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I would more than happy to help. I also now have experience of doing very low resolution spectroscopy at a remote hosted site. I am develop a new instrument based on an alpy which will use similar techniques to the high resolution work.
Regards Andrew
Achromatic, tracking, field rotation. Eyepieces bring a new set kidney bean, astigmatism, distortion….
Regards Andrew
https://www.atik-cameras.com/core-software-downloads/
Regards Andrew
This looks like an instrument / programming task in the context of astronomy. If your interested go for it.
Regards Andrew
Very, very, tempting and would love to do it. However, at 69 I should perhaps leave it to a younger candidate in need of the experience.
Regards Andrew
Yes but given the low read noise you can stack multiple short exposures to get the same S/N ratio. This is the normal strategy with CMOS cameras.
Regards Andrew
You might find what you want here https://www.edmundoptics.co.uk/f/first-surface-mirrors/12017/
Regards Andrew
You should convert ADU to e using the (inverse) gain in e/ADU for a real measure of S/N. This is probably what your software is not taking into account. The gain does not change the number of photons captured (assuming it’s not saturated ) .
You can quite easily measure the gain in the right units see here for example http://www.astrosurf.com/buil/isis/noise/result.htm
Regards Andrew
I am not sure I agree with this. Yes increasing the gain reduces the well depth but thus can be compensated for by take more shorter exposures and or defocusing.
Increasing the gain reduces both the read noise and the quantisation noise.
There is a balance to be had trading off these factors. I use a gain of 200 (ASI gain) for my spectroscopy.
Regards Andrew
Have a look at this http://www.astrosurf.com/buil/atik_vs_zwo/
Regards Andrew
I have converted the STScI Calspec spectra from there original fit table format to a “flat” fits format that can be read by BassProject and ISIS. One or two obscure spectra did not convert. I have included some notes (with spelling mistakes) and a Excel catalogue culled from the two on the Calspec site.
I have sent a copy of the 20.5 Mb zip file to Andy to consider making it available from the BAA web site.
I eyeballed all the spectra and checked a small random sample against the originals using Tim Lester’s PlotSpectra which can display the original along side the converted ones.
Here is a comparison of the original and converted spectra of Alpha Lyr. Black is converted blue original.
I anyone needs it now I am happy to email it to you.
Regards Andrew
What I will do is do two zip files one with everything (may not do the NGC entries) and one with just A & B stars. It will take a few days to do the all!
Regards Andrew
PS Just did them all in the end as it was simpler.
Hi Andy – I think less than 60 files (20 or so if restricted to A or B stars). I am putting them in text files in the ISIS .dat format ( wavelength flux) so far the are all under 9,800 KB the names are as in the CALSPEC catalogue https://www.stsci.edu/hst/instrumentation/reference-data-for-calibration-and-tools/astronomical-catalogs/calspec .
I could put them in fits format but I am not sure (need to test) if that would require me to resample them to a fixed wavelength interval and I would rather not change the data.
Regards Andrew
Two things one the equation if time so that meridian crossing of the sun is not exactly at noon or midnight UTC and sea tides lag the moon position. Not sure what impact they have though.
Regards Andrew
