Vigilant FAQs
FAQs
What is the sonar frequency and why?
The selected frequency of 70kHz provides an optimum design for power, size, range and background noise discrimination. Also, extensive analysis available in [ref] details how we are confident, based on the latest NOAA guidelines, that Vigilant will do no harm to marine fauna that may be listening in.
Ref: WFS/20/001: Assessment of Vigilant Environmental Impact
Why is the system designed in two parts?
The projector and receiver are both optimised for size while being necessarily dimensioned to achieve high performance in both range and elevation (depth). The physics of the underwater environment necessitates the dimensions – smaller will equal lower performance.
High resolution is an important feature of any sensor. For sonar the resolution is inversely proportional to the length of the transmitter and receiver arrays. To achieve high elevation resolution ‘taller is better’. Our system uses a separate vertical projector array to achieve elevation beamwidths of 2.5°, which are frequency encoded and steered over the entire 20° vertical field of view.
More detail of the design challenges and solutions for Vigilant can be found in
Ref: WFS/21/034: Vigilant – Answers to the Challenges of Forward Looking Sonar
How does it integrate with the vessel’s bridge systems?
Vigilant is designed to be operated from stand-alone or multi-function consoles on the bridge, with operator input either using a touch-screen or tracker ball. The interface to the consoles is usually via a user-supplied KVM switch.
Additionally, all Vigilant data and controls are available to external systems via a TCIP ethernet comms port. This is particularly useful for uncrewed vessels to interface to autopilots or remote control systems. Additionally, for some applications (such as manned submersibles) the user may wish to implement their own GUI. A fully detailed ICD is available on request.
Pre-designed and fully tested ECDIS integrations for some ECDIS systems are also available, allowing Vigilant data to be displayed in the ECDIS GUI.
Does Vigilant require GPS and navigation data?
Yes. Vigilant requires continuous feed from the vessel’s navigation system. This is required to enable the system to geo-reference the data and to stabilise the sensors. The necessary interface is described in the Vigilant Navigation Interface Guide, which can be provided on request.
What is the difference between Sonar and Depth Modes?
In Sonar Mode the system detects objects and the seabed at greater range and shows a sonar image but no depth information. This mode is used to provide navigational references in harbour environments and to prevent collisions when in open water.
In Depth Mode the system provides both the range and the depth information. This can be used to aid grounding avoidance and collision avoidance. In this mode the data can either be displayed as a colour coded 2D plan view or a totally customisable 3D view.
What sized object will it see at what range?
Many factors influence the system’s ability to detect objects at various ranges. The system will detect moderate-sized icebergs, submerged transport containers and whales across the whole 1500m range. Extensive studies [ref x, ref y] are available.
Ref: WFS/16/011: NOAS ICE KEEL DETECTION CAPABILITY
Ref: WFS/20/012: Vigilant FLS Whale Detection Analysis
Will Vigilant detect objects while the ship is underway?
Yes. The system is designed to see navigationally significant objects over the full range of the system at speeds of up 25kts (if bow mounted). Note that platform-related flow noise or entrained air may limit the maximum speed; Wavefront can provide advice on installation designs and acoustic window designs to minimise these effects
Does it damage or cause distress to ocean animals?
This was core to our design and influenced the power and frequency choices. Extensive analysis available in [ref] details how we are confident, based on the latest NOAA guidelines, that Vigilant will do no harm to marine fauna that may be listening in.
Ref: WFS/20/001: Assessment of Vigilant Environmental Impact
Will Vigilant see a Whale?
Yes. Not only do we know Vigilant will not harm whales we can actively reduce the likelyhood of whale injuries or ship damage by detecting whales across the full range of the system.
Ref: WFS/20/012: Vigilant FLS Whale Detection Analysis
Will it see an iceberg?
Yes. The system is capable of detecting icebergs of sizes able to cause damage to a vessel at the full 1500m range.
Analysis [ref] shows Vigilant will be able to detect small kilo-tonne sized icebergs at ranges in excess of 900m. Furthermore, it is also possible that the system will detect much smaller blocks of ice (around 1 tonne) over these ranges but with much less consistency, given the dependence of target strength on the precise geometry of the object.
Ref: WFS/16/011: Vigilant ICE KEEL DETECTION CAPABILITY
Do you need to dry dock the vessel for installation or repair?
Vigilant is designed to be either retrofitted or installed as part of a new build.
For a retro fit installation of bow mounts or through-hull deployment machines the vessel will need to be dry docked.
The system is designed to need minimal maintenance. However, if necessary, the system can be repaired without the need to dry dock the vessel. All underwater equipment is supplied with sufficient cable lengths to enable removal and refitting from a support boat (e.g. a RIB).
How should we install it? What support will Wavefront provide?
Vigilant is provided with comprehensive installation and interface specifications and is backed up by the engineering team who will provide design consultancy and review proposed designs. Sonardyne are unique in offering a range of vessel installation options, including mounting frames for installation in the vessel bow, a through-hull deployment machine, a swing-arm deployment machine, and for temporary fits, a range of over-the-bow mounting kits.
Can Vigilant be mounted on a removable device – pole or special fixing
Yes. For demonstration purposes Vigilant can be mounted to an over-the-bow deployable pole. Wavefront can supply a range of mounting kits for temporary deployments.
How deep does Vigilant have to be below the sea surface?
There is no minimum depth, but it is important that the projector and receiver arrays are mounted such that they remain fully submerged at all times during operation. This is most relevant to bow mounting, where the water line may vary with vessel speed and laden state. We would recommend the top of the projector is normally at least 1m below the design water line.
Can Vigilant be used on autonomous vessels?
Yes. The system has been mounted on a number of both autonomous underwater vessels and autonomous surface vessels. Wavefront is ready to support special installations as autonomous vessels often require bespoke integration depending on how the data will be used.
Is Vigilant Suitable for use on submersible vessels?
Yes. Our system is uniquely able to operate on vessels below the surface. We use platform depth information to automatically adjust displays as the vehicle dives. We are also able to electronically steer the vertical field of view to enable both look up and look down detection. We are able to set the caution and alert levels for both negative and positive depths relative to the vehicle .
The standard Vigilant has an operational depth rating of 30m. Depths up to 300m can be achieved on request.
Can I use Vigilant on a sailing yacht?
Yes, Vigilant is ideal for assisting sailing yachts to avoid grounding the keel when manoeuvring in shallow water. However please note that when underway under sail, vessel heel angles greater than 5-10° will begin to degrade coverage from the system. The system automatically corrects for roll (and pitch), but once the fan of beams (which is 20° in elevation) tilts too much, the beams not pointing dead ahead may no longer be intersecting with the seabed, and hence coverage will reduce.
Can it be used for diver detection or ship protection?
Yes. The system can be installed as part of a Ship Protection Sonar System (SPSS) to give all-round coverage, or can operate stand-alone in intruder detection mode covering just the field of view of the Vigilant system. The system then operates the same automatic detection and tracking software as the market-leading Sentinel IDS system, which is installed in multiple vessels and harbours wordwide.