Demystifying the Deep Sea: Lighting Up the Ocean’s Darkest Corners

In this feature Luke Richardson, VP of Sales & Marketing for Voyis, a Covelya Group company, explores the innovative platforms and technologies that are enhancing deep water exploration to better understand the ocean’s deepest and most mysterious regions.

In a recent UNESCO article, it was estimated that just five percent of the ocean has been explored and charted by humans and, with the ocean covering more than seventy percent of the earth’s surface, this leaves the majority of our planet unexplored. With a huge, untapped potential resource for environmental, geological, and even commercial resource, finding ways to explore the ocean safely and with minimal environmental impact has been challenging.

With as much as 11km of water overhead, the only truly safe and efficient way to explore these areas of the world is through robotics platforms, including remotely operated vehicles (ROVs) and autonomous underwater vehicles (AUVs).

Sensors: the ‘Brains’ of Robotic Systems

It is evident that ROVs and AUVs are enabling humans to access the deep with the highest degree of safety, and depending on the operation, with a greater reduction in environmental impact. However, when using these platforms for operations deep in the ocean, there is a critical reliance on high-quality, high-performing sensors onboard to ensure that this type of expensive equipment comes back safely and with usable data. While the mechanics of the vehicle is a continuing challenge which vehicle manufacturers are owning, there is another aspect to consider – that is the ‘brains’ of the mechanical interface. In other words, the sensors, and capabilities that all need to complement one another and work together to allow the platform to operate efficiently and effectively.

Taking on the role of a ‘sensor prime’, Covelya Group is well placed to ensure ocean robotics can perform optimally in the harshest of environments. Through delivering core essentials including navigation, communication, mapping, monitoring, and data amalgamation/interpretation with vehicle automation software, the companies within the Group provide a synergistic, cohesive solution for improving subsea platform operations together.

Navigation: Understanding Where We Are

Effective subsea missions start and end with reliable and accurate navigation. Operating deep in the ocean, vehicles don’t have the luxury of utilising GPS, and so pinpoint accuracy in navigation is vital. One Covelya Group company that has taken this challenge head on is Sonardyne International, bringing forward their expertise in subsea navigation and communication with over 50 years of experience. Within Sonardyne’s product portfolio, there is a network of combined capabilities that offer best-in-class performance for subsea position and tracking to ensure successful operations. These systems include the SPRINT-Nav line of co-located inertial navigation system (INS) and Doppler velocity log (DVL) for high-precision navigation, 6G ultra-short baseline (USBL) with AvTrak6 vehicle mounted transceiver for simultaneous long-baseline (LBL) ranging, USBL tracking via a surface vessel and robust telemetry for subsea vehicle to vessel and AUV-to-AUV communications, building a complete network of systems defining underwater position.

When deploying autonomous platforms, one other critical element of successful navigation subsea is utilising sensors that enable accurate obstacle avoidance. Where Sonardyne’s suite of navigation sensors provide the foundation for platform navigation, systems like Wavefront’s Vigilant Forward-looking sonar (FLS) and Voyis’ Discovery Stereo Vision Systems can provide further input into the entire navigational story for robotic platforms through delivering real-time perception of new or uncharted areas of the ocean. For larger AUVs, Wavefront’s Vigilant forward-looking sonar provides real-time 2D or 3D sonar images of the seabed and water column ahead of the AUV with up to 1500m of hazard detection, enabling reactive navigational autonomy on wide area surveys.

Alternatively, Voyis’ Discovery Stereo Vision Systems deliver extremely detailed localised perception through real-time millimetric 3D point cloud depth maps to offer robotic systems with finer visual navigational capabilities through perception of objects within 5m of the platform, for confident manipulation, docking, or inspection operational objectives. As a compact solution, Discovery is suitable for a wide range of vehicles including smaller AUVs and ROVs.

Complementing the core fundamental navigation performance delivered by Sonardyne’s suite of inertial and acoustic sensors with both Wavefront’s FLS and Voyis’ optical depth perception can equip robotic systems with a cohesive capability for confident, safe, and efficient expeditionary missions.

Communication: Listening to the platform

Communicating with the subsea robotic platform, particularly autonomous systems, is also crucial to be able to plan, control and navigate these assets on the ocean floor. Communications underwater are especially challenging due to the laws of physics; radio and satellite communication signals are limited in that they are only able to penetrate a few centimetres of water.

Acoustic communications is fundamentally limited by how acoustic rays propagate in varying waters with temperature and salinity gradients acting to bend and distort signals. Improved signal processing means more reliable acoustic communications are now possible, and the speed of data transfer has improved, where the physical channel allows.

Sonardyne’s fast and robust 9,000 bps acoustic communications performance means subsea vehicles can communicate to topside vessels via beacons at up to 11km, enabling unmanned vessels to undertake challenging location explorations whilst still being able to relay information back to a surface vessel.

This communication capability can be implemented both in a surface-to-AUV model as well as an AUV-to-AUV model, essentially creating swarms that can undertake extensive exploration whilst communicating and sharing relevant data across the entire fleet.

Monitoring and Mapping: Generating a Greater Perception of the Ocean

The Ocean Decade acknowledges that we will have a continuing need for use of the ocean, our seas, and marine resources but we cannot change how we use them without better scientific understanding of them. Environmental sensing and mapping the subsea ecosystem with extreme accuracy and detail is becoming an integral part of any deep-sea mission, fundamentally allowing humans to generate a complete digital representation of the environment and expanding our understanding of the unknown. Chelsea Technologies, Wavefront, and Voyis have developed capabilities that complement one another in providing a full perception of the darkest corners of the ocean using fluorometry, multi-aperture sonar technology, and laser scanning with optical imaging systems.

