FITS header suggestions

Science Spectroscopy
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Hi!
A similar question was asked a while back in the old forums, but I’m hoping for some more specifics or, barring that, a wishlist. I have been making a NINA plugin (really, couple of them) to help me with details of the image acquisition piece with spectra. I won’t go into all the things I have been playing with, but it started with a tool to help with the process of keeping a spectrometer slit perpendicular to the horizon with a GEM mount. Its automatic if you have a rotator, or stops and prompts you with the correction angle if you have a manual rotator. It sets the angle to be correct based on the midpoint of the image acquisition, with extra time allowed for PHD2 to re-acquire (it has to be stopped for the rotation, but not re-calibrated). It can do other things… It uses the Mount’s RA, lat/non, etc. automatically. I also have been adding support to perhaps help with other aspects of image and data collection. NOT processing, calibration, etc…. Other very sophisticated tools do that.

I have the option of adding data to the FITS header fields (also file naming, directory naming, etc… all extensions to what NINA supports). I have looked at the standard NINA FITS header, and the headers Demetra creates. There are differences even in the basic data, like image start/stop, etc. I am interested in making this perhaps support the AAVSO submission process as well. I’m not sure this will be useful, since these are the unprocessed images, but… It may just be best to match, say, the Demetra or other expected input format.

Anyway, if there is a list of SPECIFIC header information and formats/tags, or even just a wishlist as I mentioned at the beginning, I’d appreciate knowing about it! Working with samples, etc. is also an option. The submission information mentions that the information must match, but I’d think it would take a bit more specifics on field details. I realize this may just be for manual comparison. Another option is simply logging the information.

Any inputs would be appreciated!

Thanks!

-Mike

1 Like
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Hi Mike,

AVSpec was designed to accept 1D FITS files which comply with the BeSS database’s format. The Technical Manual, which is linked from the AVSpec “Help” page, contains lists of required and recommended keywords:

I hope this helps!

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Exactly what I was looking for! I had seen the general reference to BeSS formats, but should have pulled this guide down. Thanks! -Mike

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If you need the SBIG FITS Header extensions used by a lot of amateur software, the document lives here: https://diffractionlimited.com/sbig-fits-extensions-sbigfitsext-1-0/
I’ve considered starting some discussion with the ASCOM Standards volunteers about trying to update this in order to “unify” the various FITS Header keys that people are adding to the various software applications.

1 Like
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Thanks Colin!

I’ll add that to my growing library of FITS info It has some information that clarifies some things, and definitely has items that seem important. It is interesting to see the differences between header fields in the different acquisition software… at the moment, I’ve only really looked at TheSkyX (which has a fairly extensive set - I see that it provides a number for airmass, for example), NINA and the ASI Studio software.

There is also the issue of the individual image metadata vs the items that change as images are combined, corrected, calibrated, etc. Fortunately, these are not apt to be a part of the Plugin.

Again, I appreciate the info! -Mike

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Hi Mike, Here’s a link to the FITS info used in MaxIm DL, which is fairly popular with AAVSO users due to its photometric capabilities.
FITS Header Definitions

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That’s a good list! Nice detailed descriptions…

I have not used MaximumDL so far… I know its popular with the serious folks, especially with observatory presence. Thanks again! -Mike

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Glad to be of service.
If you’d like to get a free trial, there’s a link on the product page:
https://diffractionlimited.com/maxim-dl/
Sorry for the shameless commercial.

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Not a problem! Thanks for the help!