ME70 - Marine Radar SIMRAD - Free user manual and instructions

Type	Scientific multibeam echo sounder system
Brand	Simrad
Model	ME70
Frequency range	70 kHz to 120 kHz
Number of beams	Up to 45 beams in fan plus 2 reference beams (all configurable as split beams)
Beam opening angles	Alongship and athwartship: selectable 2° to 20° (depending on frequency and steering)
Operating sector athwartship	Maximum 140° with reduced sidelobe suppression; centre angle ±45°
Motion compensation	Roll ±10°, Pitch ±5°, Heave
Sidelobe level	Less than -35 dB (configurable down to -70 dB)
Transducer elements	800 individual elements
Transducer technology	Ceramic polymer composite
Transducer housing	Circular, outer diameter 677 mm, housing diameter 700 mm
Transceiver channels	800 Tx and 800 Rx channels
Beamforming	Cluster of six computers, 1 Gb Ethernet
Transceiver unit dimensions	Height 1921 mm, Depth 900 mm, Width 600 mm
Power cabinets	3 units, each 812 x 418 x 600 mm (HxDxW)
Operator station	Commercial workstation with Windows XP
Calibration	Included, with tungsten sphere
Minimum acquisition depth	Less than 1 m below transducer (depending on beam mode)
Data output	Continuous output of beam data for echo integration and 3D visualization

Frequently Asked Questions - ME70 SIMRAD

What is the Simrad ME70?

The Simrad ME70 is a scientific multibeam echo sounder system designed for fishery research, offering quantitative data and high operational flexibility for biomass estimation, fish school characterization, and behavior studies.

How many beams does the ME70 support?

The ME70 supports up to 45 beams in a configurable fan plus two additional reference beams. All beams can be configured as split beams for single target analysis.

What is the frequency range of the ME70?

The ME70 operates in the 70 kHz to 120 kHz frequency range, allowing flexible beam steering and frequency selection.

How is the ME70 calibrated?

Calibration is performed using a built-in utility with a tungsten sphere as a reference target. Individual gain parameters for each beam are adjusted to provide calibrated target strength and volume backscattering measurements.

What is a split beam configuration in the ME70?

In split beam configuration, each beam is divided into quadrants to determine the angular position of targets. This allows precise target strength measurements and tracking. The ME70 can have all beams as split beams plus two adjustable reference split beams.

What data output options does the ME70 provide?

The ME70 provides continuous output of beam data including non-TVG compensated power, sample Sv, sample TS, single target detections, and detected depth. It also outputs element data for post-processing.

Can the ME70 be operated remotely?

Yes, remote systems such as data loggers can subscribe to data and parameters from the ME70 via two-way communication, allowing efficient integration with external post-processing systems.

What motion compensation does the ME70 have?

The ME70 compensates for roll (±10°), pitch (±5°), and heave, ensuring stable beam pointing and accurate data collection even in rough seas.

What is the minimum depth the ME70 can measure?

The minimum acquisition depth is less than 1 meter below the transducer, depending on the beam mode configuration.

How does the ME70 achieve low sidelobe levels?

The ME70 uses two-way sidelobe suppression and Frequency Rotated Directional Transmission (FRDT) to achieve very low sidelobe levels (down to -70 dB) and minimal beam interleakage.

USER MANUAL ME70 SIMRAD

We are proud to introduce the world's first quantitative multibeam echo sounder for fishery research applications

System overview

The Simrad ME70 offers quantitative data and high operational flexibility. It provides a configurable wide fan of stabilized and calibrated beams for biomass estimation, fish school characterization. and behaviour studies.

All beams can be configured as split beams providing data for single target analysis, such as target strength measurements and target tracking.

The sector of calibrated narrow split beams with low sidelobe levels and short pulse lengths allow for accurate biomass estimation very close to the bottom. The ability to adjust the athwartship centre angle of the fan enables you to use the system for studying fish close to ridges and slopes. The design also permits you to use all the beams over the full frequency range pointing in one direction for frequency comparison.

Not just an ordinary multibeam sounder

Within the bandwidth of the transducer, the limits for beam steering, and the minimum achievable beam opening, you can select the directions, frequencies, and opening angles for the beams in the Simrad ME70.

You will be able to configure the system to fit your requirements, and the system will provide you with a real-time display for quality control of the current data acquisition.

The system configuration can be tailored to any user requirements, allowing for choice of beamwidths as well as transmission modes.

Low sidelobe levels and beam interleakage

Low sidelobes are important for two reasons. The obvious one is to avoid that strong targets in side lobes are mistaken for weak targets in the main lobe. Secondly, you do not wish to see strong bottom echoes from the sidelobes. Even the vertical receiver beam may benefit from low sidelobes

Key points

• The Simrad ME70 operates in the 70 to 120 kHz frequency range.
• The Simrad ME70 provides a configurable acoustic fan containing 3 to 45 stabilized beams.
• All beams can be configured as split beams.
• Calibration software included.
• Minimum beam opening is 2^ depending on operational frequency and steering.
• 140^ maximum total swath width.
• The athwartship centre angle of the fan can be adjusted from +45^ to -45^ .
• Minimum acquisition depth is less than 1 m below the transducer depending on beam mode configuration.
• Sidelobe levels and beam interleakage are adjustable from -35 to -70 dB depending on beamwidth and frequency configuration.

