Making data available in support of the blue economy, one step at a time

A comparison of the NONNA-100 to the NONNA-10

By Dana Gallant

Supervisor of the CHS Hydrographic Data Access Centre of Expertise

Part of the Great Lakes Bottom Mapping Working Group Winter 2021 Underwater Update newsletter. Subscribe here.

The Canadian Hydrographic Service (CHS) recognizes that knowledge of the seafloor is required for a  multitude of reasons; from scientific research to commercial applications and beyond, these reasons are why CHS is committed to collecting and sharing quality bathymetric data. 

On Sept. 24, 2020 CHS made a significant step forward in sharing a consolidation of its bathymetric data holdings for non navigational purposes, providing key information in support of the Blue Economy. Bathymetric data is  represented from all available methodologies and technologies—everything from lead line, single and multibeam sonars, to bathymetric LiDAR, with the most modern and technologically advanced taking precedence in areas of overlap. 

The CHS’ NONNA-10 data series represents a 10-fold improvement over its predecessor, the CHS NONNA-100 data series, which was released two years earlier. “NONNA” refers to NON-NAvigational, and the 10 or 100 references the approximate resolution of the data in meters.

In addition, CHS introduced the CHS NONNA Data Portal, to facilitate access to the CHS NONNA data. Users can view, query and download data directly from the portal. The CHS NONNA data are accessible free of charge via the data portal, both to view or download in various formats: 32-bit GeoTIFF, ASCII++, CSAR, and BAG. Since the September launch, the portal has enabled users to download over 84,000 CHS NONNA-10 products! 

Access to the CHS NONNA data supports a broad range of scientific activities including but not limited to: 

  • Geographical planning for activities such as identifying areas for resource exploration or  environmental protection, or supporting the protection of Species At Risk.
  • Numerical modelling to simulate habitat mapping or nutrient and sediment transport.
  • Informing policy and program development for a wide variety of marine-related activities.
  • Broader scientific research concerning ecology, climate change mitigation, and  geomorphology. 

Please visit the Government of Canada’s Open Data site for more information about the data and to access  the products. The CHS NONNA Data portal is currently a pilot project and as such, we encourage you to  provide feedback on your user experience and how you are using the data, such that we may meet your specific requirements even better going forward. 

The future of hydrography is digital, and the CHS NONNA data series is one small transformative step for  the Canadian Hydrographic Service in that regard. For any questions about the CHS NONNA data series, please see the CHS NONNA FAQ page, or contact

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