README_UPDATES

List of fundamental updates since the FGCM paper.  This does not include
general code improvements and streamlining, which are a given.

- LUTs are now generated per CCD per atmosphere (rather than as a delta on top
  of the standard)
- LUTs now include a dI1 term for smoother interpolation in the I1 LUT
- g band SED approx formula updated
- aperture corrections included
- Y band SED approx formula updated
- Tau is fit in log-steps instead of linear steps
- Tau and PWV slopes are done in percentage terms.  Bounds allow significant
  variation through the night.
- PWV retrieval can be turned on.  (experimental)
- Tau nightly retrieval can be turned on.  (very experimental)
- Exposure gray can be smoothed through the night. (experimental)
- sub-ccd superstar flats can be turned on (if x/y provided).
- Multiple filters per band supported (e.g., HSC I->I2 change).
- Atmosphere tables can be precomputed and distributed with code.