OC3030 Oceanographic Computing and Data Display

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OC3030Oceanographic Computing andData Display
LCDR David O. Neander Winter 2001
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BATHYMETRIC DATA IN MATLAB
Multibeam data off Monterey acquired from NOAA
ships during the late 1980s
Data archived at NOAAs National Geophysical Data
Center (NGDC)
Acquired 5 CDs of data from NGDC (bathymetry and
shoreline)

• Data in binary format, required an extraction
  program to convert to xyz ascii (GEODAS)
• High resolution, huge datasets

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BATHYMETRIC DATA IN MATLAB

• Entire gridded dataset
• Over 4 million data points
• Could not incorporate additional data (xy
  shoreline)
• Required a projection to preserve aspect ratio

• Gridded subset
• Only 195,000 data points

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BATHYMETRIC DATA IN MATLAB

• Utilized MATLAB Mapping Toolbox to create
  mercator projection
• GRIDDATA performed a linear surface fit to
  the data (triangle-based linear interpolation)
• Plot using SURFM
• Ascii xy coastline extracted from GEODAS
  software

• A cubic surface fit to the data
  (triangle-based cubic interpolation)

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BATHYMETRIC DATA IN MATLAB
THREE DIMENSIONAL SHADED RELIEF

• SURFLM
• Elevation angle 75o
• Light source 45o

• 100-meter contour overlay

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BATHYMETRIC DATA IN MATLAB
SURFACE LIGHTED SHADED RELIEF

• SURFLSRM
• Combines surface coloring and surface light
  shading

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BATHYMETRIC DATA IN MATLAB

• Enhancement of bathymetric data can reveal
  some interesting features on the seafloor.