Band set does not match spectral signature in SCP Plugin/QGIS

I’m trying to do a supervised classification to see land cover change using the Semi-Automatic Plugin in QGIS. After I create my ROIs and try to assess the spectral signature plot for the ROIs, I receive this error: “Spectral signature does not match band set. Calculate spectral signatures again.” This shows up as a "Critical’ error.

My methodology so far:

  • Downloaded my Sentinel-2 image and added only the bands with the same spatial resolution (e.g. B2, B3, B4, B8 for 10 m resolution) into the QGIS layers panel.
  • Preprocessed the image and created a band set with those 10 m resolution bands and ticked the box to ‘Create a virtual raster of band set.’
  • Selected a Training Input in SCP dock, created Macro Classes, and drew a polygon around my ROI.
  • Highlighted one of the MC IDs I just drew, added it to the spectral signature plot, and went to asses the spectral signatures and receive the critical error message: “Spectral signature does not match band set. Calculate spectral signature again.”

I am at a loss on how to fix this. Please HELP!

This forum is about SNAP, there might be other boards which are more suitable for your question.

Did you assign the wavelengths in the band set table?

Yes, I did assign the wavelengths in the band set.

Do you think I should set the center wavelengths to a standard value?

And what other board should I post my topic under if not here? Thanks!

QGIS SCP has a “Tracker” entry to “browse and report bugs”. If you are comfortable with Python and there are not relevant posts to the gitub issues for this project you may want to look at how the match is determined. Unclear documentation and error messages are bugs, so it is reasonable to ask for a way to see details of the mis-match the software detects.