Hydro International visits Exail in La Ciotat

The new DriX O-16, produced by Exail, was christened this summer in a ceremony attended by many officials, customers and co-workers in the harbour of La Ciotat. The transoceanic DriX O-16, the latest addition to the DriX series of unmanned surface vehicles (USVs) produced by the French company, was introduced to the public at Oceanology earlier this year. Hydro International had the opportunity to watch the DriX in action – under almost ideal circumstances – in La Ciotat bay and was given a tour of the DriX production facility at the naval yard of its home base on the Mediterranean.

The tour included a sneak peek in the yard control room, with DriX USV operations manager Olivier Moisan. Hydro International also had the opportunity for an in-depth talk about the new Sams 150 synthetic aperture sonar with Baptiste Marty, project manager and algorithm engineer in Exail’s sonar division. Here we report on a visit to one of the leading companies in the field of maritime, defence and aerospace technologies, made up of a team of dedicated, forward-thinking and enthusiastic professionals.

The highlight of the visit to La Ciotat was of course the christening of Exail’s new USV. This latest addition to the French company’s portfolio is the largest DriX so far – at 16 metres – and differs from family members in its improved sea handling and high sensor integration capacity. It is also transoceanic; it can run 30 days non-stop, travelling up to 3,500 nautical miles. The USV can launch AUVs, ROTVs and ROVs and has dual hybrid propulsion, with an extremely efficient combustion engine. The O-16 is specifically designed for deep-water hydrography, making it a potential game-changer for survey and seabed mapping. Its advanced capabilities can accelerate project timelines and expand the scope of work, even in challenging environments and remote locations. By optimizing operations, the O-16 enables teams to complete projects with fewer people in the same time frame.

The ceremony in the harbour was led by Sébastien Grall, director at Exail in La Ciotat. Grall explained that the new DriX was an evolution, based on the architectural concept of its little brother, the smaller DriX-H8, but designed for longer exploration missions further afield, capable of crossing oceans even in adverse weather conditions and equipped with artificial intelligence. The new DriX can also carry payloads such as echosounders, autonomous robots, seabed profilers and sonars. During the facility tour, Grall explained that the new DriX addresses a critical gap in the survey market. It is particularly suited for missions in remote and challenging conditions, where skilled personnel are often scarce – particularly in survey and mapping. Because the DriX is produced and assembled according to customer wishes at the yard, it is highly versatile. Specifications are flexible and can be adjusted at any time to meeting project requirements. Exail maintains a line of DriX ready to be kitted out, to keep delivery times short when needed. Furthermore, the company provides direct help for any problems with one of the USVs that cannot be solved by the customer. Olivier Moisan, DriX USV operations manager, showed how, from mission planification to execution, the software interface provides the operator with the right level of information, allowing the team at the control room in La Ciotat to solve almost any problem from a distance.

Back to the ceremony: Grall received help from an Exail employee’s daughter to smash a bottle of champagne over the DriX’s hull and cut the ribbon, marking the end of the official christening and followed by an informal meeting with many toasts to the prosperous development of both DriX and Exail.

Easy-to-use combination of technology: Sams 150 synthetic aperture sonar

On the fringes of the festivities and during the tour of the facilities, Hydro International spoke to Baptiste Marty, product manager and algorithm engineer for Exail’s synthetic aperture mapping sonars (Sams) series. According to Marty, the new and dedicated release, the Sams 150, combines the advantages of ease-of-use of a sidescan with the high-quality resolution of synthetic aperture sonar (SAS) by relying on inertial navigation systems to compensate platform motion, producing high-quality imagery. The Sams 150 is especially aimed at the survey sector, with a massive increase in covered areas compared to standard sidescan sonars, and almost no post-processing required. Marty explains: “By having a natively georeferenced processing frame, we relax the platform movement constraints on attitude variation. We also want to provide multiple processing algorithms to be able to use the Sams 150 in many different operating scenarios, whether as a regular synthetic aperture sonar or more like an enhanced sidescan sonar.”

What are the main advantages of the Sams 150?

“We have a target SAS resolution of 6 x 2.5 centimetres. Our goal is to design an SAS for the survey industry that does not always require very high-resolution. When it comes to system engineering, the higher the resolution you want to achieve, the more complex the system will be and the more challenging to operate. This is the trade-off. The natively georeferenced reconstruction algorithms provide real-time output data that is easy to use, eliminating the need for post-processing. And, we don’t have a massive image quality gap between real-time and post-processing, though you can choose the latter – for instance to clean up soundings or smoothen a bit. This is really what we want to achieve here.”

What was the customer feedback after initial experiences with the system?

“We’ve carried out a few surveys now with clients and we assisted them a lot during those first experiences. All in all, they were pretty satisfied. Usually, you have to plan your survey well ahead, otherwise the quality of the data can deteriorate quickly, for example due to heading changes or improper altitude relative to the seabed. But with Sams technology, higher heading changes as well as roll and pitch movements are possible because of the much broader beam. It’s almost like you can just put it in the water and acquire qualitative data whatever happens.”

So can anyone be a hydrographer now, if it’s so easy to use and almost ‘guarantees’ good data whatever the circumstances and planning?  

“Data processing becomes more democratic. I think that’s a good thing, as it makes the processing faster and easier, but we should also keep in mind that we still want to provide insight into the process, whether it is data acquisition or image reconstruction. The output format that we provide is directly georeferenced mosaic images through proprietary processing. Our goal is to offer plenty of quality metrics to the hydrographer and the end customer, to assess the quality of the data. We can provide average signal to noise ratio, ping density per sounding, or estimated resolution criteria. That way, the user has some metrics to be able to make a good estimate of the quality of the sonar and output data, despite the processing remaining a black box and the user having to take the outcome for granted. But I believe that’s also part of the adoption of new technologies.”

What more can you tell us about the Sams 150?

“A nice feature of this sonar is that it has a built-in interferometric capability. This means that, in this array, we have two antennas stacked on top of one another, which enables us to generate the best bathymetry maps. For example, they have very high area coverage rates compared to traditional multibeam echosounders. The system is designed for the survey industry, but we can envision multiple other users, such as search and rescue, habitat monitoring, archaeology, oil and gas, and critical subsea assets inspection.”

Where do you expect the biggest growth?

“Obviously the survey industry, but also scientific institutes or navies that want to pursue seabed exploration. One big area of development for SAS technology will be those deeper areas of the continental shelf, let’s say beyond a kilometre depth. Cable inspections are also a good growth opportunity for SAS – you only have to think about recent events in the Baltic.”