INDEX 



565 



reflectivity, 353-355, 361, 386 

 San Diego, 379 

 scattering, 481-482 

 spherical, 348-350, 434 

 summary, 434-435 

 surface vessels, 422-424 

 transmission loss, 345-347, 369-374 

 uses, 343-344 

 wakes, 512-513 

 wavelength effects, 386-387 

 Targets, echo-ranging, 84 

 Taylor Model Basin, sonic transmission 



experiments, 188, 456 

 Temperature gradients in the ocean 

 introduction, 3 



microstructure, 90-92, 482-183 

 ray diagrams, 89-90 

 refraction, 312-313 

 60 kc transmission, 135 

 surface effects, 239, 296-297 

 velocity, 15-17 

 wake structure, 441, 479-480 

 Temperature gradients (negative) in 

 the ocean 

 attenuation coefficient, 124-125 

 ray theory, 61-62 

 shadow zones, 120-122, 125-129 

 sharp gradients, 120-129 

 60 kc transmission, 135 

 sound channels, 131-133 

 transmission anomalies, 118-120, 



122-123 

 weak gradients, 129-133 

 Temperature-depth patterns, ray dia- 

 grams, 60-63 

 Thermal microstructure for sound in- 

 tensity fluctuations, 169-171 

 Thermal wakes, sound transmission, 



441, 479-480, 496 

 Thermocline, sound transmission 

 see also Isothermal water, sound 



transmission 

 below isothermal layer, 238 

 ray theory, 61 



submarine target strengths, 411-413 

 temperature gradients, 89 

 Thermocouple recorder for sound ve- 

 locity measurements, 17 

 Thermod3fnamic law for absorption of 



sound, 464 

 Thickness of acoustic wakes, 498-500 

 Thickness of shock wave fronts, 177, 

 182-184 

 dissipation of energy, 183-184 

 Hugoniot equation, 184 

 Riemann overtaking effect, 183 

 summary, 177 

 "Time of arrival" of bottom-reflected 



sound pulses, 221-222 

 "Time of rise" data for short-range 

 sound propagation, 193 



Time patterns of sound intensity 

 fluctuations, 164-167 



"hidden periodicities", 166-167 



self-correlation coefficient, 164-166 

 Training errors in echo-ranging on 



wakes, 491-492 

 Transducers for acoustic measurements 



calibration, 78 



directivity, 522 



EBI-1;276 



JK, 276 



QB-crystal, 275-276 



QCH-3; 273-275, 290-292 



reverberation intensities, 272-273, 277 



target strengths, 429-430 



wakes, 492 

 Transmission anomaly in underwater 

 sound 



see also Attenuation of sound 



average, 122-123, 131-133 



bottom scattering, 319-321 



definition, 70-71, 237 



image effect, 95-97 



isothermal water, 100-104 



ray theory, 53-54, 58-59, 67-68 



supersonic, 147-150 



target strength, 369-371 



temperature gradients, 118-120 

 Transmission loss measurements 



attenuation, 373, 503-504 



background, 3-4, 69-71 



bubble theory, 469-470 



echo runs, 84-85 



equipment, 76-78 



inadequacy, 372 



methods, 78-80 



observed echo ranges, 85 



oceanographic factors, 492-493 



one-way horizontal transmission, 504- 

 506 



propagation along wakes, 509-510 



propeller wakes, 510-511 



receivers, 73-76 



sources, 72-74 



summary, 71-72 



supersonic frequencies, 80-84 



surface reflections, 373-374 



target strengths, 369-372, 411-413, 

 43^431 



two-way horizontal transmission, 

 506-507 



two-way vertical transmission, 507- 

 509 



variation, 107-108 



wakes, 345-347, 504 

 Transmission of sound, deep-water 



absorption, 97-104 



attenuation coefficient, 103-107 



bathythermograms, 92-95 



characteristics, 86-89 



echo-ranging trials, 109-110 



image effect, 95-97 



introduction, 86 



isothermal water, 95, 238-239 



layer effect, 112-117 



long-range experiments, 216-219 



negative temperature gradients, 118- 



120 

 scattered sound in shadow zone, 125- 



129 

 sharp temperature gradients, 120- 



125, 239 

 short-range, 108-109 

 60 kc transmission, 135 

 sound channels, 133-135, 239-240 

 thermocline, 110-111, 238 

 transmission loss, 107-108 

 variabiUty of vertical temperature 



gradients, 90-92 

 vertical temperature structure, 89-90 

 weak temperature gradients, 129- 



133, 239 

 Transmission of sound, shallow-water 

 dispersion phenomena, 228-229 

 experiments, 229-235 

 reflection coefficient, 140-141 

 sea bottoms, 137-140 

 sonic, 154-157 

 summary, 240-241 

 supersonic, 139-140 

 24 kc transmission, 141-143 

 velocity gradients, 142-150 

 wind force, 152-154 

 Transmitted wave, 30 

 Triangulation in long-range sound 



transmission, 219 

 Triplane in echo ranging, 84 

 Turbulence parameter for acoustic 



wakes, 452^55 

 Two-way horizontal transmission loss 



in acoustic wakes, 506-507 



Underwater sound transmission, 236- 

 244 



see also Fluctuations in sound trans- 

 mission; Transmission of sound, 

 deep-water; Transmission of 

 sound, shallow-water 



recommendations for future research, 

 241-244 



summary of definitions, 236-238 



Variability of echo intensity, 374-378 

 "Variance of ampUtudes" for sound in- 

 tensity measurements, 237 

 Variations in sound transmission 



short-range propagation, 211 



summary, 241 



transmission loss, 71, 107-108 

 Velocity of sound in water 



bubble theory, 473^74 



microstructure, 482 



