Because of eSonar’s full suite of trawl management technology, fishing companies and scientists across the globe rely on us for trawl management solutions. For every trawling activity we can provide you with the system you need.
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All eSonar sensors are powered by a rechargeable Lithium Ion battery. And with innovations by our power management and microprocessor experts, these sensors have an extended operating life of 400+ hours between charges.
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Our marine grade, certified Products include the following:
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Digital Receiver — Communications interface between the hydrophone and vessel display(s)
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Hydrophone — Receives acoustic signals from sensors and relays the data to the Digital Receiver. May be one of two types:
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Linear Catch Sensor — Monitors and displays trawl catch-rate
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Door Spread Sensors — Monitors trawl door geometry and net configuration
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Wing Spread Sensors — Monitors trawl wing geometry and net configuration
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Headline Height Sensor — Monitors depth, trawl opening, and trawl shape
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Multi-function Sensor — Monitors trawl position for target species (depth, temperature, pitch and roll)
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Grid Sensor — Monitors the grid angle of the trawl
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Bottom Contact Sensor — Monitors trawl contact with the bottom
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Check out our Trawlvue Monitoring System brochure for more information:
DIGITAL RECEIVER
Installed on the bridge, engine room or any convenient location on the vessel, this marine grade technology receives data from the hydrophone and relays it to one or more displays via an Ethernet.
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SPECIFICATIONS:
Dimensions: 8.0" L x 5.5" W x 1.5" H
Power: 9-36 VDC 0.5A max
Connection: Serial Port (Ethernet available upon request).
2 Hydrophone Channels Port and Starboard
96kHz sampling rate
+12 VDC phantom power to hydrophone preamps
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HULL MOUNTED HYDROPHONE
Receives acoustic signals from the eSonar sensors and relays data to the Digital Receiver. The preamp is built into the hull-mounted receiver and is available in:
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One-piece, single transducer model, or
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Two-piece, two-transducer, full coverage system
The hull-mounted hydrophone is installed when the vessel is out of the water in dry dock.
SINGLE HYDROPHONE CONFIGURATION
Beam Width 50° horizontal, 50° vertical.
DOUBLE HYDROPHONE CONFIGURATION
Beam Width 50° - 80° horizontal, 50° vertical.
MATERIAL: Molded Epoxy and polycarbonate with
50 ft of shielded cable for attachment to the deck unit.
28 KHz receiver providing high sensitivity for reception over long distances.
ACCESSORIES
Housing
Thru-hull fitting
50 ft cable.
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TOWED HYDROPHONE
A versatile way to receive acoustic signals from the eSonar sensors. Normally deployed and towed from the side of the vessel in ice-free conditions. This unit is popular on vessels that are not scheduled for dry dock. It is also ideal for operations where the eSonar system will be deployed on more than one vessel.
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SPECIFICATIONS
Material: Polycarbonate housing and Molded Epoxy, 150 feet of Kevlar reinforced cable
Beam Pattern: 50° Conical
Accessories: 150 ft cable.
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LINEAR CATCH SENSOR
Monitors trawl catch-rate. As the cod-end of the net expands with fish, the catch sensor-cord detects and signals the increasing volume of the catch. This data is relayed to the vessel display.
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eSonar can help to calculate the correct number of catch sensors required to effectively monitor the catch.
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With real-time display of the amount of fish in your trawl, you can haul the net as soon as it is full or as soon as it has passed through the main school of fish. Saving you time and fuel.
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As an added benefit, with pitch and roll also available on the catch sensor, you can reduce net damage caused by the rolling of the cod-end as the net fills.
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SPECIFICATIONS
Measurement: Net expansion/catch monitoring
Telemetry Frequency: nominal 28 kHz; programmable
Weight in air: 6 kg
Battery life: Up to 3 weeks for the basic sensor
Frequency: Programmable
Additional measurements (Optional): Depth, Temp, Pitch and Roll
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DOOR SPREAD SENSOR
Monitors trawl door geometry and provides real-time feedback on trawl performance. This sensor also provides data on net configuration—helps ensure the net is not skewed or collapsed on the bottom. By adding depth, pitch and roll to the door spread sensor’s capabilities, you can ensure that trawl doors are working. With control over these parameters you can reduce both fuel consumption and the amount of time you spend on each haul.
