QC: develop method to identify exposures where the tip-tilt system is railed

[awhoward]

See attached Quicklook images of spectra taken when the tip-tilt stage had a problem and a normal exposure.

The test could be to identify massive outlier in the time series of guiding corrections in the FITS table for the Guider.

[awhoward]

Let's think of other QC checks related to the Guider:

• guiding RMS jitter < requirement (50 mas)
• non-saturated pixels
• seeing measurement failed