[Issues] Poor astrometry on SUBARU test field

[Tim Schrabback]

Dear John and Erik,

during the Leiden tutorial I randomly picked a multi-color SUBARU data set 
to work with. The results for the astrometry (Astrom) were poor, with
an RMS exceeding 1" for some chips/exposures. Looking at the frames they 
visually look fine. I think it would be very valuable to understand the 
cause for such poor results in order to further improve the Astro-WISE 
system.

If you want to check this yourself, this is how I ran the astrometry 
task:

pars=Pars(AstrometricParameters)
pars.AstrometricParameters.process_params.MAX_RMS=1.1
pars.AstrometricParameters.preastromconf.RMS_TOL=5.0
dpu.run('Astrometry', i='SUP', o='deep16_0', C=1,pars=pars.get())

We are currently performing extensive astrometry tests (also using 
different reference catalogs) using CFHTLS-Wide MEGACAM data outside of 
Astro-WISE. It would be good to get these data fully supported in 
Astro-WISE at some point, so we can do cross-checks.

Thanks and best regards,

Tim