Road luminances dealt with digital camera
When using the standards for functional road lighting, the luminaries are generally chosen and retained with respect to their calculated performances in luminances (unit: cd/m2). Unfortunately, site measurements destined to the survey and the control are generally based on illuminances (thats generally the case with luxmeter measurements on standardized grid points) or simply the control are not carried out...If illuminances solely are taken into account, this means that only direct flux coming from the luminaires to the road surface is checked but not the flux reflected by the carriageway to the driver/observers eyes : namely the luminances which are however the relevant parameters for road lighting performance and beyond that vision and visibility.This is a lack that digital measurement devices may avoid. Indeed, since a few years, certain CCD camera types, calibrated on visible V(λ), are used as measurement devices for luminance evaluation. Using this new technology at the exterior laboratory on a test road of Thorn at Les Andelys in France, developed a measurement method of luminances adapted to the road lighting specificities. The method allows providing the level and uniformities of luminance, presenting quicly and directly on a computer screen an image of the measurements on the grid according to the standards corresponding to the calculations and criteria required, generally simulated previously with lighting design software.But beyond the simple control of luminances of a roadway, the numeric tool opens the door at the same time to an interesting goal which is to determine the road surface reflection properties, i.e. the r-tables, from the distribution of luminances of only one luminaire lighting a part of existing carriageways. These data allow to reach immediately the optimised lighting solution for the given road surface.The present paper describes the study from the choice of the luminaire up to the validation issue (control on the test road of theoretical results produced thanks to the r-table) reviewing the description of inescapable steps (including geometrical parameters, calculation software,...)
luminances roadlighting CCD camera
RAMI, Jean-Paul
THORN, Route de paix, 27700 Les Andelys, France
国际会议
26th Session of the CIE(国际照明委员会（CIE）第26届大会)
北京
英文
856-859
2007-07-04（万方平台首次上网日期，不代表论文的发表时间）