The step that converts point soundings into a raster surface with one depth per cell. Methods range from shoalest-in-cell or mean to uncertainty-weighted algorithms. Cell size is tied to depth and sounding density, often 0.5 to 1 m in shallow water and coarser offshore, and charting surfaces may use variable resolution. The grid drives coverage checks and quality control and becomes the base for charts and gridded bathymetry products.
Gridding at 50 centimetres inside 20 metres, 1 metre out to 40, then 4 metres beyond.
Match cell size to sounding density: too fine and the surface fills with empty cells, too coarse and small features disappear.
Also heard as
- surfacing
- grid
- surface
Related terms
CUBE
Combined Uncertainty and Bathymetry Estimator: an algorithm that builds a depth surface by weighting soundings by uncertainty.
Bathy
Clipped form of bathymetry, used for depth data, depth surfaces or the depth-measuring part of a job.
Sounding selection
Choosing which surveyed depths appear on a chart so the shoalest water is always shown.
Holiday
A gap in survey coverage where no data was collected, which must be filled before the survey is complete.