Schematron using XPath 2.0
A top-left corner must be provided
A top-right corner must be provided
A bottom-left corner must be provided
A bottom-right corner must be provided
The "Calibration" observation type may only be used with Products with a purpose of "Calibration"
The attribute @unit must be equal to one of the following values 'arcmin', 'arcsec', 'deg', 'hr', 'mrad', 'rad'.
The attribute @unit must be equal to one of the following values 'arcmin', 'arcsec', 'deg', 'hr', 'mrad', 'rad'.
The attribute survey:corner_identification must be equal to one of the following values 'Bottom Left', 'Bottom Right', 'Top Left', 'Top Right'.
The attribute survey:reference_object_type must be equal to one of the following values 'Asteroid', 'Comet', 'Galaxy', 'Star'.
The attribute @unit must be equal to one of the following values 'arcmin', 'arcsec', 'deg', 'hr', 'mrad', 'rad'.
The attribute survey:calibration_type must be equal to one of the following values 'Bias', 'Dark', 'Flat Field', 'Fringe Correction'.
The attribute survey:observation_purpose must be equal to one of the following values 'Calibration', 'Followup', 'Survey'.
The attribute survey:observation_technique must be equal to one of the following values 'Non-Sidereal Drift Scan', 'Non-Sidereal Stare', 'Sidereal Drift Scan', 'Sidereal Stare', 'Track-And-Stack'.