Screening of light environment evaluation indices for ship night navigation

In order to objectively and comprehensively evaluate the light environmental quality of the ship navigation at night and ensure the safety of the ship navigation at night, the concept and source of the light pollution at sea were analyzed, the light environment evaluation indices of the ship navigation at night were proposed, which should follow the principle of "dominance, operability and wide coverage".On the basis of the principle for selecting indices, the theoretics of optics, chromaticity and system engineering were used, 19 evaluation indices were selected from 3 aspects including navigator's visual performance, ship collision avoidance and light environment condition of ship night navigation, and the light environment evaluation system at sea was established; furthermore, the evaluation criteria of the brightness of background light, the chromaticity of background light, the glare of pollution light and the flickering degree of pollution light were given in the navigation light environment condition, which laid foundation for the measurement and evaluation of light environment of ship night navigation.