Kraken manufactures underwater advanced sonar, laser, acoustic velocity sensors, and software for unmanned underwater vehicles used in military and commercial applications. We have developed our own line of unmanned underwater vehicles including tethered (KATFISH™) and autonomous underwater vehicles (THUNDERFISH® Alpha) as well as Autonomous Launch and Recovery Systems for these vehicles.

The Glossary below provides insight into many of key terms and acronyms associated with our industry.

3D Laser scanning2020-08-06T18:12:44-02:30

The controlled steering of laser beams followed by a distance measurement at every pointing direction. 3D laser scanning is used to rapidly capture shapes of objects and landscapes.

3D Point cloud2020-08-06T18:12:44-02:30

A point cloud is a large collection of 3D points (X, Y, Z) acquired by 3D laser scanners or other technologies to create 3D representations of existing structures.

3D reconstruction2020-08-06T18:12:44-02:30

In computer vision and computer graphics, 3D reconstruction is the process of capturing the 3D shape and appearance of real objects.


Area coverage rate. Refers to the coverage rate (usually in square kilometers per hour) in underwater surveys. A higher area coverage rate means the survey vessel and/or robot can survey a larger area, and spend less time and usually less cost performing a survey. ACR is a function of several items and involves product trade off between price, frequency, range, resolution, and speed.


Automatic target recognition refers to the ability for an algorithm or device to recognize targets or objects based on data obtained from sensors.


A component of a machine that is responsible for moving or controlling a mechanism or system, for example by actuating (opening or closing) a valve; in simple terms, it is a “mover”.


Acoustic Doppler Current Profiler is an instrument that uses sound to measure how fast water is moving across an entire water column.


Artificial Intelligence is intelligence exhibited by machines. In computer science, the field of AI research defines itself as the study of “intelligent agents”: any device that perceives its environment and takes actions that maximize its chance of success at some goal. Colloquially, the term “artificial intelligence” is applied when a machine mimics “cognitive” functions that humans associate with other human minds, such as “learning” and “problem solving”.


Autonomous Launch and Recovery Systems.


Anti submarine warfare involves the deployment of surface warships, aircraft, other submarines or robotic systems to search, detect, find, track, damage or destroy enemy submarines; or deter operations by the enemy.


Autonomous Underwater Vehicles. These vehicles in theory are underwater vehicles capable of sensing their environment and navigating without human input. In practice, they are highly automated systems, that run preprogramed routes underwater without any human input once the mission is programmed.

Autonomous vehicles2020-08-06T18:11:04-02:30

Vehicles that are capable of sensing their environment and navigating without human input.


The measurement of depth of water in oceans, seas, or lakes. Bathymetric maps look like topographic maps, which show depths by contour lines and gradient tints.

Black Smoker2020-08-06T18:13:51-02:30

Hydrothermal vents pouring hot, mineral-rich fluids from beneath the seafloor. The vents are inhabited by organisms that thrive in the absence of sunlight.


Battery management system. A BMS is an electronic system that manages a rechargeable battery (cell or battery pack), such as by protecting the battery from operating outside its safe operating voltage or temperature, monitoring its state, calculating secondary data, reporting that data, controlling its environment, authenticating it and/or balancing it.


Concept of Operations. This is a document describing the characteristics of a proposed system from the viewpoint of an individual who will use that system. It is used to communicate the quantitative and qualitative system characteristics to stakeholders.


Correlation Velocity Log. An alternative to DVL’s, Kraken developed CVL technology using advanced signal processing algorithms developed for its AquaPix® series of Synthetic Aperture Sonars. CVLs provide superior long-range navigation and high-resolution accuracy for unmanned underwater vehicles. The highly flexible and modular design allows the unit to be used in a standalone configuration or as part of an integrated navigation system.


Defense Advanced Research Projects Agency


An unmanned vehicle. Aerial drones are called UAV (Unmanned Aerial Vehicle) or UAS (Unmanned Aerial System) while underwater drones are called AUVs (Autonomous Underwater Vehicle) or UUV (Unmanned Underwater Vehicle)


Doppler Velocity Log is an instrument used to measure a vehicle’s velocity relative to the seafloor in water. As GPS does not work underwater, other methods of navigation are required. DVLs are deployed on underwater vehicles such as ROVs and AUVs for navigation and guidance.


Forward Looking Sonar


Fiber optic gyroscope. A device that senses changes in orientation


The science of surveying and charting bodies of water, such as seas, lakes, and rivers.


