Field Mesurements for Street Lighting Assessment

This paper presents a case study regarding street lighting design and field measurements for a conflict area and the main road entering it. The study consists in three particular parts. The first part is represented by two types of field measurements. The first type of measurements are done with a digital camera that makes picture of the calculation surface which are processed to determine the luminance values on the calculation surfaces. The conversion functions needed to process the images into luminance values is done through a MATLAB R2020 script. The second type of measurements are done with a lux-meter which is set to measure perpendicular light intensity in several points. After taking all measurements, the second part of the study consist in luminance calculation and individual illuminance calculation done for the points from the exact same geometry as the measurements. This can be done by using a design software. For this particular study DIALux Evo 9.1 is used. Utilizing the field measurements and DIALux calculations the paper presents the differences between design and field installations after years of service without a proper maintenance. The most important conclusions of the paper are that conflict areas are not designed correctly, and the light intensity distribution curve for classical street lighting luminaire can change along the life of the equipment, which not only reduces the efficiency of the equipment, but actually it can even generate high light pollution.