SPECIFICATIONS
Measurement: Distance between master and slave sensor, door depth and door pitch/roll.
Measurement range: 300m
Accuracy: +/- 1% of full scale.
Measurement Frequency: nominal 90 kHz, programmable
Telemetry Frequency: nominal 28 kHz, programmable
Battery life: Up to 3 weeks for the basic sensor
Depth: 200 Bar
Pitch: +/- 180°
Roll: +/- 180°
Weight in air: Master, 6 kg; Slave, 6 kg
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WING SPREAD SENSOR
Monitors trawl wing geometry and provides real-time feed back to the vessel display on trawl performance. By adding depth, pitch and roll to the wing spread sensor’s capabilities, you can ensure that the wings are working properly. With control over these parameters you can decrease the time spent on each haul and reduce fuel consumption.
SPECIFICATIONS
Measurement: Distance between master and slave sensor.
Measurement range: 200m
Accuracy: +/- 1% of full scale
Measurement Frequency: nominal 150 kHz; programmable
Telemetry Frequency; nominal 28 kHz; programmable
Battery life: up to 3 weeks for the basic sensor.
Depth: 200 Bar
Pitch: +/- 180°
Roll: +/- 180°
Weight in air: 6 kg; Slave: 6 kg
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HEADLINE HEIGHT SENSOR
Measures the distance from the headline to the footrope, and from the headline to the bottom. It can also measure depth, pitch, roll and temperature.
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The Headline Sensor helps maintain the proper trawl opening so the net is fishing at its optimal shape, to maximize the catch rate and minimize time and fuel consumption.
SPECIFICATIONS
Measurement: Distance from headline to bottom, Distance from headline to footrope
Depth: 200 Bar
Temperature: -2 to + 30° Celcius
Pitch: +/- 180°
Roll: +/- 180°
Height Measurement range: Up to 60m
Accuracy: +/- 1% of full scale.
Battery life: Up to 3 weeks for a basic sensor
Measurement Frequency: nominal 200 kHz; programmable
Telemetry Frequency: nominal 28 kHz; programmable
Weight in air: 6 kg
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MULTI-FUNCTION SENSOR
Provides real-time feedback on trawl position for up to four selected parameters to maintain the trawl position for more effective harvesting of target species.
SPECIFICATIONS
Measurement: Water Temperature
Measurement Range: -2°C to +30°C
Battery life: Up to 3 weeks for a basic sensor
Depth: 200 Bar
Pitch: +/- 180°
Roll: +/- 180°
Accuracy: +/- 0.1°C
Weight in air: 6 kg
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GRID SENSOR
Monitors the trawl grid angle in real time and provides data to the display so any change in the angle can be corrected to maintain the optimum fishing position. Performs angle measurements from 0° to 180° with an accuracy of ±1°. It also allows depth monitoring.
SPECIFICATIONS
Measurement: Tilt
Measurement Range: 0° to 180°
Battery life: Up to 3 weeks for a basic sensor
Depth: 200 Bar
Pitch: +/- 180°
Roll: +/- 180°
Accuracy: +/- 1°
Weight in Air: 6 kg
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BOTTOM CONTACT SENSOR
Monitors trawl contact with the bottom to help adjust the trawl depth in real time.
Suspended from the trawl footrope, this sensor hangs close to vertical when the trawl is off the bottom. The sensor data on the vessel display will show an angle of approximately 90°. When the trawl contacts the bottom, the sensor is in a horizontal position. Sensor data on the vessel display will show an angle of approximately 0°.
SPECIFICATIONS
Measurement: Tilt
Measurement Range: 0° to 180°
Battery life: Up to 21 days for a basic sensor
Depth: 200 Bar
Pitch: +/- 180°
Roll: +/- 180°
Accuracy: +/- 1% Full Scale
Weight in Air: 6 kg
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