METHOD OF MEASURING SPEED OF MOTION OF SHIP RELATIVELY THE WATER SURFACE AND DEVICE FOR REALIZATION Russian patent published in 1994 - IPC

FIELD: navigation. SUBSTANCE: laser radiation before being directed onto water surface is modulated for intensity. The radiation is directed with preset radius of light beam vertically to disturbed surface. When receiving reflected radiation the angular filtration is performed. Duration of reflected signal is measured. Average mean of pulse duration is determined and speed of the ship relatively the water surface is determined from the equation given in the description of the invention. Objective of the device is made in form of Fresnel lens. Diameter of the lens is determined by the relation given in the description. EFFECT: improved precision of measurement. 2 cl, 1 dwg