USA As Represented by Secretary of the Navy

David H Shonting

Peter R Hebda

John S Chaves

Foster H Middleton

Jeffrey R Knox

The present invention relates to an instrumentation apparatus for receiving and recording acoustic signals in a range of depths of approximately 5&#x2013;100 m beneath the ocean surface and for providing a set of data outputs from which wind velocity and rainfall rate at the surface may be derived. The apparatus includes an omnidirectional hydrophone for substantially isotropical reception of acoustic energy from its upper hemisphere and for producing an output signal representative of the wind velocity and the rainfall rate at the surface. The apparatus further includes a preamplifier connected to the output of the hydrophone and a circuit for processing the amplified signal and recording data derived therefrom. This circuit includes a microprocessor and a data storage device.

Self-contained ambient noise recorder

An accelerometer calibration system calibrates an accelerometer for use in, for example, an ocean wave environment in which the accelerometer will ergo generally oscillatory acceleration. The accelerometer calibration system includes an simple harmonic motion ('SHM')-derived accelerator and a processor. The SHM-derived accelerator applies an SHM acceleration to the accelerometer. The accelerometer generates an output signal having an amplitude related to the acceleration applied thereto. The processor controls the SHM-derived accelerator to apply selected accelerations to the accelerometer, receives the output signal from the accelerometer and generates a profile relating the accelerations applied by the sinusoidal acceleration means to the amplitude of the output signal. The SHM-derived accelerator applies the SHM acceleration by rotating the accelerometer around a center of rotation, so that the acceleration applied to the accelerometer is a function of the distance of the accelerometer from the center of rotation and the period of rotation. This enables the acceleration to be determined without any need for a reference or control instrument.

System and method for calibrating accelerometer over low (ocean wave)

A submarine deployed sea-state sensor comprises an elongated housing having nose cone and an aft end, the housing having a forward buoyant chamber for receiving an accelerometer. Aft of the buoyant chamber, a damping assembly communication link deployment means and a lifting body are provided. Both the damping assembly and the lifting body are attached to a communication link interconnecting the accelerometer and a submerged platform so that, when the portion of the communication link between the lifting body and the submerged platform becomes taught, the lifting body is pulled from the housing. The damping assembly includes a motion damping body mounted on the buoyant chamber through an extendable telescoping arm. The extension of the arm is controlled by a pressure release spring, so that, when the sensor reaches a selected depth the telescoping arm will extend to project the motion damping body aftwardly.

Submarine deployed sea-state sensor

A submarine deployed sea-state sensor includes an elongated housing having nose cone and an aft end. The housing having a forward buoyant chamber for receiving an accelerometer and for causing the sensor to be buoyed up to the surface, where it will thereafter float in a spar buoy fashion. The housing has, aft of the buoyant chamber, a damping assembly including a longitudinally extending motion damping body, a communication link deployment subassembly and a lifting body, with both the damping assembly and the lifting body attached to a communication link interconnecting the accelerometer and a submerged platform so that, when the subassembly deploys a portion of the communication link between the lifting body and a submerged submarine and this portion of the communication line becomes taught, the lifting body is pulled from the housing and the motion damping body is pulled by the lifting buoy into a distended position from the main portion of the spar buoy. Initially, the motion damping body is telescoped in the housing by a sliding fit between the body and the housing, and the lifting body is releasably joined to the motion damping body by a detent. The distended portion of the motion damping body is defined by a fixed length strap arrangement disposed within the sensor's housing which is connected between the motion damping body and fixed structure located toward the top of the housing.

The present invention relates to an acoustic and environmental monitoring stem which correlates natural phenomena and the sound produced by that phenomena. The system includes a bottom mounted hydrophone for measuring/monitoring ambient sound produced by rainfall, waves and wind with the sensors for measuring/monitoring wave height and direction, wind speed and direction and rainfall rate being located within 100 meters of the sound monitoring hydrophone. The system further includes electrical circuitry for correlating the measured natural phenomena with the measured/monitored sea sound surface.

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Middletown, RI, United States of America

David H Shonting