RODERICK: FORWARD SCATTERED LOW-FREQUENCY SOUND FROM THE SEA SURFACE 

 0- 



-10 



-30 



-40 



ACOUSTIC SPECTRUM 



100 Hz 



1917-1927 



SURFACE WAVE 



SPECTRUM 



1918 02-1926 28 



-20 



-50 



— ACOUSTIC SPECTRUM 



100 Hz 



2II0-2I2I 

 --SURFACE WAVE 

 SPECTRUM 



2110 00-2116 15 



10 -08 -06 -04 -02 00 02 04 06 08 10 -10 -08 -06 -04 -0 2 2 04 06 0.8 10 



CD 



-ACOUSTIC SPECTRUM 



250 Hz 



I93I-I94I 

 - SURFACE WAVE 

 SPECTRUM 



1931 00-1933 30 



1937 24-1939 



3 



o 



C/5 



-50 



-20- 



-30- 



-10 -08 -06 -04 -Q2 02 04 06 08 10 



-10 -08 -06 -04 -0 2 00 2 04 06 08 10 



ACOUSTIC SPECTRUM 



500 Hz 



!944-l954 

 — SURFACE WAVE 

 SPECTRUM 



1944 24-1946 54 



1951 30-1954 00 



— ACOUSTIC SPECTRUM 



500 Hz 



2147-2157 



SURFACE WAVE 



SPECTRUM 



2147 00-2152 58 



-40- 



-10 -08 -06 -04 -02 00 02 04 06 08 I -| -08 -06 -04 -02 00 02 04 06 08 10 



I FREQUENCY (Hz) D 



Figure 10. DOPPLER SPECTRUM FiEASUREIIENTS 

 AT 100, 250, AND 500 Hz 

 (from Brown and Frisk, 1974) 



344 



