|-in|cat||focus.cat Input catalogue or single image|
|-dev||ASCII Output device or filename (see Graphical output)|
|-seq||start,step Linear focus ramp to be used if the focus keywords are missing|
|-range||3. Compute the focus range at the 3%-level|
xCFOCUS'(x=B or R) keyword giving the position of the spectrograph moving element (camera on the red channel, collimator on the blue one). If this keyword is not there, you can use the option
start,step to describe the focus ramp actually used.
The value used for the best-focus determination is <Sig> (RMS of SigX and SigY). It appears that the focus position is not very dependant on the quantity used (e.g. intensity).
ASCII', i.e. stdout:
# Focus Intens SigX SigY <Sig> d<Sig> 1 750.0 2.39e+10 1.242 1.574 2.005 0.041 2 800.0 2.53e+10 1.205 1.506 1.928 0.039 3 850.0 2.66e+10 1.174 1.459 1.872 0.038 ...
DISLINlibrary support, you have more choices (see Graphical output)
-quietstandard option for minimal output.
Test different zones in the arc frame (size and position, but beware of 0th and 2nd orders)
Fit multiple zones in the arc frame and derive a CCD-tilt
Check out why the Y-error bars are so different between the red and blue channels. The formal error estimates derived with
nllsqfit_bnd seem theoritically correct.