User's Guide – 2.5 Quality assessment

Although source-detection parameters are chosen opting for a good balance between detection completeness and spurious source content and stacked source detection likely reduces the spurious content compared to individual observations, false detections remain: for example along instrumental features, stray light, or residuals in the PSF fit to bright sources. The catalogues thus include information on the detection quality in the form of flags that indicate whether a source is probably spurious or located in a problematic region where its parameters are determined less precisely than in clean regions.

Quality assessment is done in two steps: automated by the SSC-internal SAS task dpssflag and manually by visual inspection of each stack.