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Data Export

CDAT can export the data view in two different ways:

  • Color images — the data view is written to an image with optional color scale and data information legends, used for web page images, printing, or presentation slides.
  • Scientific data — the variable values and metadata are written to a data file, used for import into data analysis or GIS software.

To export to a PNG image, zoom and pan to an area of interest and click the  Export button on the tool bar.  A window will appear with export options — click OK to use the defaults, and the data view with legends will be written to the same directory as the sample data file.  The PNG file should look similar to the following:

Example CDAT exported image showing sea surface temperature data in the Eastern Mediterranean Sea

You can also export the full SST variable data, for example to a raw binary file of 32-bit values:

  • Click the  Export button.
  • In the export window select the Binary raster format.
  • Click Options and in the options window select 32-bit float for the Data type.
  • Click OK and then OK again to export the data.  There should now be a 28 Mb .raw file in the same directory as the sample data (ie: 2048 pixels x 3600 lines x 4 bytes per value).  This data can be read directly using Matlab, Python, or C code for example (although using the NetCDF library on the original sample data file might be easier). 

Bonus exercises:

  • Try exporting to various different image formats: JPEG, GeoTIFF, PDF.
  • Some combinations of export formats and options can generate an 'unsupported option' error with this sample data file.  See if you can generate an error message.
  • Try writing a GIF image and limit the image to only 32 colors — view the resulting file.
  • Read the CoastWatch Utilities User's Guide Download CoastWatch Utilities User's Guide Section 3.10 and find out about export formats that may be useful to you.