The WFCAM Science Archive standard star calibration data is kept in databases named WFCAMCAL‹semester›. semester denotes the last semester included in the database from 05A onwards, eg. WFCAMCAL08B includes data from 05A up to 08B. This is the set of data taken to calibrate WFCAM. There are 58 pointings that cover 49 faint stars in the UKIRT Faint Star catalogue. Some stars are covered in more than one pointing so that the same star is observed on multiple detectors. The fields are observed when they are closest to the zenith and are observed in all broad-band filters: Z, Y, J, H, K. Occasionally the current complement of narrow band filters are also observed. Each field is observed multiple times and the time between repeat observations in the same filter is much greater (typically one day) than the time to cycle through all filters (5-10 minutes) so the data are processed to give colours at each epoch through the SynopticSource table: a correlated multi-epoch data set.
The products include deep images and catalogues and multi-epoch variability selection. The total area covered is ∼10 square degrees, at a range of RA and dec and stellar density.