Transcript MR3522 Remote Sensing of the Atmosphere and Ocean

OC3030
Oceanographic
Computing
and
Data Display
LCDR David O. Neander
Winter 2001
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
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
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)
BATHYMETRIC DATA IN MATLAB
THREE DIMENSIONAL SHADED RELIEF
• SURFLM
• Elevation angle 75o
• Light source 45o
• 100-meter contour overlay
BATHYMETRIC DATA IN MATLAB
SURFACE LIGHTED SHADED RELIEF
• SURFLSRM
• Combines surface coloring
and surface light shading
BATHYMETRIC DATA IN MATLAB
Enhancement of bathymetric data can reveal some
interesting features on the seafloor….