High-resolution bathymetric surveys are revolutionising hydrographic surveying. ln addition to safety-of-navigation , there are a host of other uses for high-resolution bathymetry, including habitat mapping, hydrologic modelling, marine archaeology, and marine environmental protection. However, at present, there is no suitable method that can be used to produce multiple products that meet the needs of both navigation customers and other users . A research project conducted at the University of New Hampshire developed a model of the seafloor that is optimised for safety-of-navigation . This new technique bypasses the rather subjective, 'selected soundings' approach. Instead, a statistical model is created directly from the cleaned and processed data. The model - called a 'navigation surface' - consists of a high-resolution bathymetric grid with an uncertainty value assigned to each node on the grid. The model is then optimised to preserve the least depths over significant features . For each node an uncertainty value is computed which becomes an integral part of the model. The distribution of the points around the mean is combined with the predicted uncertainty of each measurement to form an overall uncertainty model. For low-density single-beam and lead-line surveys, the area between measurements is modelled based on a triangular irregular network (TIN). The uncertainty model then incorporates the distance from the measurement, as well as the uncertainty of the measurement itse lf.
Journal or Conference Title
International Hydrographic Review
3, No. 2 (New Series)
Lemmers, Amsterdam, The Netherlands
International Hydrographic Organization
Smith, Shep M. LT; Alexander, Lee; and Armstrong, Andy, "The Navigation Surface: A New Database Approach to Creating Multiple Products from High-Density Surveys" (2002). Center for Coastal and Ocean Mapping. 976.