The First All-Canadian Antarctic Expedition Uses Galileo HAS and Eos GNSS to Map Underwater Features

Antarctica’s vast expanse stands as one of Earth’s last true frontiers, harboring some of the richest potential for scientific discovery.

In February 2025, that potential brought together 15 Canadian scientists from across the country for a historic undertaking: the first all-Canadian Antarctic research expedition.

The month-long journey across the South Shetland Islands and the northern Antarctic Peninsula focused on interdisciplinary research covering climate change, coastal geology, and oceanographic processes. Experts from Canadian universities and government agencies collaborated to advance research contributing to the global understanding of Antarctica’s changing environment.

Leading the expedition’s mapping efforts was Ocean Mapping Group Research Scientist Kevin Wilcox. Ocean Mapping Group, founded in 1991 at the University of New Brunswick (UNB), focuses on developing innovative techniques and tools for the management, processing, visualization, and interpretation of ocean mapping data. As part of UNB’s Department of Geodesy and Geomatics Engineering, the group brings together experts in hydrography, geographic information systems (GIS), and 3D visualization.

A variety of underwater features — including a glacial lagoon, ancient sunken beaches, and even a submerged volcanic caldera — required detailed mapping to identify and study geological changes over time. Wilcox was well prepared for the challenge.

The Challenge: High Accuracy in Harsh, Remote Conditions

All Aboard the HMCS Margaret Brooke

The team’s home base for the expedition was His Majesty’s Canadian Ship (HMCS) Margaret Brooke, a Royal Canadian Navy (RCN) vessel. However, unlike many research ships, the Navy vessel lacked the specialized equipment required for ocean floor mapping.

“In a lot of expeditions, our ships often have a sonar system on board for mapping capabilities,” Wilcox said. “But because we were on a Navy vessel, this ship wasn’t equipped with full multi-beam sonar capabilities. That is why I was brought on the team.”

To provide the sonar capabilities they needed, Wilcox planned to deploy a small, unmanned survey vessel (USV) equipped with a multibeam sonar system to capture detailed underwater topography at each survey site. But to accurately position and orient each sonar ping, he needed high-accuracy global navigation satellite system (GNSS) technology.

Wilcox needed GNSS positioning that would work in a remote area — surrounded by a vast ocean — with no real-time kinematic (RTK) base stations in sight. When he learned about Europe’s new Galileo High Accuracy Service (Galileo HAS), he immediately saw the potential.

“There aren’t any RTK networks in Antarctica. That sent us looking for the Arrow Gold+ and Galileo HAS corrections. When we found these, we realized we had a possible solution.”

— Kevin Wilcox, Research Scientist, Ocean Mapping Group

The Solution: Galileo HAS and Eos Arrow Gold+

Galileo HAS is a relatively new, satellite-based worldwide correction service from the European Union, still in its deployment phase. Offering free real-time corrections directly from the Galileo satellites, it delivers horizontal accuracy better than 20 centimeters with 95% confidence after convergence. In remote regions like Antarctica, this service provides a revolutionary opportunity. But it requires a compatible GNSS receiver on the ground.

Wilcox learned about the Canadian-made Arrow Gold+^® GNSS receiver from fellow UNB colleague Richard Langley. The Arrow Gold+, made by Montreal-based Eos Positioning Systems^®, was the first GNSS receiver compatible with Galileo HAS, and as such it offered a unique advantage for high-accuracy mapping in remote environments.

“There aren’t any RTK networks in Antarctica,” Wilcox said. “That sent us looking for the Arrow Gold+ and Galileo HAS corrections. When we found these, we realized we had a possible solution.”

All (Technology) Aboard! The “R/V Frequensea”

Wilcox equipped a small Seafloor Systems Echoboat-160™ USV (affectionately dubbed the “R/V Frequensea”) with Kongsberg M3 Sonar^®, a multibeam sonar system. The sonar emitted sound waves in a wide swath — about 60–70 degrees to either side — and recorded how long it took for the signals to bounce back from the seafloor. Each sonar “ping” captured depth data at 256 different points, forming a detailed image of the underwater terrain.

Beside the sonar head, Wilcox installed a sound velocity sensor to continuously measure the rate at which sound traveled through the water. Sonar calculates distances by soundwave timing, meaning that variations in sound speed can cause positioning errors unless corrected, especially near the sonar transducer.

