| 摘要 |
FIELD: measurement of speed of ships, hovercraft and seaplanes at landing approach. ^ SUBSTANCE: radiation beam at preset diameter 2a is directed to surface not disturbed by ship. Reflected luminous radiation is received in field of view angle making it possible to record mirror areas on surface wave. During reception, angular filtration of reflected radiation is performed and average duration of reflected radiation pulses tau is found. Ship's speed V is found from the following formula: V=2a/tau. Device proposed for realization of this method includes laser radiator with modulator, optical system, receiving optical system, photodetector, buffer stage, resonance amplifier, detector, standard amplitude pulse shaper, coincidence circuit, frequency meter and display unit. Receiving objective is made in form of Fresnel lens. Aperture diaphragm is made in form of slit diaphragm. Photodetector is made in form of photodiode. Detector is made in form of synchronous detector. ^ EFFECT: enhanced accuracy and reliability of measurement of ship's speed; facilitated procedure of information processing. ^ 3 cl, 1 dwg |
