Exercise: Create a Spectral Library

Data

Use the image apex_2015_180_smooth.

Exercise

For each land cover class (see previous exercise), try to find several good spectra to add to the Spectral Library. Don’t forget to add a metadata class for each spectrum. You won’t remember afterwards!

  • Turn off the OpenStreetMap layer in order not to get errors.
  • Zoom to one of the images.
  • Open the tool to build your own Spectral Library select.
  • Click on some random pixels and see the features appear on the plotting window. Add them to your spectral library by clicking on the Add button add.
  • Toggle the Auto button auto to automatically add profile to your spectral library.
  • To remove a profile, select it in the attribute table and use the Delete button del.
  • You can now edit the profile metadata, add or remove non-compulsory fields and zoom/pan to selection on the image.
  • Save the Spectral Library to the ENVI Spectral Library format (.sli) save.

Result

The resulting Spectral Library can look like this:

../../_images/ex2_library_from_pixels.PNG

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