3D rendering of a red cylindrical mechanical component with bolt holes (no text or symbols)

in case of a sloping bottom.

Very low two-way sidelobe levels are obtained by using two-way side lobe suppression. Very low beam interleakage is obtained by using Frequency Rotated Directional Transmission (FRDT) where the frequency band is distributed over all the beams.

Since each beam has its own frequency and the fan width is configurable, the design also allows you to use all the beams over the full frequency range pointing in one direction for frequency analysis of targets.

Calibration

A calibration utility is implemented as a special built-in function in the Simrad ME70 system. Each beam configuration of interest can be calibrated using a reference target located under the ship.

Individual gain parameters for each beam are adjusted to provide calibrated target strength and volume backscattering strength measurements.

Splitbeam configuration

All beams can be configured as split beams. In addition, two adjustable reference split beams are available. These allow you to compare ME70 data with data from other split beam systems, for example the EK60. The reference beams can for example have 7x7 degrees opening angles, and operate on 70 and 120 kHz.

The data from the individual split beams are presented in the same way as on other Simrad scientific sounders.

Data output

It is possible to set up continuous output of all beam data. This can be used for echo integration and 3D visualisation. The output data for each beam include for example:

• non-TVG compensated sample power and sample angle
• 20 log R compensated sample Sv
• 40 log R compensated sample TS
• 40 log R compensated single target detections
- Detected depth

It is also possible to output the element data for post processing and analysis purposes.

Remote operation

Remote systems, such as data loggers and external post-processing systems, can subscribe to data and parameters from the Simrad ME70. The parameters can also be queried and defined by the remote system. In this way the communication between the ME70 and the remote system can become an efficient, configurable, two-way communication.

This capture provides a typical presentation of fish schools. You can see five of the 31 beams, as well as the fan presentation. The menu is hidden from view. (Data kindly provided by Ifremer, France.)

graph TD
    A["Beamforming computers"] <--> B["Network controller"]
    B <--> C["TRXU Transceivers"]
    D["Operator station"] --> B
    E["Power cabinets"] --> C
    F["CD10102C"] --> G["Red cylindrical device"]

System diagram

Operator station

The operator station comprises a computer running Windows XP® operating system. It is connected to the ship's network, and can communicate with external post-processing applications.

Transceiver

The transceiver circuitry comprises three transceiver shelves, a network controller, and six beamforming computers.

Power Cabinets

Three separate power cabinets provide the operation power to the TRXU Transceivers.

Transducer

The transducer array is mounted in a circular housing. Its outer diameter is 677 mm. The array contains 800 individual elements.

System

• Scientific multibeam echo sounder

Acoustics

Frequency range

- 70 kHz to 120 kHz

Beams

- Organisation: Fan

• Total number of beams: Maximum 45 beams in fan plus two reference beams

• Number of split beams: Maximum 45 split beams in fan plus two reference beams

Beam opening angles

- Alongship: Selectable 2^ to 20^

- Athwartship: Selectable 2^ to 20^

- Opening angles depend on beam steering and frequency.

Operating sectors

- Athwartship: 60^ Maximum 140^ with reduced sidelobe suppression

- Athwartship sector centre angle: ± 45^

- Alongship sector centre angle: ± 5^

Motion compensation

- Roll: ± 10^

- Pitch: ± 5^

- Heave

Sidelobe and beam

interleakage

- Alongship: Less than -35 dB

- Athwartship: Less than -35 dB

- Configurable depending on beamwidth and frequency configuration.

Transmission

• FM with pulse duration 128 to 5120 μs

• CW with pulse duration 64 to 5120 μs

- Source level: > 225 dB (depending on beam opening and frequency)

Receiving

- Receiver dynamic range: 150 dB (instantaneous)

Calibration

• Calibration software included
• Target: Tungsten sphere

Hardware

Transducer

• Number of elements: 800
• Technology: Ceramic polymer composite
- Housing: Circular
• Housing diameter: 700 mm

Transceiver Unit

• Individual Tx channels: 800
• Individual Rx channels: 800
- Beamforming: Cluster of six computers

- Communication: 1 Gb Ethernet

• Physical dimensions:

Height: 1921 mm

Depth: 900 mm

Width: 600 mm

Power cabinets

• Quantity: Three cabinets
• Physical dimensions:
Height: 812 mm
Depth: 418 mm
Width: 600 mm

Operator Station

• Type: Commercial workstation
- Operating system: Microsoft® Windows XP®

Optional systems

• Element data logger
• Bathymetric processing system

Yellow industrial robotic arm with red base, partially submerged in water (no visible text or symbols)

The transducer array set up for test and calibration at Simrad's laboratory

Note that technical specifications can be altered without prior notification!

(855-165184 / Rev.C / November 2006)