The sonar equations: definitions, dimensions and units of individual terms

The passive and active sonar equations are reviewed with regard to the definitions of individual terms and their units. It is shown on the one hand that ambiguities exist in conventional definitions that can lead to misinterpretation, and on the other that under special conditions correction terms are needed that are not included in the standard equations. Revised definitions are proposed that remove the need for some of the correction terms and reduce the likelihood of misunderstanding. Particular emphasis is placed on the terms 'propagation loss' and 'source level' for both active and passive sonar. For example, the effect on changes in impedance between the source and receiver of the sound is considered in the case of passive sonar, and between the source, receiver and scatterer of sound in the case of active sonar.

[1]  Marshall V. Hall.  DIMENSIONS AND UNITS OF UNDERWATER ACOUSTIC PARAMETERS , 1995 .

[2]  B. Smith,et al.  Underwater Acoustics , 1971, Nature.

[3]  A single-scattering correction for large contrasts in elastic layers. , 2007, The Journal of the Acoustical Society of America.

[4]  Mario Zampolli,et al.  Parabolic equation solution of seismo-acoustics problems involving variations in bathymetry and sediment thickness. , 2008, The Journal of the Acoustical Society of America.

[5]  Simulations of large acoustic scintillations in the straits of Florida. , 2006, The Journal of the Acoustical Society of America.

[6]  W. Kuperman,et al.  Sound propagation in a wedge‐shaped ocean with a penetrable bottom , 1980 .

[7]  M. Ainslie.  The sonar equation and the definitions of propagation loss. , 2004, The Journal of the Acoustical Society of America.

[8]  P ? ? ? ? ? ? ? % ? ? ? ? , 1991 .

[9]  Michael A. Ainslie,et al.  Underwater radiated noise due to the piling for the Q7 Offshore Wind Park , 2008 .

[10]  Steven G Kargl,et al.  Effective medium approach to linear acoustics in bubbly liquids. , 2002, The Journal of the Acoustical Society of America.

[11]  Michael B. Porter,et al.  Computational Ocean Acoustics , 1994 .

[12]  Joseph F Lingevitch,et al.  A two-way parabolic equation that accounts for multiple scattering. , 2002, The Journal of the Acoustical Society of America.

[13]  R. Urick.  Generalized Form of the Sonar Equations , 1962 .

[14]  F. R. DiNapoli,et al.  Theoretical and numerical Green’s function field solution in a plane multilayered medium , 1980 .

[15]  Nobuyuki Endoh,et al.  Numerical Analysis of Underwater Sound Propagation in Shallow Water Calculated by Finite Difference Time Domain Method with Parallel Processing , 2005 .

[16]  S.P. Robinson,et al.  The measurement of the underwater radiated noise from marine piling including characterisation of a "soft start" period , 2007, OCEANS 2007 - Europe.

[17]  Robert J. Urick,et al.  Principles of underwater sound , 1975 .

[18]  J. W. Horton.  Fundamentals of Sonar , 1959 .

[19]  Robert J. Urick,et al.  Principles of underwater sound for engineers , 1967 .

[20]  W. Melville,et al.  SOUND-SPEED MEASUREMENTS NEAR THE OCEAN SURFACE , 1994 .

[21]  C. L. Morfey.  Dictionary of Acoustics , 2000 .

[22]  M. Ewing,et al.  Propagation of sound in the ocean , 1948 .

[23]  Finn B. Jensen,et al.  Numerical solutions of range-dependent benchmark problems in ocean acoustics , 1990 .

[24]  Joseph E. Murphy,et al.  A finite-element model for ocean acoustic propagation and scattering , 1989 .