562 



INDEX 



Law ot conservation of energy for 

 secondary sound pressure waves, 

 186-188 

 Law of motion for sound wave equa- 

 tion, 10 

 Law of similarity for shock waves, 182 

 Layer effect at 24 kc, underwater sound 

 transmission 

 ray acoustics, 56-57 

 theory, 112-114 



thermocline depth, 115-117, 238 

 University of California studies, 114- 

 115 

 Layer effect at 60 kc, underwater sound 



transmission, 117 

 I/ens action of microstructure, sound in- 

 tensity fluctuations, 170-171 

 Listening equipment for wake measure- 

 ments, 484 

 Lloyd Mirror effect in wave acoustics, 



32-33, 299, 301 

 l^ong Island area survey in sonic trans- 

 mission, 154-156 

 Long-range sound channel propagation, 

 211-219 

 deep channels, 213-216 

 experimental results, 216-219 

 introduction, 211-213 

 Loops of stationary sound waves, 33 



Magnetostrictive effect in sound trans- 

 mission, 5, 72 



Mean echo intensity for target strength 

 measurements, 377-378 



Microdispersers for measuring damping 

 constant in sound field, 467 



MIKE bathy thermograms, 93-95 



Motion law for sound wave equation, 10 



Motion pictures of subsurface structure 

 of wakes, 456 



Moving vessels, target strengths, 425- 

 426, 437 



Multiple scattering of sound, 268-269, 

 ,303-304 



NAN bathythermograms, 93-95 



Narrow -band pings, frequency analysis 

 of reverberation, 329-331 



Naval warfare, acoustic wakes, 443-448 



Navy echo ranging 

 see Echo ranging 



Newton's second law of motion for 

 sound wave equation, 10 



NK-1 type shallow depth recorder for 

 acoustic wakes, 455 



Nodes of stationary sound waves, 33 



Noises, sinusoidal sound vibrations, 23 



Nonisothermal water, bottom rever- 

 beration of sound, 321-323 



Nonresonant bubbles, acoustic meas- 

 urements, 476, 477 



Nonspecular reflections of sound, 361- 

 362, 410 



Normal mode theory of sound, 34-38, 

 222-229 

 bottom reflection, 222-224 

 characteristic functions, 35-36 

 dispersion phenomena, 225-228 

 general waves, 36-37 

 intensity of sound, 37-38 

 plane waves, 34-36 

 prediction of rays, 224-225 

 pressure-time records, 228 



OAX transducei-s, 78 



Ocean bottoms, acoustics properties, 



139-141 

 Oceanographic conditions for sound 

 transmission 

 bathythermographs, 76 

 measurements, 243 

 target strengths, 411-413 

 wakes, 492-493 

 Off-beam target strengths, 417-420, 



436-437 

 One-way horizontal transmission loss, 



acoustic wakes, 504-506 

 Optical experiments for target strength 

 measurements, 379-381, 386, 

 410 

 Oscillograms for underwater sound data 

 beam echoes, 415 

 dispersion phenomena, 233-235 

 echo intensities, 377 

 explosive sound, 229-231 

 ground wave phase of disturbance, 



230-233 

 hydrophone output, 74-76 

 pressure-time records, 204-206 

 reverberation data, 278 

 wake measurements, 488-490 

 "Overtaking effect" in shock wave 

 theory, 177, 183 



"Patch size" of acoustic wake, 479 

 Pattern function for intensity of back- 

 ward scattered sound, 254 

 Peak echo intensity in target strength 

 measurements, 373-374, 377- 

 378 

 Perfect fluid, law of forces, 10-1 1 

 Periodmeter for frequency analysis of 



reverberation, 330-331, 339 

 PETER bathythermograms, 93 

 Phase constant in ray acoustics, 41 

 Phase distribution in wave acoustics, 



37-38, 266 

 Photographic Interpretation Center, 

 Anacostia, wake acoustics, 494 



Physical parameters of acoustic wake 

 strength, 514-519 

 echo intensity, 514-515 

 long pulses, 515-516 

 short pulses, 516-519 

 Piezoelectric effect in sound transmis- 

 sion, 5, 72 

 "piling-up" effect in long-range sound 



transmission, 218 

 Pings in reverberation theory 

 coherence, 327-329 

 duration, 334 

 narrow-band, 329-331 

 short pulses, 326 

 surface reverberation, 302 

 volume reverberation, 336 

 wide-band, 332-333 

 Plane waves, sound propagation 

 intensity of sound, 21 

 normal mode theory, 34-36 

 pressure versus fluid velocity, 19-20 

 reflection and refraction, 30-31 

 velocity of sound, 15-17 

 wave equation, 14—15 

 Point method of averaging reverber- 

 ation data, 279-280 

 Point source of sound 



boundary conditions, 33-34 

 equation, 22, 31-32 

 image interference effect, 32-33 

 surface reflection, 32 

 target strength, 353 

 Poisson distribution of fluctuations of 



sound intensity, 326 

 Power level recorders for underwater 

 sound transmission measure- 

 ments, 75 

 Pressure of reflected sound wave, 352- 

 355 

 boundary conditions, 353 

 mathematical analysis, 353-355 

 physical analsyis, 355 

 "Pressure pattern function" of sound 



receiver, 265 

 Pressure versus fluid velocity of sound 



waves, 19-20 

 Pressure waves (secondary) in sound 

 propagation, 186-190 

 oscillatory motion, 186-188 

 spherical symmetry, 188-190 

 Pressure waves (nonlinear) Riemann's 



theory, 178-179 

 Pressure-density properties of a dis- 

 turbed fluid, 11-12 

 Pressure-time curves of shock waves, 



184-186, 204-206, 228 

 Probability coefficients for reverber- 

 ation levels, 328 

 Probability distributions of intensity 

 fluctuations of sound field, 160- 

 164 



