Light & Engineering Vol. 23, No. 2, pp. 60-63, 2015 Svetotekhnika No. 1, 2015, pp. 40-42 WHITE LIGHT-EMITTING DIODE RADIATORS OF CIRCULAR OPERATION FOR SIGNAL LIGHTS ON BOATS AND FOR WATERWAY NAVIGATION SIGNS Nina A. Galchina, Alexei L. Gofshtein-Gard, Lev M. Kogan, Alexander A. Kolesnikov, Naum P. Soshchin, and Boris K. Flegontov OPTEL Scientifi c–and-practical Center Open Company, Optron Open Company and the Moscow State Academy of Water Transportation, Lyuminofor Research-and-production Company, Fryazino; The Moscow State Academy of Water Transportation» Federal Budgetary Enterprise of the higher vocational training, Moscow E-mail: levkogan@mail.ru ABSTRACT White light-emitting diode radiators of circular operation are developed for signal lights on boats and for navigation signs of waterways. <...> The structure of the radiators is described and their key parameters are given: luminous intensity in the horizontal plane is equal to 95–120 cd (without Fresnel lens), the radiation angle in the vertical plane is 40 о, which secures visibility of the lights when lit from boats or navigation signs at a distance of up to 10 km. Keywords: light emitting diode, light-emitting diode radiator, luminous intensity, correlated chromatic temperature, radiation angle, radiation indicatrix, lens In order to increase navigational safety, equipping boats and navigation warning signs on waterways with signal lights of increased visibility based on energy saving LED radiators is necessary. <...> Three types of white lights are required for boat light alarm system: masthead, aft and circular1. <...> Its bottom part (refractive index n = 1.5–1.6) is an ellipsoid, its big axis is located in the horizontal plane of the radiator passing through the illuminating surface of the phosphor. <...> Eccentricity of the ellipsoid is equal to 0.50–0.55, and the centre is displaced from the radiator centre by 0.35–0.4 of its long semi-axis length. <...> This part of the case has a central cylinder cut, which is topped by a spherical surface, convex towards the phosphor. 1 Masthead light is a white light located in the diameter plane of a boat. <...> It is located so as to be <...>