Marine Bathymetry Data Collection

Bathymetry is the study and mapping of the sea floor. It involves obtaining measurements of the depth of the ocean and is the equivalent to mapping topography on land. Bathymetric data is collected in multiple ways:

1. Satellite data can be used to produce maps showing general features over a large area at low resolution. Satellite altimetry measures the height of the ocean surface. If there are hills/mountains on the sea floor, the gravitational pull around that area will be greater and hence the sea surface will bulge. This measurement can be used to show where the seafloor is higher, and this can be used to produce maps showing general features over a large area at low resolution.
2. Single beam echosounders produce a single line of depth points directly under the equipment. These measurements are usually made while a vessel is moving to identify general sea floor patterns and/or schools of fish.
3. Equipment that captures swathes of data by acquiring multiple depth points in each area, such as multibeam echosounders (or swath echosounders) and airborne laser measurements (LADS). These datasets are very high resolution, with data down to better than one metre accuracy.

This bathymetry dataset is a collection of singlebeam data sourced from seismic navigation lines, multibeam data, satellite and LADS data acquired by GA and by other government and non-government agencies.