Table 1 



Calculated Detectiofi Ranges for Platform SSD-1 



Platform Data: Semi-submersible, drilling, tv/in hulls, 26 ft, diameter. 



Prime power-diesel engines. Water depth-'300 feet 



Freqi 



jency 



Hz 

 Hz 

 Hz 

 Hz 



Source 



1 Level (1/3 Octave Band at ; 



1 Yard) 







12 



72 



180 



250 



129 dB 

 138 

 132 

 125 



; re 1 micropascal 







Case 



I: 



Optimal Propaqat 



:ion (Cylindrical Spreading) 



ng Assumption 







snt 



Noise 



Condition 



Animal Listeni 







A. Good Detection 

 (1/3 octave crit. band) 



Frequency Detection Range 



B. Conservat 

 (100 Hz crit. 



ivs Detection 

 band) 



Ambi( 



Frequency Detection 



Range 



1. High Ambient 72 Hz 30 Kyd 13 nm 180 Hz 66.5 Kyd 3.2 nm 



2. Medium Ambient 72 Hz 200 Kyd 99 nm 180 Hz 80 Kyd 39 nm 



3. Low Ambient 180 Hz 2500 Kyd 1230 nm 180 Hz 800 Kyd 395 nm 



Case II: Conservative Propagation (Spherica l Spreading) 



Animal Listening Assumption 



A. Good Detection B. Conservative Detection 

 (1/3 octave crit. band) (100 Hz crit. band) 



Ambient Noise Condition Frequency Detection Range Frequency Detection Range 



1. High Ambient 72 Hz 190 yds 0.09 nm 180 Hz 80 yds 0.04 nm 



2. Medium Ambient 72 Hz 450 yds 0.22 nm 180 Hz 290 yds 0.14 nm 



3. Low Ambient 180 Hz 2400 yds 1.20 nm 180 Hz 1500 yds 0.40 nm 



G-41 



