Can't use comet alignement, DATE-OBS keyword problem

[Thierry Van Driessche]

I am using the latest version of PI together with the latest updates. Bias and darks have been integrated, masterbias and masterdark saved. Image calibration has been done on the lights using the masterbias and masterdark. When trying to launch the cometalignement, I get the error message "DATE-OBS keyword not found or invalid" on every xxxxxxx_c.xisf file.
Staralignement works fine.

Any idea what causes the problem and how to avoid it?

Thanks and best regards,
Thierry

[oldwexi]

Hi Thierry!
CometAlignment needs the DATE-OBS keyword with the correct capture data in it.
Because CometAlignment is aligning the star registered images according to the capture time!

Find attached a screenshot how to look at the fits header and how the
DATE-OBS Keyword should look like.

You should also load a raw image to see if the DATE-OBS keyword is there or already missing
in the raw data. As the error message says no DATE-OBS information no way to align the comet according to his movement!



In addition the workflow is:
first do StarAlignment
than use the registered output in your case xxxxx_c_r.xisf
as input for the CometAlignment.

Gerald

[Thierry Van Driessche]

Hi Gerald,

Thank you for the prompt reply. I guess I found the answer thanks to yours. In fact, for once, I have been taking my pictures in jpg format and not in raw. And indeed, my jpg's don't have a DATE-OBS keyword while earlier raw's that I have been taken does have the keyword.
Thank you for the additional info regarding the workflow. I missed that one 

Best regards, Thierry