Monitor long-term instrumental and site trends for the Survey. Assign quality indicator to every scan and feed back to survey scheduler.
Tape is readable and contents agree with log file.
Difference between nightly Instrumental Calibration images and canonicals within threshold. Photometric quality of night passes minimum acceptable criteria. Nominal sensitivity of detectors as gauged from calibration scan repeats is within Level 1 specifications, in context of seeing and BG conditions. Nightly averaged scan step size and array rotations within tolerances for optimal dithering pattern. Optical system does not exhibit problems related to focus, distortion , etc.