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US 2012/0057430 A1Published application
Multi-component, acoustic-wave sensor and methods
AssigneeION Geophysical Corporation
InventorsRobert E. Rouquette, Andre' W. Olivier, Dale J. Lambert
Life of this patent
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Abstract
A multi-component sensor of a fluid-borne acoustic wave that senses pressure and up to three orthogonal particle motion components. The sensor is unresponsive to motion of the sensor mount. Furthermore, the sensor is substantially unresponsive to the turbulent flow of the acoustic medium past the sensor.
Claims68
An underwater acoustic-wave particle-motion sensor comprising:
- a rigid body having a periphery around which an underwater acoustic wave diffracts;
- a diffraction-pressure-gradient acoustic-wave particle-motion sensor coupled to the rigid body to sense the diffracted acoustic wave and further producing a first sensor output signal that responds to acoustic-wave particle motion and to rigid-body motion;
- and
- a rigid-body motion sensor attached to the rigid body producing a second sensor output signal that corresponds almost entirely to rigid-body motion.
1 more element
An underwater sensor system comprising:
- an underwater cable;
- a rigid body coupled to the underwater cable and having a periphery around which an underwater acoustic wave diffracts;
- a diffraction-pressure-gradient acoustic-wave particle-motion sensor mounted in the rigid body and producing a first sensor output signal that responds to acoustic-wave particle motion and to rigid-body motion;
- a rigid-body motion sensor mechanically coupled to the rigid body and producing a second sensor output signal that corresponds almost entirely to rigid-body motion.
1 more element
An underwater diffraction-pressure-gradient sensor comprising:
- a rigid body having a periphery surrounding a central longitudinal axis and a first set of recesses circumferentially spaced around and opening onto the periphery and a second set of recesses circumferentially spaced around the periphery and longitudinally offset from the first set;
- a plurality of pressure sensors, each of the pressure sensors residing in one of the recesses of the first and second sets;
- wherein the rigid body diffracts underwater acoustic waves around the periphery of the rigid body.
A method for determining the response to acoustic waves in a fluid medium, comprising:
- acquiring acoustic-pressure signals from a plurality of pressure sensors mounted at the periphery of a rigid body disposed in a fluid medium and diffracting acoustic waves around the periphery;
- producing pressure-gradient signals from the acoustic-pressure signals that include responses to acoustic waves, responses due to motion of the rigid body, and responses due to the flow of the fluid medium past the pressure sensors in the rigid body;
- acquiring rigid-body motion signals with a motion sensor coupled to the rigid body;
- producing motion sensor signals that include responses due to motion of the rigid body and responses due to the flow of the fluid medium past the motion sensor;
- and
- combining the pressure-gradient and motion sensor signals to produce an output signal that includes the response to acoustic waves and is substantially independent of signals corresponding to the motion of the rigid body or to the flow of the fluid medium past the pressure and motion sensors.
3 more elements
An underwater sensor comprising:
- a pressure-gradient acoustic-wave particle-motion sensor including a plurality of acoustic-wave pressure sensors disposed at fixed relative positions, the acoustic-wave pressure sensors having individual frequency responses combined to produce a pressure-gradient frequency response,
- wherein the individual frequency responses of the acoustic-wave pressure sensors are matched closely enough over an operating-frequency range to attenuate the pressure-gradient frequency response to acoustic-wave pressure below the pressure-gradient frequency response to acoustic-wave particle motion.
An underwater sensor comprising:
- a rigid mounting body having an outer periphery and recesses at regularly spaced positions opening onto the periphery;
- a plurality of pressure sensors received in the recesses at the regularly spaced positions to form a pressure-gradient sensor, wherein the frequency responses of the pressure sensors are matched in magnitude and phase over an operating-frequency range.
A method for making an underwater pressure-gradient acoustic-wave sensor having the performance capabilities of a particle-motion sensor, comprising:
- acquiring first and second pressure signals from first and second acoustic-wave pressure sensors attached to a rigid body at spaced apart locations;
- producing a pressure-gradient signal from the difference of the first and second pressure signals;
- and
- matching the frequency responses of the first and second pressure signals over an operating-frequency range to attenuate in the pressure-gradient signal the response to acoustic-wave pressure below the response to acoustic-wave particle motion.
1 more element
Dependencies are inferred from the claim text.