ACOUSTIC INSTRUMENTS
Two SIMRAD scientific echo sounders. 38 and 120 kHz, were used during the survey for estimation of fish density. In addition an ES 400 split beam sounder was used.
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INSTRUMENT SETTINGS |
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EK 400/38 |
EK 400/120 |
ES 400 |
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Range |
0-100 or 0-250 |
0-100 |
0-25 to 0-250 |
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Transm. |
High (5000 W NOM) |
High (1250 W NOM) |
EK/ES adapter |
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Bandwidth |
3.3 kHz |
3.3 kHz |
3.5 kHz |
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Pulselength |
1 ms |
1 ms |
1 ms |
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TVG |
20 log R |
20 log R |
40 log R |
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Attenuator |
20 dB |
0 |
Fixed |
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Rec. gain |
7 |
5 |
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Transducer |
8°x8° ceramic or split beam |
Ceramic 10 cm circular |
Split beam 10° |
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Presentation mode: Compensated |
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EK 400/120 was coupled to the other QM integrator. Cain 10 dB x 10. Threshold 0.
ES 400 was connected to an Epson printer for hardcopy of the size distribution diagram (histogram).
Calibration on standard copper sphere.
EK 400/38: SL + VR = 140.8 dB (Transd. 8° x
8°)
EK 400/38-ES: SL + VR = 137.3 dB (Split beam
transm.)
Sonar
An ST sonar was used to detect fish schools close to the surface. Recorder range 0-250 m.
Calibration of instruments “Dr. Fridtjof Nansen” 1905-86
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Locality |
Transducer |
SL + VR |
Instr. constant |
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3/2/85. |
B.d. |
Tigres |
30 x 30 |
140,7 |
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28/4/85 |
“ |
“ |
30 x 30 |
140,8 |
0,94 |
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29/4/85 |
“ |
“ |
ES |
137,3 |
2,02 |
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10/8/85 |
P. Alex. |
ES |
137,3 |
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8/11/85 |
B.d. |
Tigres |
ES |
137. 1 |
2,28 |
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“ |
“ |
30 x 30 |
140,8 |
0,94 |
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Survey assignment DR. FRIDTJOF NANSEN |
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Period |
Assignment |
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FEB 1975-NOV 1976 |
NW ARABIAN SEA |
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JAN-JUN 1977 |
PAKISTAN |
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AUG 1977-JUN 1978 |
MOZAMBIQUE |
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JUL 1978 |
SEYCHELLES |
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AUG-SEP 1978 |
SRI LANKA |
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APR-JUN 1979 |
SRI LANKA |
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JUL-AUG 1979 |
OMAN AND ADEN GULFS |
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SEP-NOV 1979 |
BURMA |
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NOV-DEC 1979 |
BANGLADESH |
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JAN-FEB 1980 |
SRI LANKA |
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MAR-APR 1980 |
BURMA |
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MAY 1980 |
BANGLADESH |
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JUN-AUG 1980 |
MALAYSIA/THAILAND/INDONESIA |
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SEP-NOV 1980 |
MOZAMBIQUE |
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DEC 1980 |
KENYA |
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JAN-FEB 1981 |
OMAN AND ADEN GULFS |
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MAR 1981 |
EGYPT |
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MAR 1981 |
TUNIS |
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APR 1981 |
ALGIER |
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APR-DEC 1981 |
WEST-AFRICA |
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DEC 1981-APR 1982 |
WEST-AFRICA |
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JUN 1982 |
TANZANIA |
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AUG 1982 |
KENYA |
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SEP-OCT 1982 |
MOCAMBIQUE |
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NOV-DEC 1982 |
TANZANIA |
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FEB-MAR 1983 |
GULF OF OMAN/PAKISTAN |
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MAY-JUN 1983 |
KENYA/TANZANIA/MOCAMBIQUE/MADAGASCAR |
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AUG-SEP 1983 |
MALDIVES/PAKISTAN/IRAN |
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NOV-DEC 1983 |
GULF OF OMAN/OMAN EEZ |
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JAN-MAR 1984 |
PAKISTAN/S. YEMEN/SOMALIA/ETHIOPIA |
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APR-JUN 1984 |
OMAN/IRAN/PAKISTAN |
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AUG-SEP 1984 |
S. YEMEN/SOMALIA/OMAN |
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MAR-DEC 1985 |
CONGO/GABON |
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JAN 1985-JUN 1986 |
ANGOLA |
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AUG-DEC 1986 |
WEST-AFRICA |
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FEB-DEC 1987 |
CENTRAL-AMERICA |