A sonar receiver functioning by transforming underwater sound signals (pressure waves) into electrical signals. In side scan sonar, the functions of the hydrophone and projector are performed by one transducer (active sonar). Often a hydrophone is a passive device doing no transmitting on its own. Hydrophones are commonly used to receive seismic echoes from explosive devices or other low frequency acoustic signals. In these applications, hydrophones are placed in “streamers” or long flexible tubes and towed behind survey ships for deep sub bottom imaging.


Inspection, Maintenance, Repair. Refers to the inspection, maintenance and repair of subsea facilities and installations.


Inertial measurement unit is an electronic device that measures and reports a body’s specific force, angular rate, and sometimes the magnetic field surrounding the body, using a combination of accelerometers and gyroscopes, sometimes also magnetometers.


Inertial Navigation System. An INS is a navigation aid that uses a computer with a Kalman filter, motion sensors (accelerometers) and rotation sensors (gyroscopes) to continuously calculate via dead reckoning the position, orientation, and velocity (direction and speed of movement) of a moving object without the need for external references. It is used on vehicles such as ships, aircraft, submarines, guided missiles, and spacecraft. Other terms used to refer to inertial navigation systems or closely related devices include inertial guidance system, inertial instrument, inertial measurement units (IMU) and many other variations. Inertial Navigation is used where GPS is not accurate or not available.


Generally used to describe swath-sounding sonar techniques that use the phase content of the sonar signal to measure the angle of a wave front returned from a sonar target.


Intelligence, Surveillance, Reconnaissance


International Traffic in Arms Regulations. ITAR is a set of United States Government regulations on the export and import of defense- related articles and services.


Launch and Recovery System. Mechanical and electrical systems used to deploy and recover ROVs, AUVs, and subsea drills used in offshore applications.


Low frequency SAS


A surveying method that measures distance to a target by illuminating that target with a pulsed laser light, and measuring the reflected pulses with a sensor.


Life of Field. Refers to the assurance of asset integrity throughout the operational life cycle of subsea oil and gas assets, enabled by a suite of services from offshore service providers.

Machine Learning2020-09-17T15:40:43-02:30

A subfield of computer science that gives machines the ability to learn without being explicitly programmed.


Mine countermeasures. Technology designed for the location of and destruction of naval mines and underwater IED’s


Multi-beam Echo Sounders refers to a type of sonar that is used to map the bathymetry of the seabed. MBES sonars are downward looking and use many individual beams to identify bottom depths for 3D bathymetric mapping. Side Scan Sonars are side looking and are used to image the seabed for use in identifying sea bed characteristics, inspection of subsea assets, or looking for objects.


Sonar signals arriving at a target, or the towfish, from a single source but along different paths. In the sonar sciences, multipath echoes can be problematic. Multipath returns in imaging sonar typically occur in shallow water or around complex structures such as petroleum platforms or near piers and pilings. A classic multipath environment for side scan sonar is in shallow water with a flat sea surface.
Nadir gap – Refers to the acoustic “gap” located directly underneath an AUV platform, which is a product of the side-looking sonar system.


National Oceanic and Atmospheric Administration

Passive Sonar2020-09-17T15:44:39-02:30

A sonar system having only a hydrophone and capable of receiving signals but not transmitting them. An example of a passive sonar is a streamer array towed from a seismic vessel. Another is an array on a submarine that detects other vessel’s engine and propeller noise.


Post mission analysis. Kraken RTSAS, Real Time SAS Processing drastically reduces post mission analysis time by processing the SAS data onboard the vehicle as the mission is run. This alleviates the requirement for lengthy processing once the AUV has returned, and allows operators to instantly view full resolution, georeferenced SAS data.

Polymetallic nodules2020-09-17T15:50:07-02:30

Also called manganese nodules, these are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. The core may be microscopically small and is sometimes completely transformed into manganese minerals by crystallization.


Sonar data processing after real time data generation and storage. Modern sonar systems allow the user to concentrate on the task at hand of gathering data by recording “raw” data which can be manipulated or “processed” later. Because ship time is expensive and operational crews must be fully attentive to proper data gathering, post processing is most effectively performed in the less time-budgeted environment of the on-shore laboratory. Post processing can include mosaic construction, slant range and speed correction, false colorization and hard copy print generation.

Predictive Analytics2020-09-17T15:53:35-02:30

Predictive analytics encompasses a variety of statistical techniques from predictive modeling, machine learning, and data mining that analyze current and historical facts to make predictions about future or otherwise unknown events. Predictive analytics will increasingly be used in underwater asset inspection and maintenance applications.


Rapid Environmental Assessment.


