QHY174m-GPS Non standard FITS keywords

[TimHaymes]

There are two FITS keywords ending with a hash "#" GPS_Tmp# and GPS_seq#
Both these header key words cause a problem with my exoplanet analysis which is performed by HOPS software. With GPS "On" these two #key words appear in the Header and cause the software to stop. By removing the hash with Asto Art the file is corrected and usable. I am reluctant to have to do this on 1000+ files. Can the # be removed in SharpCap please ?

Suggestions on how to correct the header in 1500 FITS files would also be appreciated.

Thank you very much

Tim

[admin]

Hi Tim,

sorry to hear that you have difficulty with the files not loading – I'd suggest that it might be a good idea to raise a bug against the HOPS software here - https://github.com/ExoWorldsSpies/hops/issues - to see if they can fix the problem to avoid you having to somehow reprocess the files.

Having reviewed the documentation, I can see that the # symbol is strictly speaking not allowed by the FITS specification, so I will change it for a future version of SharpCap.

Have you tried processing one of frames through PIPP - that can both read and write FITS files and can be set up to perform operations on them in bulk. I have no idea what it does with FITS headers – it might strip them all out or it might keep them all, but it may be worth trying to see if the processed file is then usable in HOPS.

Cheers, Robin

[TimHaymes]

Hi Robin,
Thanks for the tip. I did find this C stuff to manipulate FITS files: https://heasarc.gsfc.nasa.gov/fitsio/
BUT, since my programming skills are very rusty (!) im hoping i can find a ready made solution, like PIPP ( i hope)

I apologies for asking for you amend the FITS header for GPS. When I did these measurements the first time, i used the PC clock (not GPS) and there was no problem with the FITS files, expect the time was a bit out! GPS is preferable

Thank you very much

Cheers Tim

[procyon12]

Hi Tim,

PixInsight can do the job: FITSheader-tool: remove the related keywords# > create Process Icon, then batch processing using Image Container.

Christian

Edit: Sorry, just tested: it doesn't work. It removes the two bad keywords, but makes the keywords of all files the same
Christian

[TimHaymes]

Hi Christian,
Thanks for trying that. I looked at PIPP user manual, but is not useful in this regard. Shame Pixinsight gives an unexpected result. It would have been handy.

The next step could be to contact HOPS development group indicated by Robin, but im still hoping there is another way to rescue 2.5 hrs of data on Qatar-1b.

Tim

[admin]

Are all the files in one folder? Send me one and I will look to see if anything can be done.

Robin

[TimHaymes]

Sorry for the delay in answering. I contacted Fabio at AstroArt on the off chance that AA could do it.
AA will not change Key words (only the value), but Fabio found a way with Find-and-Replace (v1.8.1) a free tool that can be downloaded. This changed the keyword GPS_Tmp# in the FITS (I put in GPS_TEMP). I ran the batch twice for both # keywords. I was then able to use all 1400 files.

Cheers - Tim

[admin]

Hi Tim,

Glad to hear that you got that sorted – just to confirm that in SharpCap 3.3 the '#' character is removed from the header names to avoid this problem in future.

Cheers, Robin