1. OC3030 Oceanographic Computing and Data Display
LCDR David O. Neander
Winter 2001

2. BATHYMETRIC DATA IN MATLAB
Multibeam data off Monterey acquired from NOAA ships during the late 1980’s
Data archived at NOAA’s National Geophysical Data Center (NGDC)
Acquired 5 CD’s 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

3. 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

4. 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)

5. BATHYMETRIC DATA IN MATLAB
THREE DIMENSIONAL SHADED RELIEF
SURFLM
Elevation angle 75o
Light source 45o
100-meter contour overlay

6. BATHYMETRIC DATA IN MATLAB
SURFACE LIGHTED SHADED RELIEF
SURFLSRM
Combines surface coloring and surface light shading

7. BATHYMETRIC DATA IN MATLAB
Enhancement of bathymetric data can reveal some interesting features on the seafloor….