The interdisciplinary branch of engineering and science that includes mechanical engineering, electrical engineering, computer science, and others.


Remotely Operated Vehicle. This is an underwater vehicle that is connected to an operator via power and/or communication tether. ROV categories include work class, inspection class, or observation class.


Remotely operated tow vehicle


Robotics as a service. Refers to an offering where AUVs can be deployed and data delivered to the customer as a service as opposed to the customer having to own, deploy, and maintain the data collection asset (i.e. AUV)


A sonar setting which represents a distance, usually measured in metres, that is the maximum distance from the towfish or AUV that the sonar will display (the range setting on the sonar also determines the time between outgoing sonar pulses); also synonymous with the cross-track dimension. Once the range setting on the system is set, when returning echoes arrive from that distance away from the transducer, the ping cycle starts again and a new acoustic pulse is transmitted in to the water.


Real Aperture Sonar. The sonars aperture is the actual length of the receive array.


Synthetic Aperture Sonar. SAS is a form of sonar in which sophisticated signal processing of sonar data is used to “synthesize” an artificial aperture up to 10-25x longer than the real, physical aperture length. The result is ultra high definition images and increased range, resolution and ACR as compared to real aperture sonar. SAS is analogous to synthetic aperture radar (SAR).


Sub bottom imaging. A technique using multi-beam, low frequency sonars combined with synthetic aperture sonar software to generate a fully three-dimensional view of the layers of sediment or rock under the seabed. SBI can be used for detecting and classifying buried objects (such as unexploded ordinance, underwater explosive mines, buried pipelines or buried cables). SBI provides superior resolution and a full 3D image compared to the lower-resolution and 2D profile of an SBP


Sub bottom profiling. A technique using single-beam, low frequency sonars which is employed to identify and characterize layers of sediment or rock under the seafloor. The single-beam provides a one-dimensional view of the layers of seabed below. The second dimension is provided by moving the SBP system forward.


Side scan sonar. A specialized system for detecting objects on the seafloor. Most side scan systems cannot provide depth information. Like other sonars, a side scan transmits sound energy and analyzes the return signal (echo) that has bounced off the seafloor or other objects.

Swath Width2020-09-17T16:04:19-02:30

The lateral coverage of side scan sonar on the seabed. Because side scan sonar projects a beam out to the side of the towpath it creates a wide region of insonified seafloor. Both right and left sonar channels make up the swath. Swath width changes with range settings and is a factor in determining coverage and lane spacing.


The electromechanical component of a sonar system that is mounted underwater and converts electrical energy to sound energy and vice versa. The transducer formation determines the beam shape and is the basis for image formation in side scan sonar. Its condition and stability help determine the final image quality. Transducers can be surrounded by various types of acoustically transparent urethanes or epoxies, or can be within an oil-filled assembly. For the purposes of side scan, transducers are almost always mounted on a towbody which also contains firing and amplifying circuitry. They are towed over a cable instead of hull mounted in order to maximize stability by de-coupling them from ship motion.


Typically used to refer to command and control, or processing electronics, for subsea sensors and vehicles, that reside onboard the ship (above water).


A tethered or towed UUV that has a constant power and data connection to the support ship. Towbodies do not require batteries like AUVs.


Refers to the cloudiness or haziness of a fluid caused by large numbers of individual particles that are generally invisible to the naked eye, similar to smoke in air. The measurement of turbidity is a key test of water quality.


Ultra short baseline is a method of underwater acoustic positioning. A complete USBL system consists of a transceiver, which is mounted on a pole under a ship, and a transponder or responder on the seafloor, a towfish, or on an AUV or ROV. A computer, or “topside unit”, is used to calculate a position from the ranges and bearings measured by the transceiver.


Unmanned maritime vehicles are broken into two categories: UUVs and USVs


Unmanned underwater vehicles sometimes known as underwater drones, are any vehicles that are able to operate underwater without a human occupant. There are two categories of UUVs: AUVs and ROVs.


Unmanned surface vessels are vehicles that operate on the surface of the water without a crew.


Unexploded ordinance. Refers to unexploded bombs, shells, grenades, land mines, and naval mines that did not explode when they were employed and still pose a risk of detonation, sometimes many decades after they were deployed.


Extra large UUV. The US Navy envisions the XLUUV as a modular, open architecture system that can be reconfigured with different payloads. The vehicle will be able to be launched pier-side without needing to be carried aboard a host ship. The XLUUV will differentiate itself from current submersible systems by its greater endurance and payload capacity, including the potential to perform offensive manoeuvres while submerged underwater.

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