Acoustic Transducer Design Application of Advanced Acoustic Technology
- Slides: 13
Acoustic Transducer Design: Application of Advanced Acoustic Technology to Oceanographic Measurements Dezhang Chu Woods Hole Oceanographic Institution, MA 02543
Transducer Design: ? Physical Process Range? Sample Volume? ? Targets Biological Process
Active Sonar Equation SL = Source Level (d. B re 1 m. Pa @ 1 m) TL = Transmission Loss ( 40 log r + 2 ar) NL = Noise Level (d. B) DIR= Receiving Directivity ( ) TS = Target strength (d. B) SV = Volume Backscattering Strength (d. B) V = Insonified Sample Volume (m 3) Example: Typical parameters for a Simrad EK 500, 120 k. Hz transducer at T = 5 o C TS = -70 d. B, r = 67 m SNR = 10 d. B FREQUENCY (Hz)
Characteristics of Scattering Targets siphonophore fish pteropod T-microstructure (Intense ) euphausiid copepod T-microstructure (Background )
Fluid Sphere - ka Resonance Scattering Geometric Scattering Rayleigh Scattering
Application Objective: • Detection – Resonance frequency, geometric scattering region ( ) • Classification – two or more frequencies, or broadband signals ( ) Resonance Scattering Geometric Scattering Rayleigh Scattering
Angular Resolution - Beampattern main lobe side lobes Disk
Linear Array (more complicated system) b Aperture Angular Resolution: Field of View Array Gain:
beampattern of individual element Linear array grating lobe main lobe
Lost City 2003 (Kelley, Karson, Yoerger, Bradley)
Range Resolution Narrow-band: Broadband: (Chirp) Pulse Compression
Sidelobe Reduction mechanical shading Chebyshev Weighting slightly broader main lobe electronic shading
Objective Detection Classification Geometry Application Range Sample Volume SNR Frequency Bandwidth Beampattern Spatial Resolution Array Parameters etc. Sensor Parameters Target Physical/Biological Charactristics
- Resistive position transducer
- Application of acoustic emission testing
- Acoustic era of recording technology
- Lecture hall acoustic design
- Advanced pedagogy and application of ict book pdf
- Advanced application and middleware security
- Introduction to transducers
- Example of active transducer
- Turbulence
- Zink common compensatory pattern
- Ott pls-c
- Piezoelectric transducer ppt
- Acceleration transducer
- Definition of sensor and transducer