People are subject to the effects of light pollution is become increasingly serious, petition cases also increased, based on the characteristics of conditions of our country, we investigation and analysis of the degree of light pollution types of human comfort sensation, and proposed a proposal of light pollution control strategy.
In this project, we study the light pollution issue, which include the study on 10 literatures and regulations, analyze the petitions of citizens and practice the ergonomic experiments of LED screen on the parameters, such as color saturation, glare and flicker, etc. We also complete an expert advisory meeting and complete 64 physical test results of glare and flicker impact of LED screen. Based on the above study, we got a proposal of light pollution control strategy.
In study the color saturation and glare evaluation experiments of LED screen using 9 color images, we find out the image quality of LED screen under test will affect the de Bore glare evaluation score. The averaged de Bore scores of female and male are 3.93 and 4.66, respectively. The averaged de Bore scores of elder people (above 40 years old) and younger people (under 40 years old) are 4.54 and 4.05, respectively. These four averaged scores are between ~4 and 5, which mean they are between just acceptable (de Bore score 5) and disturbing (de Bore score 3). There are 20 objects involve in this study, and related collected data are 3240.
In the flicker evaluation experiments, we show simple white block on LED screen. We find out, the averaged de Bore score of elder people (3.41±1.47) is less than younger people (4.67±0.64). This result is conflict to result from color saturation and glare experiments, which might due to the basic characteristics of test patterns of these two experiments, are different significantly, which might be due to static color images used in color saturation and glare experiment, while flickering white block test pattern used in this experiment. The corresponding averaged de Bore score of 32 Hz is 4. There are 25 objects involve in this study, and related collected data are 1275.
For the control strategy of light pollution, we got a luminance suggestion table of respective glare evaluation score from the color saturation and glare evaluation experiments. Base on this table, we suggest the maximum average luminance can be 618 cd/m2(de Bore score 5) or 1590 cd/m2(de Bore score 4). These luminance values can be used as a reference of the management strategy set in the future. Hence, we suggest to reduce the color saturation and luminance without scarify image quality of LED screen. This suggestion will reduce the glare and energy consumption and electricity cost. This suggestion will also benefit to the citizens and the environments.
According to above results, we suggest to study the interaction between the parameters, such as background luminance, image quality, luminance and flashing frequency of LED screen, in the near future.