Patent ID: 11879971
Assignee: TELEDYNE INSTRUMENTS, INC.
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 15:
16. An underwater active sonar system, comprising:
a plurality of parametric array projectors configured to project a plurality of acoustic beams in different directions;
a plurality of hydrophone sub-arrays configured to receive and spatially demodulate a spatiotemporal pattern of backscattered acoustic signals corresponding to echoes of the projected acoustic beams from a plurality of scatterers in the water while preserving the relative phase relationship of the backscattered acoustic signals; and
a processor configured to separate received backscattered acoustic signals backscattered from different ones of the projected acoustic beams, linearly combine the acoustic signals received over each of the hydrophone sub-arrays, and measure vehicle velocity and/or water velocity components based on the linearly combined acoustic signals,
wherein the parametric array projectors project frequencies that interact non-linearly, and
wherein the processor is configured to use a phase of a cross-correlation function at or near a lag equal to a Doppler-shifted pulse repetition interval in multiple acoustic beams to measure velocity.