Fishing Echo Sounder (Simrad EK 80 with ADCP)

Attention:

Please note that operations of the Fishing Echo Sounder Simrad EK 80 requires experienced scientific staff on board and can be only operated on request. The system is not operated by the ship's crew. Request operations with the Fishing Echo Sounder Simrad EK 80 to AWI-Logistics in sufficient time prior to the cruise and clarify the data transfer after the cruise.

Data quality of Fishing Echo Sounder Simrad EK 80 is decreased by operating other Echo Sounders. Repeatable disturbances were detected from simultaneously operating a) POSIDONIA, b) Sonar Doppler Speed Log DOLOG and c) Sediment Echo Sounder Parasound P70. Switch off these Echo Sounders for high data quality.

Summary

Transducer Frequency:

18, 38, 70, 120, 200 kHz

Contacts

Components

The system consits of five "split beam" transducers (ES-18, ES-38B, ES-70-7C, ES-120-7C, ES-200-7C) located in the box keel, five General Purpose Transceivers (GPTs), two EK80 WBTs (45-90 kHz, 90-160 kHz) and a computer with installed data acquisition and processing software ER60 and EK80 in room A113.

Subdevices

Position

Data logging, storage and archiving

Logged parameters

Central geographical ship's position and time standard

Time synchronising of the computers is regulated via the affiliation to the Windows domain. Additionally, the NMEA-String ZDA is stored in the data files.
The geographical ship's position is transferred to the Master PC together with the NMEA-String and to the data files. There is no centering of the GPS Position to the transducers.

Rawdata storage on board

Mass data: The data acquisition and processing software ER60 creates rawdata in the mass storage. Please note that there will be a transit from Simrad EK60 to EK80 in 2018 changing data structure and volume.

root directory	\\polsrv1\data01\fishsounder\|
directory name	CruiseNo e.g. ANT25_3
file name	CruiseNo-Dyyyymmdd-Thhmmss.raw with: yyyy = year mm = month dd = day hh = hour mm = minute ss = second e.g. ANT25_3-D20090113-T144735.raw
Data volume (MB per day) ca	3500
Number of files per day ca	100

Dship

Reduced set of measurement data.

Device name	fishing echo sounder
Parameters	depth (18 kHz) [m]; depth (38 kHz) [m]; depth (70 kHz) [m]; depth (120 kHz) [m]; depth (200 kHz) [m]

Data archiving on land

After the cruise, the operator transfers the measurement data along with required meta data to AWI after consultation with the data scientist and AWI Logistics. Then, the data including meta data can be extracted from https://www.pangaea.de/ (for authorized users only). DShip data set can be extracted from https://dship.awi.de/.

File format(s)	*.txt
Calibration certificates	NO

Calibration

The EK80 system must be calibrated. Ideally, the calibration is executed before and after the measurement in the working area. So, the calibration parameters can be defined dependent the actual water conditions. For this reason a calibration on previous cruises will not lead to optimal results.

The calibration is performed using three winch systems positioning the calibration sphere below the transducers.
The winch system as well as their control must operated by the scientists. The laboratory electronic engineer may assist the setup of the system.

A calibration must be planned like all other scrientific work prior the cruise, because the calibration work needs time. Ideally half a day is requested, but will take longer (may be a whole day), if weather conditions decrease.
Ideally the calibration is performed in calm sea without wind. If wind forces the drift of the ship, the winches will not hang vertical anymore but will also drift. Under this conditions it is very difficult, to move the calibration sphere to the requested locations.

Furthermore, the calibration must be planned, because calibration equipment is not permanently on board. The winches etc. need storage capacities and are stored during harbour visit in Bremerhaven, only.

If you are planning to execute a calibration, please add the that work in formula "Einsatzplanung" and step in contact with schiffskoord@awi.de for further planning.

Page tree