Nortek Signature VM Ocean 55k Hz frontview

Vessel-Mounted

VM Ocean

100|75|55 kHz

Delivers vessel-mounted ADCP capabilities with either an optional scientific echosounder for biomass measurements (100 kHz) or very long-range measurements (55 kHz)

A comprehensive, easy-to-use system optimized for large ocean-going vessels
Enables both long-range (1000m) and high-resolution current profiles from a single vessel-mounted instrument (Signature55)
Optional scientific echosounder with multiple modes for biomass (Signature100)

Guide to Vessel-Mounted ADCPs Go to Technical Specifications

Overview

Until now, epipelagic and mesopelagic VM ADCP surveys could not deliver the resolution, precision or range to examine the ocean boundary layer in detail. The VM Ocean system with the Signature100 ADCP enables biomass studies in the upper-ocean boundary layer simultaneous to current measurements, with a combined ADCP and scientific echosounder. The innovative dual-frequency design of the Signature55 ADCP allows for both very long-range (up to 1000m) current profiles as well as higher-resolution measurements.

Download our guide to Vessel-Mounted ADCPs here.

Currents
Echosounder
Bottom track

Highlights

Comprehensive, easy-to-use system
Automated processing fir data viewing onboard
Instrument allows for flexible deployments, either vessel-mounted or standalone
Take both long-range and high-resolution measurements from one instrument with innovative dual-frequency transducers (Signature55)
Current profiling range up to 300-400m and gather biomass information with scientific echosounder (Signature100)

Usage

Internal wave detection using echosounder (100 kHz)
Upper-ocean boundary-layer studies, current profiling range up to 300-400m (100 kHz)
Detection of krill or plankton in the water column (100 kHz)
Deep-water current profiles (up to 1000m), ocean discharge (55 kHz)

Setup

The 100 and 55 kHz units are typically mounted inside the hull or in a lowered structure attached to the hull, such as an instrument gondola. Nortek has a mounting guide available.

Deployment

View current velocity data in real time from the VM acquisition software while onboard the vessel. Gather long range current speed and direction information with the 55 kHz unit or use the 100 kHz unit for intermediate profiles and biomass estimates.

Data

Biomass estimates of fish and krill and detections of internal waves with the optional 100 kHz scientific echosounder can be further processed using Echoview software. Process and export current data subsets of interest using the VM review software once your survey has ended.

Water Velocity Measurements - Signature VM 100 kHz

Profiling range**	300-400 m
Doppler processing	Broadband & Narrowband
Cell size	3-16 m
Max no. cells	200
Min. blanking	2
Minimum accuracy	1% of the measured value ± 0.5 cm/s
Velocity resolution	0.1 cm/s
Maximum sampling rate	1 Hz (1/3 Hz with BT and echosounder)
Velocity range (along beam)	5 m/s
No. of beams	4 slanted at 20°
	** Maximum range depends on acoustic scattering conditions and cell size.

Water Velocity Measurements - Signature VM 75/55 kHz

Profiling range**	685/900-1000 m
Doppler processing	Broadband/Broadband & Narrowband
Cell size	5-20 m
Max no. cells	200
Min. blanking	2
Minimum accuracy	1% of the measured value ± 0.5 cm/s
Velocity resolution	0.1 cm/s
Maximum sampling rate	1 Hz
Velocity range (along beam)	5 m/s
No. of beams	3 slanted at 20°
	** Depending on acoustic scattering condition.

Bottom velocity measurements - Signature VM 100 kHz

Single ping std @ 3 m/s	TBA
Long-term accuracy	TBA
Minimum altitude	5 m
Maximum altitude	540 m
Velocity resolution	0.01 mm/s
Maximum sampling rate	1/2 Hz (1/3 Hz with VP and echosounder)

Bottom velocity measurements - Signature VM 75/55 kHz

Single ping std @ 3 m/s	TBA
Long-term accuracy	TBA
Minimum altitude	50 m
Maximum altitude	1000 m
Velocity resolution	0.01 mm/s
Maximum sampling rate	1/2 Hz

Echo intensity (slanted beams) - Signature VM 100 kHz

Sampling	Same as velocity for slanted beams
Resolution/dynamic range	0.5 dB/70 dB
Transducer acoustic frequency	100 kHz
No. of beams	4 slanted at 20°, optional vertical beam for echosounder
Beam width	6.1° (slanted)

Echo intensity (slanted beams) - Signature VM 75/55 kHz

Sampling	Same as velocity
Resolution/dynamic range	0.5 dB/70 dB
Dynamic range	70 dB slanted beams
Transducer acoustic frequency	75 and 55 kHz
No. of beams	3 slanted at 20°
Beam width	4.5°-5.5°

Echosounder option - Signature VM 100 kHz

No. of beams	1 vertical
Transducer acoustic frequency	70-120 kHz
Sampling	1 Hz (1/3 Hz with VP and BT)
Transducer beam width	15° @ 70 kHz, 8.7° @ 120 kHz
Resolution	0.375 –4 m
Resolution/ dynamic range	0.01 dB/130 dB
Transmit pulse	Monochromatic 70 kHz, 90 kHz and 120 kHz or frequency chirp (90 kHz, 50% BW)
Transmit power	7.5-120 W adjustable
Chirp signal processing	Pulse compression or binned frequency response

Echosounder option - Signature VM 75/55 kHz

No. of beams	N/A
Transducer acoustic frequency	N/A
Sampling	N/A
Transducer beam width	N/A
Resolution	N/A
Resolution/ dynamic range	N/A
Transmit pulse	N/A
Transmit power	N/A
Chirp signal processing	N/A

