Masayuki Tanaka and Michitaro Koike (NAOJ) have put together a sky subtraction code (based on the HSC pipeline) that performs better for large objects than what we are currently using. Their approach creates sky frames from many observations and subtracts these from the data, with additional large-scale subtraction to deal with any small residuals. I need to:
1. Understand the details of the approach taken.
2. RFC this addition to the processing.
3. Implement the code on the LSST side.
Their code is on the koike/global-sky-subtraction branch of hscPipe.