NAVIKNOT

Multisensor Speed Log Series

The NAVIKNOT Multisensor Speed Log Series offers unlimited flexibility and has been designed with the most modern computer tools for application on all types of vessels. The Speed Logs of Northrop Grumman Sperry Marine measures Speed Over Ground (SOG) and Speed Through Water (STW) with a speed accuracy of +/-1% or 0.1kn whichever is greater.

The NAVIKNOT’s display provides ships water and ground speed information in an accessible way, for ease of use, quick interpretation and berthing and docking operations.

Benefits of the NAVIKNOT series:
 

•    Varied selection of speed and distance interfaces
•    Suitable for all types of vessels ranging from small pleasure craft to the largest crude carriers
•    Simple and low-cost installation
•    Type approved by Germanischer Lloyd to Marine Equipment Directive (MED) 96/98/EC
•    Support of docking manoeuvres by displaying the necessary information

Single and dual axis speed logs, 600 series with docking function, are available. The speed logs provide information about transversal and longitudinal ship’s speed. The systems can be interfaced with most modern peripheral equipment and speed output can be transmitted to ARPA radar, ECDIS, AIS, VDR,  etc.

Northrop Grumman Sperry Marine provides electromagnetic sensors, doppler transducers and satellite sensors as follows:

Electromagnetic Sensor (Single-Axis Water Speed)

The electromagnetic sensor houses a coil which, when energised with an AC current, produces a magnetic field around the sensor in the surrounding water. The ship’s motion through the water produces an electrical field  perpendicular to the magnetic field  and the ship’s motion. The resulting signal is picked up by the sensor electrodes and fed to the preamplifier, where it is converted into a digital format and transmitted to the NAVIKNOT electronics unit.

Doppler Transducer (Single-Axis Water Speed)

The Doppler transducer utilizes the Doppler frequency shift effect to determine the speed of a vessel through water. The transducer emits high-frequency sound pulses in the fore and aft directions through two transmitter windows. Two receiver windows in the transducer detect the return echo of the sound pulses. A time delay between pulse transmissions ensures that echoes are received from the undisturbed water outside the vessel’s boundary layer. The signals are processed to determine the ship’s fore/aft speed vector. The preamplifier transmits the speed information in a digital format to the NAVIKNOT electronics unit.

Satellite Sensor (Dual-Axis Ground Speed)

The satellite sensor makes use of GPS satellite signals to determine a ship’s longitudinal and transverse ground speeds. Two GPS receivers and three rate gyros integrated in an electronics unit, and a dual antenna unit, determine a vessel’s heading velocity, course and attitude. While the heading is referenced to the ship’s fore-and-aft line, the velocity and course represent the motion vector, i.e. the magnitude and direction of its motion over ground.

The information received from the satellites is processed in the electronics unit, which resolves the velocity data into the ship’s longitudinal and transverse ground speeds. The speed vectors combined with the rate-of-turn data are used to discern between translational and rotational movement of the vessel. These are used to determine the bow and stern transverse speeds shown in the docking display.

NAVIKNOT Features

NAVIKNOT Speed Velocity Log

The NAVIKNOT Multisensor Speed Log Series is a new generation in a long line of successful Northrop Grumman Sperry Marine speed logs. The 350, 450 and 600 series offer unlimited flexibility and have been designed with the most modern computer tools for application on all types and sizes of vessels including cruise ships, container ships, tankers, megayachts and a wide variety of other crafts, both new build and retrofit.

Flexible and Innovative

The speed log measurement capability at slow speed is vital for precise docking of tankers to oil loading and unloading facilities, as well as safe navigation in narrow channels or straits. Operation at high speed assists economical cruising in open seas. While retaining the measurement accuracy the time for installation and space required for installation will be reduced.

Control and Display Units

The innovative NAVIKNOT Multisensor Speed Log Series features two different-sized Control and Display Units (CDU) each with a large colour TFT display, and utilizes satellite-based technology (GPS) in addition to the traditional Doppler and Electromagnetic Sensors to provide the user with high-accuracy displays of dual-axis ground speed and/or single-axis water speed.

