First all-Canadian Antarctic expedition creates underwater maps using GNSS technology

May 8, 2025 - By Jesse Khalil

By adding high-accuracy locations with an average accuracy of 10 cm to 20 cm horizontal and vertical, the team was able to accurately georeference and further refine the detail of the bathymetry for their map inside the underwater Deception Island caldera. (Photo: Eos Positioning Systems)

Canadian scientists recently led their first Antarctic research expedition, using Montreal-made Arrow Gold+ GNSS technology for precise location data in remote and challenging conditions. The mission, which departed in early March 2025 aboard HMCS Margaret Brooke, included experts from multiple Canadian universities and government agencies. Researchers conducted water, sediment, air, and sea-ice sampling to study climate change, glacial retreat and pollution such as mercury and microplastics.

The month-long journey around the South Shetland Islands and the northern Antarctic Peninsula yielded surveys of coastal and oceanic sites. The crew relied on a small, unmanned surface vessel (USV) carrying various equipment for bathymetric surveys including an onboard computer, IMU and multibeam sonar.

In order to find the USV’s precise position in an environment with no land-based RTK infrastructure, the team relied on the Arrow Gold+ GNSS receiver, designed and manufactured by Canadian-based Eos Positioning Systems. The Arrow Gold+ utilized Galileo High Accuracy Service (GalHAS), a free satellite-based PPP correction available worldwide from the European Union’s Galileo Programme.

“There aren’t any RTK networks in Antarctica,” said Kevin Wilcox, Ocean Mapping Group research scientist, who piloted the USV. “That sent us looking for the Arrow Gold+ and GalHAS corrections. When we found these, we realized we had a possible solution.”

While using GalHAS corrections, the Arrow Gold+ provided estimated accuracies of about 10 cm horizontal and 15 vertical to 20 vertical.

“The vertical accuracy was especially important for our bathymetric work,” Wilcox said. “Any vertical error would directly add error to our depth.”

Sites surveyed include Admiralty Bay, Livingston Island and Deception Island, which includes an active, flooded volcano caldera. The resulting, high-accuracy maps will support further scientific and oceanographic research, environmental monitoring, and improvements to marine charts.