ENVIRONMENTAL 

 FACTORS 



TRANSMISSION 

 FACTORS 



-SPREADING 



-ABSORPTION- 



-REFLECTION 



1-FLUCTUATION 



£ 



REVERBERATION 

 (SCATTERING) h 

 FACTORS 



■BOUNDARY 



-VOLUME- 



LOW 

 I — FREOUENCY- 

 (>500Hz) 



AMBIENT 

 NOISE 



HIGH 



FREOUENCY- 



(>500Hz) 



SOUND VELOCITY 

 STRUCTURE 



TIME STRETCHING 

 VISCOSITY 

 - Mg SO4 

 •FREO <5KHz 

 SEA SURFACE 



SEA BOTTOM 



INOMOGENITIES 



MICROSTRUCTURE 



SEA SURFACE 

 SEA BOTTOM 

 DSL 

 ER 



OTHE 



-TIDAL CURRENTS 



TURBULENCE 



-SEISMIC DISTURBANCE 

 SHIP TRAFFIC 



RAIN 



-BIOLOGICAL NOISE 

 -SURFACE WAVES 



-SURFACE Vl/AVES 



THERMAL NOISE 



RAIN 



-BIOLOGICAL NOISE 



Figure 16, 



86 



