  Commissioning of SCUBA-2 included a program of skydips and observations of
calibration sources intended to be folded into regular observing as standard
methods of source flux calibration and to monitor the atmospheric opacity and
stability. During commissioning, it was found that these methods could also be
utilised to characterise the fundamental instrument response to sky noise and
astronomical signals. Novel techniques for analysing on-sky performance and
atmospheric conditions are presented, along with results from the calibration
observations and skydips.