To accurately georeference the sonar scans, Wilcox added two critical components aboard the USV. First, the Coda Octopus F180^® inertial measurement unit (IMU) continuously tracked the USV’s orientation as it pitched and rolled through the rough Antarctic waves. Second, the Arrow Gold+ GNSS receiver maintained accurate positioning by providing 10-20 centimeters of 3D accuracy when using satellite-based Galileo HAS corrections.

“Ten to 20 centimeters was quite good, all things considered. After all, you are at the bottom of the Earth!” Wilcox said. “The vertical accuracy was especially important for our bathymetric work. Any vertical error would directly add error to our depth.”

Wilcox also equipped the USV with a Velodyne^® VLP-16 terrestrial LiDAR sensor to capture shoreline data. Like the sonar scans, the LiDAR required positioning information from the IMU and Arrow Gold+ GNSS receiver to translate angle and range measurements into accurate coordinates. While shoreline data collection was not the primary focus of the expedition, it was performed to support other research aimed at identifying raised beaches (i.e., areas that indicate former shorelines when water levels differ).

The last key piece of technology aboard the USV was an autopilot system called Seafloor AutoNav^™. This autopilot allowed Wilcox to predefine waypoints, so the vessel could navigate and pilot itself autonomously along the planned route in case of signal loss.

Piloting Precision on the RV Frequensea

About an hour before each launch, aboard the HMCS Margaret Brooke, Wilcox powered on the USV’s onboard computer, IMU, and Arrow Gold+ GNSS receiver. During this time, the Arrow Gold+ began its convergence with Galileo HAS, a process that typically takes 30-45 minutes while the service is in its initial Phase I.

Once the team was ready to launch the USV, Wilcox boarded a repurposed, multi-role rescue boat and took off into the icy waters.

The team lowered the USV from the HMCS Margaret Brooke by crane, released it into the water, and piloted it to the survey site.

At that point, Wilcox activated the sonar and began surveying.

Data from the Arrow Gold+, IMU, and sonar tools streamed to an onboard computer running QPS Qinsy. Next, this software integrated the data and transmitted them to Wilcox’s remote computer via Wi-Fi (i.e., MikroTik^® GrooveA 52).

An omni-directional antenna maintained the wireless link for up to 250 meters, allowing Wilcox to control the vessel remotely. If the USV went beyond that distance, the autopilot system would kick in, and the onboard computer would continue collecting data autonomously via backup settings.

Wilcox typically drove the USV back and forth for about four hours over each site, in successive survey lines. In this way, he collected synchronized data from the sonar, IMU, and GNSS receiver. As Wilcox drove the USV, he also monitored a live coverage map showing which areas had been surveyed.

At multiple times during each survey, Wilcox deployed a tool that helped further refine the sonar accuracy. The AML Oceanographic CTD contained salinity, temperature, and depth probes to analyze water columns, which are vertical profiles of water from the ocean surface to bottom. By profiling the water column properties at various locations and depths, Wilcox could later apply the data to the soundwave speed measurements and ultimately refine the accuracy of the sonar scans.

The surveys focused on important sites such as Admiralty Bay, a hotspot for climate change research; Livingston Island, known for its glacial geology; and the geothermally active Deception Island.

Surveying a Submerged Volcanic Caldera

Deception Island is home to one of just two active volcanoes in Antarctica. One of the most fascinating features Wilcox surveyed was the submerged, active volcanic caldera nestled within the horseshoe-shaped island.

The expedition aimed to determine whether the caldera — most recently mapped in 2012 — had changed over time due to volcanic activity. The updated bathymetry could provide valuable information for future hydrographic teams to improve their charts and understanding of the area.

“It’s not very often you get to go and survey something like that caldera,” Wilcox said. “That was a highlight for me.”

The resulting bathymetry from the survey provided a high-resolution picture of the cone inside the caldera, which will allow for comparison of changes over time.

The Results: Accurate Maps in Earth’s Most Remote Waters

The resulting surveys demonstrated that high-accuracy hydrographic mapping in remote areas is not only possible, but reliable, even in some of the most logistically challenging environments on Earth.

“We’re incredibly motivated by the initial results of the expedition,” Ocean Mapping Group Chair Ian Church said. “The teams’ collaborative efforts have resulted in a rich dataset that will provide back to the scientific and global communities for years to come.”

Long after the journey was over, Wilcox was still taking it all in.

“An expedition like this is one of those things that’s always going to be with you,” Wilcox said. “Twenty or 30 years from now, to be able to say, ‘Yeah, I was on the first one of those,’ and to see the impact of the research — that’s a rare honor.”

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