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Band selection

selected_extensions decides which files of a FITS set are loaded, on every backend. Names are matched against the band in each filename (VIS, NIR-H, …), so selecting three bands from a four-file Euclid set loads exactly those three, in catalogue order, and channel_weights needs one entry per selected band. Use "PRIMARY" to switch band selection off and load every file in the set.

A selection that names no known band

A selection naming no band Cutana recognises narrows nothing, so every file in each set loads. On non-Euclid data that is the normal case: the UI labels a file the recogniser cannot classify UNKNOWN, and there is no band behind that label to select on.

This is logged once per run, because the other way to reach it is a typo: "NIRH" narrows nothing just as quietly.

A selection that matches no file

Warning

A selection that names real bands but matches no file in a set asks for data that set does not contain.

  • create_cutouts_direct() raises ValueError.
  • The orchestrator and streaming backends skip that set and log Skipping FITS set, so one tile that lacks the selected bands does not cost the tiles around it. Search the log for it before reading a short run as a complete one.
  • If the selection matches no set, every backend fails: that is a misspelled or inapplicable selected_extensions, not a gap in the data, and the error names both the bands you asked for and the bands that are there.