NAVIKNOT Control and Display Unit (CD) in a housing with bracket attachment

Full Features of the NAVIKNOT series:

• Speed accuracy ± 1% or 0.1 kn whichever is greater
• Large colour TFT display
• Display colours selectable by the operator
• Double-end ferry mode
• Miles counter (one total counter and one daily counter)
• Separate damping for speed display and outputs (0 – 99 sec.)
• Displays longitudinal and transverse speeds (transverse speed 600 S, 600 SE & 600 SD only)
• Remote control and display units are available in different sizes
• Integrated take-over function Remote-to-Master

Display Unit Specifications

NAVIKNOT Speed Velocity Log

VisionMaster SeaGuard operates over six frequencies on solid state technology to deliver the highest levels of resilience and situational awareness.

• Very high level of radar return – unique multi-beam operation ensures small targets are detected.
• Detection in heavy rain – system self-organises to automatically switch between the six frequencies, enabling small target detection even in the harshest weather conditions.
• Detection in all sea states – from calm to high seas, through advanced clutter reduction and multi-beam operation.
• Full 360-degree view of targets around the vessel – compared to just a front and side view with standard navigation radars.
• Exceeds all IMO requirements – for navigation radars to detect targets.

The NAVIKNOT multisensory speed log series houses a range of models that each perform differently, depending on whether they have an Electromagnetic Sensor, Doppler Transducer or Satellite Sensor.

See below for an overview of the NAVIKNOT series performances:

NAVIKNOT 350 E

Electromagnetic Speed Log System, Single-Axis Water Speed

• Master Control and display unit
• Digital and analogue speed repeaters
• Electronics Unit
• Preamplifier
• Compatible sensors: NF Type 2829, FNF III Type 4874, FNFII Type 4120, FN I Type 4040 or FNF I type 4726
• Optional Remote Control and Display Unit
• Optional Digital and analogue speed repeaters

NAVIKNOT 450 D

Doppler Speed Log System, Single-Axis Water Speed

• Master control and display unit
• Electronics Unit
• Preamplifier
• Compatible transducers: Doppler Transducer in gate Valve  
• Optional Remote Control and Display Unit
• Optional Digital and analogue speed repeaters

NAVIKNOT 600 S

Satellite Speed Log System, Dual-Axis Ground Speed, Docking Mode

• Master control and display unit
• Electronics unit
• Dual satellite antenna
• External Heading and Rate of Turn for enhanced docking accuracy
• Optional Remote Control and Display Unit
• Optional Digital and analogue speed repeaters

NAVIKNOT 600 SE

Satellite and Electromagnetic Speed Log System, Dual-Axis Ground, Speed and Single-Axis Water Speed, Docking Mode

• Master control and display unit
• Dual satellite antenna
• Electronics unit
• Preamplifier
• Compatible sensors: NF Type 2829, FNF III Type 4874, FNF II Type 4120, FNF I Type 4040 or FNF I Type 4826
• Optional Remote Control and Display Unit
• Optional Digital and analogue speed repeaters
• External Heading and Rate of Turn for enhanced docking accuracy

NAVIKNOT 600 SD

Satellite and Doppler Speed Log System, Dual-Axis Ground Speed and Single-Axis Water Speed, Docking Mode

• Master control and display unit
• Dual satellite antenna
• Electronics unit
• Preamplifier
• Compatible transducers: Doppler Transducer in Gate Valve
• Optional Remote Control and Display Unit  
• Optional Digital and analogue speed repeaters
• External Heading and Rate of Turn for enhanced docking accuracy

Speed Repeaters

NAVIKNOT Speed Velocity Log

Northrop Grumman Sperry Marine can provide additional Universal Digital and Analogue Speed Repeaters. For remote and easy installation, the consoles vary in size and can be installed in a watertight housing with a mounting bracket.

Universal Digital Speed Repeater

Analogue Speed Repeaters

Use Cases

Sea surveillance

• Search and rescue – increase your chances of detecting people in the water to significantly reduce delays and costs.
• Heavily trafficked seas – navigate more safely in waters with lots of small craft.
• Piracy detection – reduce the risk of potentially life-threatening situations with real-time automatic tracking of small, fast-moving craft to give more time to request assistance

Land surveillance

• Port surveillance – monitor smugglers and small craft exceeding speed limits or entering prohibited areas with real-time automatic tracking to improve efficiency.
• Critical infrastructure monitoring – safeguard against potential threats to power plants, wind farms, oil rigs, naval and ferry ports.

Aerial surveillance

• Helicopter detection – guide pilots to land on board in emergency medical situations or during bad weather.
• Drone detection – protect privacy against drones taking video footage.