Since 2003, all underway multibeam and sub-bottom data from the Canadian Coast Guard Ship Amundsen has been posted online within approximately six months of the end of each cruise. A custom interface allowing the user to access 15' latitude by 30' longitude mapsheets was implemented in 2006, allowing the user to download the bathymetric and backscatter data at 10 metre resolution. While this interface matched the underlying data management scheme implemented at the University of New Brunswick, the zoom and pan capability was at a fixed scale with limited contextual data. In the past few years, with the introduction of web-based geographic information systems (GIS) (e.g. Google Maps, Yahoo Maps, Bing Maps), there have been thousands of maps published online. These online GIS programs are a suitable platform to display the seven years of Amundsen coverage within the context of the GIS-served satellite imagery and allow the user to freely browse all data in a familiar interface. The challenge, however, for serving up third party data through these map engines is to efficiently cope with the multiple zoom levels and changing resolutions. Custom tiling software was developed to take all the raw data from the seven years of Amundsen (and others') multibeam coverage and convert it into multiple scale resolution images suitable for interpretation by Google Maps. The images were stored in a pyramid structure utilizing Google's map projection and uniquely named to reflect their georeferencing and resolution. This image pyramid is then accessed by Google Maps according to the user's current zoom level to optimize visualization. This multi-resolution data is served up on demand from the University of New Brunswick for dynamic overlay on Google's satellite data. This web interface allows any interested parties to easily view multibeam and sub-bottom data from the Pacific Ocean through the Canadian Arctic Archipelago and into the Atlantic Ocean. The broad overview helps to understand regional trends and then focus on areas of interest at high resolutions to see particular features. The web interface also provides a link to the 15' by 30' mapsheet model with full source traceability.
Journal or Conference Title
Canadian Hydrographic Conference
Jun 21 - Jun 23, 2010
Quebec City, Quebec, Canada
Canadian Hydrographic Association
Muggah, James; Church, Ian; Beaudoin, Jonathan; and Clarke, J.E. Hughes, "Seamless Online Distribution of Amundsen Multibeam Data" (2010). Center for Coastal and Ocean Mapping. 783.