DEVICE FOR MEASURING SPEED OF MOVING BODY.

摘要

A device for measuring the speed of a moving body such as a ship, a mass of water or the like. The device comprises a means (11, 12, 26, 28) for measuring the ground speed of the ship; a first device for measuring the speed of the moving body which measures the phase difference between a reference signal and an echo signal caused by a transmitted ultrasonic signal and includes a Doppler shift frequency (26), performs a predetermined Fourier-transform of the obtained phase difference data, calculates a log speed of the ship from the obtained Fourier spectrum (28), and calculates a tide speed from the obtained ground speed and the obtained log speed of the ship (28); a second device for measuring the speed of the moving body which measures a period every pulse included in the received echo signal (26), calculates the log speed of the ship from the inverse number of the period and the Doppler shift frequency (28), and calculates the tide at the depth at which the echo signal is generated from the ground speed and the log speed of the ship (28); and a selecting means (10) for selecting either of the first and second devices to operate the selected one.