Underwater Acoustics and Sonar Systems

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Underwater Acoustics and Sonar Fundamentals

A series of two, three-day on-site courses intended for engineers and other technical personnel and managers who have a work-related need to understand basic underwater acoustics and sonar system concepts. This is an introductory course and participants need not have any prior knowledge of sound or vibration, underwater phenomena, or signal processing.  These courses  can serve as part of a new employees’ orientation. Emphasis is placed on illustrating phenomena and principles through appropriate applications, in-class demonstrations, and worked-out examples. Topics are presented with an emphasis on concepts, not on mathematics.

4A.  Underwater Acoustics I & Passive and Active Sonar (3-Days)

    Introductory Concepts
  • Historical background
  • Sonar systems and platforms
  • ASW analysis and strategies

    • Basic Sound and Vibration
  • Sound in fluids and solids
  • Waveforms and frequency analysis
  • Sound energy, power, intensity, and pressure
  • Decibel (dB) scales and references

    • Basic Underwater Acoustics
  • Sound speed profiles  (SSP)
  • Cavitation considerations
  • Ambient noise: frequency and directional characteristics
  • Self-noise issues
  • Propagation loss: spreading and absorption

    • Passive Sonar Systems
  • Passive sonar equation and signal processing
  • Radiated noise levels and explosive charges
  • Octave and narrow band analysis
  • Target detection threshold (DT)  and ROC curves
  • Figure of merit and range assessments

    • Active Sonar Systems
  • Active sonar equation and signal processing
  • Reverberation noise: Volume, surface, and bottom
  • Active pings:  Pure tones (PTL and PTS) and FM
  • Range – Doppler ambiguity
  • Doppler effects on target returns
  • Own Doppler nullification (ODN)

4B.  Underwater Acoustics II & Select Sonar Systems (3-Days)

    Underwater Sound Propagation
  • Sound reflection and refraction
  • Ray acoustics and convergence zones (CZ)
  • Sound channels: surface ducts, SOFAR, RAP
  • Surface effects: scattering, Doppler, Lloyd mirror
  • Bottom effects: scattering, refraction, lateral waves

    • Shallow Water Acoustics
  • Littoral environmental factors
  • Ambient noise
  • Multipath effects: signal stretch
  • Shallow water waveguides: lossy normal modes
  • Internal waves and currents

    • Sonar Transducers and Arrays
  • Transducer elements: sensitivity and directionality
  • Sonar arrays: linear, planar, cylindrical, and spherical
  • Array processing: beamforming, steering, bearing angle

    • Target Characteristics
  • Target construction: single and double hulls
  • Target strength measurements
  • Mono-static and multi-static target scattering
  • Hull geometry and structure effects
  • Echo formation and anechoic coatings

    • Selected Underwater Acoustics and Sonar Systems
  • Other topics of interest to course participants
Learning Options:
  • On-site tailored instruction: Each course, two-day on-site class
  • On-line mentoring: To be selected
Course Materials:
  • Each student receives a copy of the instructor's course notes.
  • Optional texbooks are available at an additional charge




















 To register for a class, or if you have any questions about our offerings, please contact Alan Stuart, Ph.D