METHOD OF MEASURING RANGE UNDER WATER AT ARBITRARY POSITION IN HORIZONTAL PLANE LONGITUDINAL AXIS OF RECEIVING FRAME MAGNETIC ANTENNA Russian patent published in 2020 - IPC G01S15/08 

FIELD: measurement.

SUBSTANCE: method of measuring range under water at arbitrary position in horizontal plane longitudinal axis of receiving frame magnetic antenna relates to the field of radio engineering equipment for measuring distances and can be used, for example, for measurement of short distances in local navigation systems when controlling movement of underwater objects. As before, two channels of information transfer are used, both of which are suitable for transmitting signals under water. First channel uses inductive coupling of frame magnetic antennae. By means of this channel continuous oscillations with known phase shift are formed at both ends of the measurement route. Acoustic waves are used in the other channel. Actually, the phase shift of acoustic waves is an information parameter for determining the distance. Novelty in the method of measuring range is using simultaneously two transmitting frame magnetic antennae, the longitudinal axes of which are mutually perpendicular in the horizontal plane. Low-frequency signals shifted relative to each other by 90° are transmitted to the antennae. Thus, the antennae form an alternating magnetic field of circular polarization in the horizontal plane. Signal level induced in the receiving frame magnetic antenna does not depend on the orientation of its longitudinal axis in the horizontal plane and always has the same value. Only the value of the initial phase of the signal is changed when the position of the longitudinal axis of the receiving frame magnetic antenna changes. However, at subsequent change of phase differences, said initial phase is mutually subtracted, and range is determined uniquely at any position of longitudinal axis of receiving frame magnetic antenna.

EFFECT: method for measuring range under water is proposed.

1 cl, 1 dwg