There are two identificators per survey component to give extra room on defining strategies within parts of each survey (resp. A & B for High & Medium).

The CFHT New Observing Process provides access to the calibration plan which time is not accounted on the survey or other principal investigator time but taken from a specific time budget from CFHT. The calibration plan is made of several programs described in the following table.

Q95: two crowded fields in the summer and winter Milky Way are observed in each filter (u*, g', r', i', z') during each observing run to follow precisely the potential evolution of the image quality throughout time.

Q97: the QSO rule is to observe one Landoldt field that contain some Sloan standards at the beginning of each night in all 5 broadband filters (u*, g', r', i', z') only if the sky appears clear (i.e. no clouds visible and SkyProbe telling so). At the end of the night, depending on which filters were used during that night, another Landoldt field is captured in that subset of filters only. If the sky is non-photometric, no time is wasted capturing these frames of course. At the end of each observing run, Elixir benefits from a large sample of data from which it can extract a per run zero point for each filter.

Q96: Q97 is however a highly time consuming program and in 2004, we will start using secondary standards located in the CFHTLS deep fields since CFHT almost systematically point these fields every night.

Q98: for the exposures not acquired under photometric conditions, a special short exposure 1/10th of the original exposure time is acquired later on for photometry bootstrapping when the sky is clear.

Q99: the program that includes all the bias, dark and flat-field frames.