Settings and performance of acoustic instruments
Echo sounders
|
Frequency |
38 kHz |
120 kHz |
|
|
|
Basic range |
0-100/0-250+250 |
0-100 |
|
* |
Bandwidth |
3.3 kHz |
3.3 kHz |
|
* |
Pulse length |
1.0 ms |
1.0 ms |
|
|
TVG and gain |
20 log R-20 dB |
20 log R-0 dB |
|
|
Recorder gain |
7 |
5/6 |
|
* |
Transmitter power |
4813 W |
233 W |
|
|
Transducer dimension |
8° × 8° |
10° |
|
|
(Ceramic) |
(30 x 30 cm) |
(Circular) |
|
|
Discriminator |
4-7 |
5-6 |
|
* |
Source level + voltage |
|
|
|
|
response |
140.7 dB |
114.9 dB |
|
|
Measured |
May 1984 |
August 1983 |
|
Integrators |
QD/38 kHz |
QM/120 kHz |
|
|
* |
Integrator threshold(All ch.) |
10 mV |
10 mV |
|
* |
Integrator gain |
30 dB |
10 dB × 10 |
|
* |
Depth intervals |
/4-25/25-50/50-75/ |
A: 4-50 |
|
|
Bottom channels |
/BI 6.0 m BII 0.1-0.4 m |
|
|
|
Bottom stop |
On |
On |
|
xx) |
Calculated instrumental constant (CI) |
0.082 |
|
* Parameters changed or new from previous cruises on R/V “Dr. Fridtjof Nansen” due to installation of Simrad EK-400 echo sounders and QD-integrator. Parallell integration on QD and QM (“old settings”) were made for reference purposes.Sonar ST (18 kHz) was operated in areas with schooling activity. Sonar S 109 was not used due to malfunctions.
xx) Scaling factor - 10.0 (Used for mapping purposes)
