Glare, Luminance, and Illuminance Measurements of Road Lighting Using Vehicle Mounted CCD Cameras

Abstract

The assessment of well-designed road-lighting systems is necessary since their performance can be critically reduced by incorrect installation. During the operational life of a system, it is also necessary to assess the effects of deterioration in the luminaire fittings, changes in road surface or surroundings and changing user needs. An automated vehicle-mounted system constitutes the most practical technical solution to carry out this task. Previous research produced image acquisition and analysis systems for measuring luminance and uniformity levels of road lighting (Glenn 2000). This paper builds on this work and describes the methods employed to assess the combined parameters of luminance, illuminance and glare.A description of the system components is given, including the CCD digital video cameras, which are mounted on the test vehicle. The cameras are pre-calibrated to estimate relationships between gray value of light images and lighting parameters (luminance and illuminance). Appropriate infra-red and neutral density filters are employed to control the wavelength and limit the light entering into the cameras.Differential GPS, 3D orientation sensors, and image flow analysis, are employed to accurately estimate the position of the vehicle. Automated image analysis methods are further developed to speed up the position and image analysis process.Multidirectional measurements of light output are achieved using multiple journeys and multiple cameras on the same road-segment, which provide data on different observation lines. Interpolation techniques are employed to estimate the complete profile and produce isolux contours. Results produced so far indicate that lighting A Zatari:

Evaluation and Improvement of Lighting Efficiency in Working Spaces

“…There are different programs that must be used to evaluate lighting requirements in different kinds of spaces. Most of those programs allow the performance of a quantitative analysis of scenarios, thanks to their capability of creating a 3D virtual world where lighting effects are recreated and analyzed in both artificial lighting and daylighting scenes [20].…”

Smartphones as a Light Measurement Tool: Case of Study

“…These devices are too specialized to be available in many situations where light conditions should be measured. For this reason, some researchers have used CCD (Charge-Coupled Device) cameras to obtain luminance [23,24], glare and illuminance measurements [25]. The utilization of CCD as a luminance meter in order to calculate visibility level has big advantages because it reduces the time required for the measurements.…”

Road Lighting

“…Unfortunately, today this lens is no longer commercially available. Software for CCD luminance meters is being developed that allows for the determination of the veiling luminance by analysing the picture projected on the CCD matrix so as to obtain the luminances of the luminaires together with the individual positions of the luminaires (Zatari et al 2004;Yamada and Kohko 2013). The veiling luminance then follows from the formula:…”