This primitive calculates image quality statistics based on an input catalogue. This catalogue is typically the output from either Starlink::Extractor or Starlink::Autoastrom, so that object morphology information is available for calculations.

This primitive calculates the mean axial ratio of bright sources, the sky brightness, the limiting magnitude, a transparency estimate and the instrumental zero point.

• Files results with the Calibration system. FWHM is obtained with the fwhm() method, axial ratio is obtained with the axial_ratio() method, sky brightness is obtained with the sky_brightness() method, limiting magnitude is obtained with the limiting_mag() method, and the zero point is obtained with the zeropoint() method.

None.

Astro::Catalog.