Vector Data--NOAA has changed
much of this
NOAA chart on demand
Raster Data--NOAA is discontinuing raster charts
- NOAA soundings:
- http://maps.ngdc.noaa.gov/viewers/bathymetry/ .
- Turn on data in "NOS Hydrographic Surveys".
- Zoom in on map.
- Outline box
- Pick a survey by its ID,
- Get data in XYZ
the GZ file, and convert to a DBF file. May have to open in Excel, and save
as a CSV file, before the file will open in MICRODEM.
- BAG files will have the best data, for
- Can request conversion of BAG
file to XYZ.
- Can extract bands with GDAL, and
then open the band with the depths (the
second band has the uncertainty).
Have to edit out the missing data, and
multiply depths by -1.
- Grids will be huge, and may be
almost entirely missing data with small
"islands" of data. You can subset
and save just the areas with data.
Last revision 8/20/2020