With the Simrad FS70 the rugged FS70 Trawl Unit is placed behind the headrope. The Trawl Unit contains the Sonar Head, a 200 kHz echo sounder, and the communication circuitry required to receive data from the wireless sensors.
Other wireless sensors are then placed on the trawl to suit your requirements. These report their data to the Trawl Unit, or to a PI system on the bridge.
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