What would you like to see in Demetra ?

[Olivier GARDE]

What would be the improvements or functions that should be implemented in Demetra?

Graphic functions? automatisms? other things ?


Here you have the floor to tell us about your development wishes for Demetra

So don't hesitate to express yourself

[Michel Verlinden]

Hello,
An implementation for LHires III and different gratings.
A tool for absolut flux calibration with photometric slits and Alpy600 spectrograph.
Many thanks to Shelyak Instruments.

[Tony Rodda]

Hi,
Access to the automatic Calibration parameters file so that "other" spectroscope configurations of emission lines and dispersions can be set.
Many thanks to Shelyak. Demetra is a superb package.
Regards

[Jack Martin]

Olivier,

I use a Lhires 111 and all 6 gratings, would like to reduce spectra in Demetra.

Regards,

Jack

Essex UK

[Olivier GARDE]

Hi Jack,

At this time Demetra can reduce spectra from ALPY 600 and soon for eShel and LISA spectrographes.

But the futur goal is to reduce all spectra comme from all spectrographs from the Shelyak range including the LHIRES III.

[Olivier GARDE]

Hi Tony,

Yes in the futur, Demetra can do automatic calibration depending of the wavelength to observe.

And soon a version for the LISA and eShel spectrograph.

[Francois Cochard]

Hello all,
Some more details about the calibration in Demetra (to reply to your requests, Tony and Michel).
We're currently working on a significant improvement of the calibration tool. We consider that the automatic calibration is the normal way to use Demetra, but we know that sometime we need to "open the box" to make it (better) work.
Then, we're giving more control to the user for this calibration tool. Specially, we can edit the list of reference line, which is the core of the automatic algorithm.

See the example below:

20200102 Demetra calib.PNG (91.2 KiB) Viewed 25273 times

Is it what you are looking for, Tony? Anyway, you can always edit the text file with these calibration lines, but this is not convenient in real life.

Michel, regarding the Lhires III, the point is that we cannot use the same automatic calibration than Alpy, because we've no idea where we're in the spectrum. We've to define another way, requiring "human help". The good news is that we'll probably have the same need for UVEX (we're working on the instrument right now), then my feeling is that when we've the solution developped for UVEX, then we'll adapt it for the Lhires III.

Friendly,
François

[Francois Teyssier]

Bonsjour à l'équipe Shelyak et merci pour ces nouveaux outils.

Améliorations proposées:
- calcul vitesse radiale héliocentrique et possibilité de corriger le spectre de cette vitesse (BSS_HVEL)
- mémoriser dans le header: nom de l'étoile de référence, type spectral adopté pour l'étoile de référence, hauteur/air mass/heure d'acquisition de cette étoile.
Cela faciliterait le diagnostic lorsque des réponses atmo/intsrumentale plus ou moins erronées sont calculées.

François

[Jacques Michelet]

Hello,

As spectrometers need to be fine-tuned, a 'live-tuning' module may be quite helpful in Demetra.
For instance, for slit spectrometers, such a module would help to adjust precisely the output lens to make some lines of the calibration lamp as thin as possible. As the Demetra software already includes an acquisition and a calibration tools, I think that this would not be too complex to develop. To show what I am thinking of, attached is a screenshot of the outputs of a small piece of code I have written in that purpose to adjust my Lisa spectro.
Some other adjustments may be relevant, too, but I am not familiar with all Shelyak spectrometers.
Well, that's just an idea.

Best regards,

Jacques

[Francois Cochard]

Hello Jacques,

This is a good idea!
We started something long time ago, to help focusing the Alpy 600 ; this is still to be improved.
But the LISA focusing way is very different: we do it on the calibration light.
Well... I put this in the list, and we'll see what can be done.

Anyway, making tools to help the tunning of the instrument is exactily in the "Demetra spirit".

Friendly,

François