Instrumentation

All vessels collect 38 kHz acoustic data from either Simrad EK60, ES60 or ES70 echo sounders. In all cases the 38 kHz echo sounders are connected to Simrad ES38B transducers. This is a narrow-beam (7°) ceramic transducer with good long term stability and manufacturer supplied calibration parameters.

The Simrad EK60 is a split-beam Windows(TM) operated echo sounder with built-in calibration. It can operate seven echo sounder frequencies simultaneously ranging from 18 to 710 kHz. The EK60 is specifically suited for permanent installation onboard a research vessel. It is still compact and a natural choice for portable use. The Simrad ES60 is a single beam echo sounder that can use up to four frequencies simultaneously.

The basic Simrad EK60 scientific echo sounder system consists of one transducer, one transceiver unit and one processor unit (computer). 

Schematic showing the basic components of an EK60 echosounder: A) Display, B) Personal Computer processor, C) Commercial Ethernet switch, D) One or more General Purpose Transceivers (GPT), E) Transducers. Image source: http://www.simrad.com/ek60#system_description
Schematic showing the basic components of an EK60 echosounder: A) Display, B) Personal Computer processor, C) Commercial Ethernet switch, D) One or more General Purpose Transceivers (GPT), E) Transducers. Image source: http://www.simrad.com/ek60#system_description

Table: Basic data collection settings

 

Parameters  38 kHz  120 kHz  200 kHz
Power (W)2,000500120
Pulse length (ms)2.0481.0241.024
Logging range (m)0–2,0000–5000–500
Absorption (dB/m)0.0098
Sound speed (m/s)1,493.89