When considering mapping objectives of the physical terrain subsea, acoustic and optical sensors can work together to give users a more complete understanding of the underwater world. Wavefront’s Solstice multi-aperture sonar captures wide area swaths in a high-enough resolution to identify shipwrecks, aeroplane wreckage and even threats in the ocean. Once possible points of interest have been identified and further investigation is required, high-resolution laser scanners and cameras can be used for areas that need to be revisited to be inspected in more detail.

Multi-aperture sonar can achieve incredible coverage rates, mapping over 200m on each side of the vehicle, allowing for efficient detection and classification of objects on the centimetric scale. Conversely, optical sensors, like 3D laser scanners and stills cameras, can provide highly detailed quantitative and qualitative datasets for extremely accurate, millimetric, identification of localised areas using a maximum scanning range of 15m. To achieve both coverage and resolution, the sensors and vehicles must work together as a tightly integrated system, with acoustic sensors first detecting features of interest and then optical sensors reacquiring the target for assessment with higher resolution data.

Delivering a stronger understanding of a subsea ecosystems from robotic systems require sensors that can deliver increased fidelity of data quality. Stills images captured by Voyis’ cameras are not just high-resolution but are also optimised for photogrammetry. Photogrammetry is a powerful capability that enables 3D models to be created from 2D images. By utilising edge computing to correct image lighting, colour, and distortions in real-time onboard the vehicle, photogrammetry software can be efficiently used to analyse the position and orientation of the stills images and create a complete colorised model of the underwater scenes. These not only provide a virtual representation of underwater structures, but also generate a comprehensive digital twin of a subsea environment to monitor changes over time.

There are a multitude of reasons driving greater exploration of our oceans. Building a broader knowledge of the ocean floor and potentially discovering new species, as well as environmental and climate research are large motivators.

Furthermore, delivering environmental monitoring capabilities beyond the physical geometry and visual aspects within a subsea domain can help humans interpret and learn more about the ecosystem and behaviours in substantially greater detail. Chelsea Technologies’ STAF (Single Turnover Active Fluorometry) measures phytoplankton photosynthesis in the ocean, which is at the very start of life cycles in the ocean. Alongside classical fluorometry, this technology can monitor levels of turbidity and water quality, helping in the exploration and monitoring of the impact of climate change and human activity on the world’s oceans.

Combining all these elements supported across the Covelya Group; navigational, communications and environmental monitoring, subsea vehicles can build an entire vision of the ecosystem in the ocean, not just the physical based space, but current environmental and future resource.

Software: Making Sense of the Data

The final piece that ties these capabilities together is software which can take all the sensor inputs and blend them together to create a complete picture of the subsea domain. It can help with mission planning for the vehicles, interpret the results onboard the vehicle and enable tracking and following of features.

EIVA a/s, innovative software developers with capabilities advancing survey operations, data automation, and vehicle autonomy, provide software capabilities using inputs from Chelsea Technologies, Sonardyne, Voyis, and Wavefront sensors to fast-track data deliverables and improve underwater vehicle effectiveness. EIVA’s NaviSuite is the cornerstone for survey operations, amalgamating datasets across a wide array of sensors mobilised on robotic platforms, offering live data quality controls measures, and enabling analysis capabilities to interpret results in real-time through deep learning. Real-time data interpretation unlocks vehicles to perform adaptive missions, or corrections, based on direct input from the sensors onboard the vehicle and EIVA’s interpretation of the results, streamlining the entire data process.

Furthermore, complementing sensor technology with EIVA’s software packages can deliver robust, vehicle autonomy capabilities. Deploying the suite of navigation and mapping sensors identified earlier, EIVA’s software allows the sensors to provide direct feedback to a vehicle’s mission, including pipeline or cable tracking, or executing specific autonomous operations and inspection patterns.

It is through this symbiotic relationship between sensors, software, and platform, that Coveyla Group technology can deliver a truly synergistic approach to enabling deep water operations. As with any technology, the value is not only with the capture of data, but its extraction and the ability to analyse the findings to apply real, beneficial change.

Exploring the Ocean Together

Within this context, Covelya Group’s Sonardyne, EIVA and Voyis, demonstrated the effectiveness of collectively developing a complete offering for subsea platforms by leveraging individual expertise in sensing and software domains for a common objective, bringing to light the greatest detail of the depths. By joining forces, these three entities unlocked the capability to find, navigate to, and construct a comprehensive 3D model of archaeological significance. Their collaborative efforts extend into the realm of history, as demonstrated by the recent discovery of Sir Ernest Shackleton’s legendary ship, Endurance, in the depths of Antarctica. Sonardyne, EIVA and Voyis were integral to the expedition, assisting in the creation of a digital twin of the wreck of this famous vessel.

Greater than the Sum of its Parts

The foundation on which subsea vehicles’ success is built are the sensors and the software that work together to generate a common goal. The physical vessel must be strong and able to withstand the incredible pressures at depth, but real value lies within the ‘brains’ of the vehicle – capabilities that come from the intelligent features and systems onboard.

With multiple requirements and several potential system solutions, the ability to combine Covelya Group’s total capability brings about not only cost efficiencies, but also cohesion of technology. This enables Covelya to be vehicle agnostic and lead the charge for autonomy and deep-sea exploration through working on complex operations together. Working in tandem, Covelya Group can create a full solution for any ocean industry requirements.

For the past four decades, technology has been central to measuring and interpreting the ocean environment. If we are to make the Ocean Decade more meaningful to wider society, we need to continue to innovate by making technology more capable. That is why, as a Group, we will continue to innovate, supporting the exploration of our world’s oceans and waters and work towards a safe and sustainable future.