Ship movement measurement

Claim 1

Method for determining the movement of a ship comprising: measuring the longitudinal and lateral velocity of the ship at an aeration-free location at the bottom of the ship; measuring the rate-of-turn of the ship about its vertical axis; generating signals representing each of the measured values; visually displaying the magnitude of the signal representing the longitudinal velocity as a vertical displacement of a horizontal line from a neutral horizontal axis; visually displaying the signal representing the lateral velocity as a horizontal displacement of a vertical line from a neutral vertical axis, said displays of longitudinal and lateral velocity being superimposed and having the same horizontal and vertical scales; visually displaying the magnitude of the signal representing the rate-of-turn; and superimposing on the display of longitudinal and lateral velocity a monogram for indicating the drift angle of the vessel resulting from the longitudinal and lateral velocities.

Claim 4

A system for determining the movement of a ship comprising: a velocity transudcer mounted on the bottom of the ship, said transducer having at least two active elements arranged to detect the lateral and longitudinal velocity of the ship and provide signals related to the detected velocities; a rate-of-turn transducer mounted on the ship to detect the rate-of-turn of the ship and provide a signal related to the detected rate-of-turn; circuit means, said signals related to the lateral velocity and rate-of-turn being supplied to said circuit means, said circuit means supplying an output signal related to the algebraic sum of the input signals; and display means, said algebraic sum, lateral and longitudinal velocity signals being supplied to said display means, said display means providing a graphic display of said signals representative of the movement of the ship.

Claim 5

A system for determining the movement of a ship comprising: a velocity transudcer mounted on the bottom of the ship, said transducer having at least two active elements arranged to detect the lateral and longitudinal velocity of the ship and provide signals related to the detected velocities; a rate-of-turn transducer mounted on the ship to detect the rate-of-turn of the ship and provide a signal related to the detected rate-of-turn; circuit means, said signals related to the lateral velocity and rate-of-turn being supplied to said circuit means, said circuit means supplying an output signal related to the algebraic sum of the input signals; and display means, said algebraic sum, lateral and longitudinal velocity signals being supplied to said display means, said display means providing a graphic display of said signals representative of the movement of the ship.