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PixInSight Comet registration: error in DATE-OBS fits header - data from IRSA - ZTF

Pleiades Astrophoto PixInsight Processing Deep Sky Comet
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Stefano Zamblera avatar
Stefano Zamblera avatar
Dear friends I met a problem in PixInSight while attempting to process some data retrieved from here:
https://irsa.ipac.caltech.edu/applications/ztf/
about C/2020 F3 Neowise comet; for an overview of the resource while looking for Neowise set of available data please cfr:
https://www.astrobin.com/forum/c/group-forums/comets-imaging/c2020-f3-neowise-comet-raw-data-from-remote-hosting/

While attempting a comet registration of single subframes, star-registred single subframes, R G B masterframe (this latter in the creenshot) I always stop beacuse of the error "Acquisition time metadata not available (Observation:Time:Start property or DATE-OBS keyword): etc..."




I also tried to manual integrate this missing header part by adding date-obs

but it doesn't work.

May someone can help me please?
Thanks in advance and clear skies!!!
andrea tasselli avatar
andrea tasselli avatar
Where is the "DATE-OBS" field? if there isn't one you need to create one by editing the fits header.
Stefano Zamblera avatar
Stefano Zamblera avatar
andrea tasselli:
Where is the "DATE-OBS" field? if there isn't one you need to create one by editing the fits header.



Ciao Andrea grazie!
I've tried to add the field but it wasn't possible
andrea tasselli avatar
andrea tasselli avatar
Ciao Stefano,

Have you clicked the square button once the field has been added. Because it works for me:

Stefano Zamblera avatar
Stefano Zamblera avatar
andrea tasselli:
Ciao Stefano,

Have you clicked the square button once the field has been added. Because it works for me:




yes I did but let me try again and I’ll update about asap!!! Many thanks!!!
Stefano Zamblera avatar
Stefano Zamblera avatar
Sorry cannot give a screenshot.
After adding by process applying (square button and tracking arrow) and saving rgb subframes I still got the same error attempting comet registration:

* CometAlignment: Loading 3 file(s)
Loading image: w=3072 h=3080 n=1 Gray Float32
8 image properties
84 FITS keyword(s) extracted
*** Error: Acquisition time metadata not available (Observation:Time:Start property or DATE-OBS keyword): /Users/xiulong/Desktop/IRAS/C2020 F3 Neowise/C2020F3Neowise-08082020/04-INTEGRATION/B.xisf

Loading image: w=3072 h=3080 n=1 Gray Float32
8 image properties
84 FITS keyword(s) extracted
*** Error: Acquisition time metadata not available (Observation:Time:Start property or DATE-OBS keyword): /Users/xiulong/Desktop/IRAS/C2020 F3 Neowise/C2020F3Neowise-08082020/04-INTEGRATION/G_psf-snr.xisf

Loading image: w=3072 h=3080 n=1 Gray Float32
8 image properties
84 FITS keyword(s) extracted
*** Error: Acquisition time metadata not available (Observation:Time:Start property or DATE-OBS keyword): /Users/xiulong/Desktop/IRAS/C2020 F3 Neowise/C2020F3Neowise-08082020/04-INTEGRATION/R_psf-snr.xisf

Really don't understand why and how IRSA/ZTF fits data could be missing default fits header parts
andrea tasselli avatar
andrea tasselli avatar
Can you see the field DATE-OBS with a date once you open with the fits header viewer? Obviously you could process the whole lot in IRIS and be done with it.
Stefano Zamblera avatar
Stefano Zamblera avatar
No I cannot see the date-obs field comparing within the header. 
mmm
yes I’ll process elsewhere for comet registration. 
may I ask you please: do you have pixinsight in pc win, Linux or Mac?
mine is an m2 MacBook and I’m experiencing many crashes and bugs while processing, and maybe here I’m just in front of another one. 
I’ll try to play with pixinsight in linux and windows and see what happens
andrea tasselli avatar
andrea tasselli avatar
Then something is gone astray will adding the field and also make sure to save it on a different name and that the field value is actually a string so enclosing ' '. I'm using PI on a Win10 machine.