Practical experiences with inertial type underwater acoustic intensity probes

McConnell, James A.

doi:10.1109/oceans.2002.1191925

Cited by 5 publications

(6 citation statements)

References 8 publications

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“…However, studies on acoustically small bodies (when compared to the wavelength) suspended in an elastic medium provide the foundation for using accelerometers for the present application. Such bodies directly respond to the particle motion and if an accelerometer is embedded inside them, it will move in consonance with the body and thus provide an estimate of particle velocity [5]. The particle velocity of a small sphere, us, of radius, a, and density, Ps , immersed in an infinite viscous fluid medium having density, Po, and viscosity, 7], when ensonified with a plane traveling wave having a velocity, uo' is given by the following relation,…”

Section: V Ector S Ensor-o Verviewmentioning

confidence: 99%

“…The array manifold of the accelerometer based vector sensor is given as, (5) where, the subscript, k, denotes the steering vector corresponding to the f(h acoustic wave incident on the vector sensor, tPk is its elevation angle and <Pk is the corresponding angle in the azimuthal plane. The vector on the right most of the relation describes the direction cosines.…”

Section: D Irection Of a Rrival Estimationmentioning

confidence: 99%

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Source Ranging and Direction of Arrival Estimation using accelerometer based implementation of prototype Acoustic Vector Sensor

Kalgan

Bahl

Kumar

2015

2015 IEEE Underwater Technology (UT)

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Acoustic emissions from underwater sources are used to detect, locate, and track targets by passive surveillance sensors. The "vector" sensors measure the scalar pressure as well as the orthogonal components of particle velocity and offer distinct advantages over the traditional solution of array of hydrophones due to their smaller size and frequency independent performance over the frequency range specified for constituent elements. This paper presents studies on an in-house implemented prototype vector sensor employing tri-axial accelerometer as constituent element. The tests undertaken include Direction of Arrival (DoA) estimation and application of modified Fast Orthogonal Search technique on a single Vector Sensor for improvement in spectral resolution. We also propose a configuration involving just two Vector Sensors (composed solely of accelerometers) that offers ease of design and obviates the requirement of a pressure sensor in setup for obtaining DoA estimate while also providing range to the source.

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Section: V Ector S Ensor-o Verviewmentioning

confidence: 99%

Section: D Irection Of a Rrival Estimationmentioning

confidence: 99%

Source Ranging and Direction of Arrival Estimation using accelerometer based implementation of prototype Acoustic Vector Sensor

Kalgan

Bahl

Kumar

2015

2015 IEEE Underwater Technology (UT)

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“…[1][2][3][4][5] There are two main components to a p-a underwater vector sensor: a pressure sensor and a particle velocity sensor. A p-a probe with high acceleration sensitivity should be nearly neutrally buoyant in water.…”

Section: Vector Sensor Designmentioning

confidence: 99%

“…For more detail on SWCs, see McConnell. 5 The SWC used in this study was located at Applied Physical Sciences Corporation (APSC), and the calibration was performed by Dr. James McConnell. The SWC at APSC is driven by a J9 piston-type acoustic source and the duct is acrylic.…”

Section: Calibrationmentioning

confidence: 99%

Design and implementation of a shielded underwater vector sensor for laboratory environments

Barnard¹,

Hambric²

2011

The Journal of the Acoustical Society of America

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Underwater acoustic vector sensors, for measuring acoustic intensity, are typically used in open water where electromagnetic interference (EMI) is generally not a contributor to overall background noise. However, vector sensors are also useful in a laboratory setting where EMI can be a limiting factor at low frequencies. An underwater vector sensor is designed and built with specific care for EMI immunity. The sensor, and associated signal processing, is shown to reduce background noise at EMI frequencies by 10–50 dB and 10–20 dB across the entire frequency bandwidth, as compared to an identical unshielded vector sensor.

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“…Sensing the motion of the medium has been studied for decades by various research groups [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. Leslie et al [ 1 ] described the operation of hydrophones enclosed within a spherical housing.…”

Section: Introductionmentioning

confidence: 99%

MEMS Underwater Directional Acoustic Sensor in Near Neutral Buoyancy Configuration

Alves

Park

McCarty

et al. 2022

Sensors

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A MEMS directional acoustic sensor housed in an air cavity and operated underwater in a near-neutral buoyancy configuration is demonstrated. The sensor consists of two wings connected by a bridge and attached to a substrate by two centrally mounted torsional legs. The frequency response showed two resonant peaks corresponding to a rocking mode (wings moving in opposite directions) and a bending mode (wings moving in the same direction). Initial tests of the sensor using a shaker table showed that the response is highly dependent on the vibration direction. In air, the sensor showed a maximum sensitivity of about 95 mV/Pa with a cosine directional response. Underwater, the maximum sensitivity was about 37 mV/Pa with a similar cosine directional response. The measured maximum SNR was about 38 dB for a signal generated by a sound stimulus of 1 Pa when the sensor is operated near the bending resonance. The results indicate that this type of MEMS sensor can be operated in a near-neutral buoyant configuration and achieve a good directional response.

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Practical experiences with inertial type underwater acoustic intensity probes

Cited by 5 publications

References 8 publications

Source Ranging and Direction of Arrival Estimation using accelerometer based implementation of prototype Acoustic Vector Sensor

Source Ranging and Direction of Arrival Estimation using accelerometer based implementation of prototype Acoustic Vector Sensor

Design and implementation of a shielded underwater vector sensor for laboratory environments

MEMS Underwater Directional Acoustic Sensor in Near Neutral Buoyancy Configuration

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