Kraken Robotics Inc. announces that its wholly owned subsidiary, Kraken Robotic Systems Inc., is developing an ultra-wideband acoustic remote sensing system for seafloor imaging and mapping.
The AquaPix® Multispectral Synthetic Aperture Sonar (SAS) will be the world’s first commercial SAS to operate over such a wide spectrum, ranging from low audible frequencies to high ultrasonic frequencies.
Oliver Plunkett, CEO of Ocean Infinity, said, “The true value in seabed mapping is in the operational efficiencies that are achieved by our clients through rapid processing and intelligent analysis of the data we collect. For us, and for our clients, that means that any improvement in the quality of that data is of significant interest. In the future we expect to see simultaneous autonomous data processing with the relevant results passed directly to the customer. An approach that puts more of the processing onboard the AUV and generating seabed imagery, maps and 3D digital terrain models in near real time is a big step on the path to that future. The possibilities that the latest in sensor and data analytics technology Kraken’s AquaPix® Multispectral SAS represents are very exciting and we look forward to working with Kraken through this next stage of development.”
In summary, there are three notable benefits of this new technology:
Karl Kenny, President and CEO of Kraken, said, “The AquaPix® Multispectral SAS is a true gamechanger in underwater sensors and will be ideal for a wide variety of seafloor imaging and mapping applications. At Kraken, we strive to foster a culture of innovation and collaboration within our development teams to gain fresh perspectives and further inspire our people to continue to advance the boundaries of underwater sensors and robotics. This new sonar is pushing the frontiers of underwater acoustics and we expect it will be in high demand across the entire digital ocean economy. We are very pleased that Ocean Infinity will help us launch this very innovative product.”
SAS is a powerful imaging technique that coherently combines echoes from multiple acoustic pings along the trajectory of an underwater robot to construct a “synthesized” sonar array. When synthetic aperture techniques are applied at sufficiently low acoustic frequencies, a modest-sized SAS can generate imagery with a constant azimuth resolution comparable to that of higher frequency sonar systems, but with significantly longer range. SAS systems are now being fielded in a wide range of military and commercial applications including underwater surveys, habitat mapping, oil and gas, environmental monitoring, marine archaeology, inspection of submerged structures, searching for downed aircraft and naval mine countermeasures.
Multispectral satellite and airborne remote sensing, acquiring data from the electromagnetic spectrum, has enabled scientists to map terrestrial features for many years. However, the limited penetration of electromagnetic radiation through seawater renders satellite and airborne remote sensing impractical for mapping the seafloor in all but the shallowest of waters. In practice, acoustic remote sensing systems are required to map the ocean floor.
Over the past number of years, multibeam sonar systems have come to dominate the world of marine survey. However, to meet the competing needs of range performance versus resolution, most of these systems only operate at a single frequency (or a very narrow band of frequencies) at any one time. As a result, the seabed and volume scattering products are essentially monochromatic and are typically displayed as a single colour image, representing a single data point for each bottom location. In contrast, Kraken’s AquaPix® Multispectral SAS collects multispectral data at several frequency bands widely spaced from 5 kHz to 200 kHz. The broadband SAS provides much more data with significantly improved range and resolution.
Dr. Alan Hunter, an internationally recognized SAS expert, is collaborating with Kraken on the development. Dr. Hunter said, “Kraken’s AquaPix® Multispectral SAS will provide an exciting new capability for mapping and understanding the seafloor. By analyzing the relationships between acoustic signals scattered at different frequencies and aspects, it will be possible to infer the material properties of the seafloor and the objects resting upon it. Furthermore, the lower frequencies will penetrate the seabed to reveal buried features and objects to reveal their internal structures. The lower frequencies will also enable longer detection range when the Multispectral SAS is deployed in deeper waters and operated in a side-looking configuration.”
Dr. Craig Brown, NSERC Industrial Research Chair in Integrated Ocean Mapping Technologies at Nova Scotia Community College said, “The development of Kraken’s AquaPix® Multispectral SAS is an exciting and innovative opportunity to improve the way that we map seafloor geology and benthic habitats. Combining multiple frequencies in this way offers potential opportunities for improved habitat discrimination and classification. The application of broadband multispectral backscatter in acoustic remote sensing offers significant advantages and the benefits of this approach to seafloor mapping are potentially ground-breaking.”
Other uses for multispectral SAS relate to the study of hydrothermal vents and hydrocarbon seeps. Scientists now recognize that there are many hundreds of vents and thousands of seeps in deep water. These chemosynthetic communities interact with surrounding ecosystems on the seafloor and water column and affect global geochemical cycles. The importance of understanding these interactions is growing as the potential rises for disturbance of the systems from oil and gas extraction, seabed mining and bottom trawling. As deep-sea mining of hydrothermal vents for copper, zinc, lead, gold, and silver becomes a reality, many questions remain regarding the dynamics of these ecosystems, and what it could mean for the ocean to lose them. While less visible, the risk to the methane seep communities that colonize nearly all the world’s continental margins has escalated from increased bottom trawling activity and oil and gas drilling in deep waters. Understanding how humans impact these ecosystems is needed for environmental management and protection.
Dr. John Jamieson, Canada Research Chair in Marine Geology at Memorial University said, “As resource exploration increases in the deep sea, there is a growing requirement to understand the distribution of resources as well as ecosystem functions and services that may be vulnerable to such activities. Having observations of the same seafloor at different acoustic wavelengths allows for increased discriminatory power in seabed classification and characterization efforts. The development of systems with multispectral backscatter capabilities is an excellent opportunity to improve the way that we segment, classify and map seafloor geology. We look forward to working with Kraken to objectively assess how the seabed backscatter intensity from their Multispectral SAS can provide information about the geologic materials on the seabed based on their acoustic properties.”
Naval mines are a threat that will be present in the future, and therefore, new techniques such as multispectral acoustic remote sensing are needed to detect these weapons that wait.
Designed to improve target detection, increase area coverage rate and reduce false contacts, Kraken’s AquaPix® Multispectral SAS operates over a wide range of wavelengths and aspects: where centimeter-scale wavelengths are used for fine-detail imaging of the seabed and small objects that lay proud on it; and longer wavelengths, which can propagate deeper into the sediment volume, are used for imaging and analysis of both proud and buried objects.
Kraken’s AquaPix® Multispectral SAS is the first commercial ultra-wideband sonar that combines techniques for high-resolution imaging and target analysis, automated target recognition and seabed change detection and advanced autonomy via situational awareness provided to the host platform by the sensor.
Prototype production has commenced, and commercial availability is expected in 2019. Pricing for a complete system, including downward and dual side looking arrays with real time signal processing and 3D mapping engine is expected to be under US$1 million.