The following performance criteria have been set as targets for SuperCOSMOS.

- Measurement area 0.5m square.
- Absolute accuracy m, defined as the accuracy with respect to a
perfectly uniform rectilinear Cartesian coordinate system.
- Repeatability m, defined as the largest variation in the
absolute errors when measurements taken on different days are compared: it is
this performance criterion which is most important for obtaining accurate
astronomical results.
- Dynamic range , defined as the ratio of the highest
transmission value measurable on a UKST plate to the lowest transmission level
measurable at a signal/noise ratio of unity.
- Scattered light surface brightness times the maximum
measurable transmission value.
- Sampling interval m.
- Resolution (FWHM of point-spread function, including the effects of
finite pixel size) m.
- Time needed to digitise a UKST plate
**< 2**hours. - Time needed to analyse a UKST plate
**< 2**hours.

Mon Aug 5 15:56:21 BST 1996