SURF photometry and KAPPA

The photometry data reduction system produces one flux measurement per integration per bolometer. Further analysis simply involves finding a self-consistent mean of the merged data set (multiple measurements with a given bolometer can be concatenated together using scucat).

Figure: Photometry data of 3C279. This is the concatenated data from three separate observations.

The SURF package supplies two KAPPA scripts to aid with this step of the analysis:

• qdraw displays the data with a $\pm 5\sigma$ range, calculates and draws the 3-sigma lines and reports the mean and error in the mean of the supplied data set. This script uses the KAPPA routines stats, linplot and drawsig. Figure shows the data from the previous section as displayed with qdraw.

• If the data contains large spikes which are having a significant effect on the standard deviation calculation then sigclip can be used to mark bad all data that are outside a given n-sigma threshold. This script uses the KAPPA routines thresh and stats.

The KAPPA kstest routine can also be used to check the self-consistency of the photometry data by performing a Kolmogorov-Smirnov test on the data (e.g. [26]).