Other - Signature VM 100 kHz

Temperature sensor range / accuracy	-4 °C to 40 °C / 0.1 °C
Pressure	Piezoresistive (sampled at meas. rate)
Standard range	0-1500 m (inquire for options)
Accuracy/precision	0.1% FS / Better than 0.002% of full scale
Compass and tilt	Solid-state magnetometer and accelerometer (Max 1 Hz sample rate)
Data recording	16 GB (inquire for options)
Data cable	10 m Ethernet cable. Other lenghts available
IO	Ethernet
DC input	24-48 V DC

Other - Signature VM 75/55 kHz

Temperature sensor range / accuracy	-4 °C to 40 °C / 0.1 °C
Pressure	Piezo resistive
Standard range	0-1500 m (inquire for options)
Accuracy/precision	0.1% FS / Better than 0.002% of full scale
Compass and tilt	Solid-state magnetometer and accelerometer
Data recording	16 GB (inquire for options)
Data cable	30 m Ethernet cable (inquire for options)
IO	Ethernet
DC input	48 V DC

Dimensions - Signature VM 100 kHz

Maximum diameter	455 mm
Maximum length without room for internal batteries	392 mm
Weight in air	29 Kg (5 beams)

Dimensions - Signature VM 75/55 kHz

Maximum diameter	650 mm
Maximum length without room for internal batteries	314 mm
Weight in air	57 Kg

Environmental, Signature VM ADCP

Operating temperature	-4 °C to 40 °C
Storage temperature	-20 °C to 60 °C
Vibration	IEC 60068-1/IEC60068-2-64
EMC approval	IEC 61000
Depth rating	1500 m – Bottom track is limited to surface vessels
Connectors	Straight fitted MCBH6F (Ethernet)
Housing	Small instrument housing
Material	POM with titanium fasteners

Processing unit

Processor/memory	Intel i5/8 GB
Hard disk	SSD, 256 GB
Operating system	Windows® 11 IoT Ent LTSC
Housing	19" rack-mountable 2 HE
Dimensions	482x87x400 mm
Input	110-240 V AC, 100 W Max
Total weight	7 kg
Connections*	Power, Signature ADCP, 2x DisplayPort, 1x LAN, 2x USB, 4x RS232\|RS422\|RS485 configurable port*
	* Processing unit requires heading and GNSS input over Serial or Ethernet

Nortek VM acquisition software

Acquisition input	Signature VM - binary, Advanced Navigation GNSS - binary, KM - binary, common NMEA
Timing	IEEE1588/PTP or NTP for absolute time stamping of Gyro/GNSS/Signature ADCP data or < 0.6 s under $ZDA NMEA
Configuration	Signature VM ADCP, Alignment offsets, Outputs
Display	Vessel track in map, Bottom-track velocity, Bottom-track depth, Velocity magnitude and direction, Echo amplitude (slanted beams), Echo correlation (slanted beams), corrected relative volume backscatter (100), Signature VM BT and VB + NMEA GGA, HDT, VTG
Status	Signature VM BT and VB + NMEA GGA, HDT, VTG
Output	Online: NMEA data formats. Offline: CSV, ASCII VMT, MATLAB, MATLAB VMT, MATLAB QRev, KML

AHRS option

Accelerometer dynamic	± 2 g
Gyro dynamic range	± 250°/sec
Magnetometer dynamic range	± 1.3 Gauss
Pitch and roll range/resolution	± 90° (pitch), ± 180° (roll)/0.01°
Pitch and roll accuracy	± 2° (dynamic)3), ± 0.5° (static, ± 30°)
Heading range / resolution	360°, all axes/0.01°
Heading accuracy	± 3° (dynamic)3), ± 2° (static, tilt < 20°)
Sampling rate	Same as measurement rate

Technical drawings

Signature 100 VM General Arrangement Download

Signature 55 VM General Arrangement Download

Approvals

Declaration of conformity Download

Declaration of conformity - Signature VM Download

Declaration of conformity - Signature 55 Download

Environmental test report, Vibration test - Signature 55 Download

Statement of Compliance - Signature 55 Download

Recycling & Disposal Guidelines

Recycling & Disposal Guidelines Download

Main product

Signature100 VM Ocean

Signature55 VM Ocean

Probe type /head

4-beam head (100)

5-beam head (adds 95 kHz center transducer for echo sounder)(100)

3 beam head (55)

Housing

Short, no room for battery (requires external battery canister for bottom-mount use)

Memory

16 GB SD card data logger

64 GB SD card data logger

128 GB SD card data logger

256 GB SD card data logger

Pressure sensor

Pressure sensor, 0-1500 m, accuracy 0,1% of FS (standard)

Pressure sensor, 0-100 m, accuracy 0,1% of FS (option)

Cables

AD2CP: 20 m Ethernet cable towards the junction box with MCIL6MP on both ends

Mounting

Vessel-mounted over the side

Vessel hull-mounted

Unmanned Surface Vehicle (USV) mounted (please inquire)

Other

Compass and tilt sensor

AHRS (option)

Support resources

FAQs

Manuals

Nortek VM Coastal and VM Ocean Manual

Understanding vessel-mounted current measurement

User stories Oceanography Vessel-mounted

Exploring Mediterranean Sea waters with a state-of-the-art combined current profiler and echosounder

Educational videos Oceanography Vessel-mounted

Simplifying vessel-mounted current measurement

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