The impacts of light pollution become increasingly serious to people in Taiwan and the petition cases increased recently. In this project, we study dynamic characteristics of the LED display board and the LED combo, develop its measurement method drafts, and propose the scintillation light pollution prevention countermeasures according to conditions of Taiwan. In this project, we collect international regulations and complete three regulations and guidelines summary translation analysis, and completed a comprehensive analysis of domestic and international regulation; after the influence factor analysis, we selected luminance, vertical illuminance, glare and flicker as key light pollution factors; complete measurement procedure drafts of luminance, vertical illuminance, glare and flicker for the motion pictures of LED display board, respectively; complete Hsinchu and Kaohsiung on-site measurements, include 9 luminance measurements, 5 dynamic luminance monitoring measurements, 2 reflected luminance monitoring measurements, 9 vertical illuminance measurements, 2 vertical illuminance monitoring measurements, 2 reflected vertical illumination monitoring measurements, 10 horizontal illuminance monitoring measurements, 2 reflected horizontal illumination monitoring measurements; complete 23 glare and 23 flicker measurements of LED combo; assist Taiwan EPA (Environmental Protection Administration) to complete a draft of light pollution prevention Act.
Related implementation results of this project are as follows:
1. Dynamic luminance measurement of light source: according to the current field test results of LED display boards, the proposed measurement method might have the higher probability to get the maximum luminance of LED display board, which using a luminance meter point at selected test point for a period of time to monitor the luminance of LED display board.
2. Dynamic illuminance measurement of light source: according to the current field test results of LED display boards, the proposed measurement method is using an illuminance meter face to the light source for a period of time to monitor the vertical illuminance.
3. Glare and flicker measurement methods: we recommend the use of dynamic imaging luminance measurement device (DILMD) with video mode to record the test scene luminance distribution variations.
4. Evaluation glare and flicker empirical formula: with the ergonomic experiment data, the temporal unified glare rating (UGR(t)) and the temporal flicker index (FI(t)) we have a dynamic comfort rating as following: .
5. LED combo evaluation: based on glare and flicker measurement methods and impact evaluation of the empirical formula to calculate five status of LED combo, include synchronous flashing, radial stack, argument stack, radial scan, and argument scan, the corresponding smallest comfort ratings of these five statuses are approximately 3, 4, 4.6, 4.9, and 6.7, respectively. This result is consistent with the viewing perceived trend; in other words, argument scan is most comfortable, synchronous flashing is most uncomfortable.
6. The sun reflected luminance measurements, because the huge reflected luminance variation, the current proposal is using a luminance meter to monitor the luminance of the selected test point.
7. Complete the light pollution protection draft ACT, and a proposal of light pollution control according the light source types, measurement parameters, and light source utilization behaviors, respectively.