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Spectroscopy qns/comments

Posted: Fri Feb 16, 2018 7:05 am
by keving
Having become somewhat familiar with Prism and imaging, I had my first live session with Prism and my spectroscopy rig (Alpy 600) last night. (I have previously used this kit in a variety of settings).

First, I was keen to try the spectroscopy line focussing utility for setting up your instrument (I had done this 'by eye' before).
It worked well - FWHM for single line image is displayed in real time - but there apperead to be some issues in closing this utility down, and error messages were telling me that it was waiting for something that I had already shut down etc. (A kind of self-referential loop). I'll try and detail it another time, but just in case anyone else see this , its a heads up.

Later 'in the field' (aka my back yard) I tried using the slit-guiding option under the advanced tab in the guide panel of teh guide cam. If its doing what I think its doing (managing to guide on a split star image over a slit) then this is great! However, the accompanying utility (last option under main Spectroscopy menu) for grabbing the star position for this kind of guiding didnt appear to work. It generated a fixed option (x = 355) and a few graphs which seemed to pertain to a test/development session..??
I put the coords in by hand using the XY readout from the image.
Also, is the 'energy lobes' paramater (defaults to 20) an estimate of the percent of star light either side of the slit? How do we estimate this?

Finally in the slit-guiding, I couldnt seem to change the parameters on the fly. I put a new value in (for X-cord say) and pressed 'apply' but noting happned (the 'pending box stayed the same)

I think I got this to work during one run, but if these small quirks could be ironed out, the guiding becomes best in class I think...

BTW - is there a spell checker for thsi forum :)

Re: Spectroscopy qns/comments

Posted: Fri Feb 23, 2018 12:47 pm
by keving
I can answer one of my queries myself.
" I couldnt seem to change the parameters on the fly. I put a new value in (for X-cord say) and pressed 'apply' but noting happned (the 'pending box stayed the same)"

Another session showed that it did actually change the system behaviour. I guess a rationalisation of the 'new/old' vs 'pending/new' approch to guide parameter change might help, but at least I know what to expect now :)