Characterization of Experimental Objects

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General Terms

CCD charged coupled device
ENV Enhanced Night Visibility
HHD high head down
SUV sport utility vehicle
VES vision enhancement system
IR infrared
far IR portion of electromagnetic spectrum from 2.5 micrometers (µm) to 350 µm
N sample size
near IR portion of electromagnetic spectrum from 700 nanometers to 5 µm
FOV field of view
VIS visible light

Vision Enhancement Systems

FIR far infrared vision system
HID 1 high intensity discharge (narrow beam distribution)
HID 2 high intensity discharge (wide beam distribution)
HLB halogen (i.e., tungsten-halogen) low beam
NIR near infrared vision system


BlackLF pedestrian, black clothing, left
BlackRT pedestrian, black clothing, right
BloomLF bloom object, left (denim clothing)
BloomRT bloom object, right (denim clothing)
BlueLF pedestrian, denim clothing, left
BlueRT pedestrian, denim clothing, right
FOALT far off axis left (denim clothing)
FOART far off axis right (denim clothing)
LFtrnLF pedestrian in left turn, left side (denim clothing)
LFtrnRT pedestrian in left turn, right side (denim clothing)
RRPM raised retroreflective pavement marker
RTtrnLF pedestrian in right turn, left side (denim clothing)
RTtrnRT pedestrian in right turn, right side (denim clothing)


delta symbolL luminance difference
delta symbolLth threshold luminance difference
C contrast
cd/m² candela per square meter
cm centimeters
ft feet
fL footlamberts
m meters
mi/h miles per hour
mm millimeters
s seconds
VL visibility level

Calculated Variables

AF age factor
FCP negative contrast factor
L luminance
t observation time
TF time factor


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