CHS High Definition Bathymetry Trials

The Canadian Hydrographic Service (CHS) is involved in the development of the next standard to be used for bathymetric data named S-100. This new standard will permit the management of gridded bathymetric data in high definition. CHS wants to test and try technical solutions in collaboration with software manufacturers, mariners and other potential users of High Definition (HD) bathymetry. For this, CHS provides to interested persons datasets of HD bathymetry. The sector of Trois-Rivières harbour was selected for these initial trials.

• 16 cells of level 1
• 2 cells of level 2

These datasets are available under license and may be used for tests and trials only.

If you wish to request a copy of the test data, please download and save a copy of the Direct User Licence Agreement. You may complete it electronically or by hand. The portions of the licence to be filled in by the recipient are shown in blue text. Please return the completed DULA to CHS by fax at 613-996-9053 or by e-mailing the complete PDF file to CHSInfo@dfo-mpo.gc.ca.

Technical Details:

The data are coded into 32 bit Geotiff format. This encoding format was retained by CHS for now, but CHS plan to use the format JPEG2000 when the software libraries will be more accessible.

Suggested Open Source Library for Geotiff 32 bits is GDAL (Geospatial Data Abstraction Library) http://www.gdal.org

Level 1 : Cell covering an area of 0.02 x 0.02 decimal degrees with a grid resolution of 0.00002 decimal degrees (resolution of approximately 2 meters).

Level 2 : Cell covering 0.1 x 0.1 decimal degrees with a grid resolution of 0.0001 decimal degrees (resolution of approximately 8 meters).

Each TIFF file has a resolution of 1000 pixels by 1000 pixels

Each cell name begins with the S-W corner lat-long coordinate in decimal degrees followed by the level of resolution (example : 46307256_LOD1.tif).

Depths are in meters and referenced to chart datum

Depths above chart datum are coded as positive numbers while depths below chart datum are codes as negative numbers.

• Caris Easy View (free ware downloadable at http://www.caris.com)
• Global Mapper 10 (trial version downloadable at http://www.globalmapper.com)