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INDI Library v2.0.6 is Released (02 Feb 2024)

Bi-monthly release with minor bug fixes and improvements

Incorrect FITS headers

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Incorrect FITS headers was created by PDB

Hello,

Found 2 issues with the FITS headers in current Libindi/Ekos

1. Missing FILTER keyword in header
When Filter is selected to be part of the capture filename, then the FILTER keyword not written in the FITS header. When filtername is selected to be part of the filename, the FILTER keyword appears in the header. Think it should always be there.

2. Incorrect DATE-OBS format
The time in DATE-OBS keyword is formatted with a Z at the end

strftime(iso8601, sizeof(iso8601), "%Y-%m-%dT%H:%M:%S", tp);

// Add millisecond and Z for Zulu/UTC time.
snprintf(ts, 32, "%s.%03dZ", iso8601, static_cast<int>(startExposureTime.tv_usec / 1000.0));

return (ts); strftime(iso8601, sizeof(iso8601), "%Y-%m-%dT%H:%M:%S", tp);

// Add millisecond and Z for Zulu/UTC time.
snprintf(ts, 32, "%s.%03dZ", iso8601, static_cast<int>(startExposureTime.tv_usec / 1000.0));

return (ts);

This is not correct according to the FITS standard:

KEYWORD: DATE-OBS
REFERENCE: FITS Standard
STATUS: reserved
HDU: any
VALUE: string
COMMENT: date of the observation
DEFINITION: The date of the observation, in the format specified in the
FITS Standard. The old date format was 'yy/mm/dd' and may be used only
for dates from 1900 through 1999. The new Y2K compliant date format is
'yyyy-mm-dd' or 'yyyy-mm-ddTHH:MM:SS[.sss]'.

When doing data reduction on a series of images, data reduction in AstroImageJ does not read these dates. (If I update all headers and remove the Z, data reductionb will work)

Think this should be brought into accordance with standard FITS.

Thanks,

Paul
The following user(s) said Thank You: Alfred, Greg
5 years 5 months ago #30772

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Replied by Jasem Mutlaq on topic Incorrect FITS headers

1. Cannot reproduce it. The filter name settings in Ekos is completely unrelated to the FITS header generation. Any way to reproduce this?
2. Fixed in GIT .
5 years 5 months ago #30782

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Replied by PDB on topic Incorrect FITS headers

Thanks for the quick fix.
Did some more testing but can't replicate it anymore. (At least not with the simulators). I will need to do some more testing with the real equipment (SX-Wheel) and on my non-test equipment. Will need some time for that.
Unfortunatelly deleted a lot a files yesterday to make space on the systems, so can get these back either.

It is not urgent, I have a python program that can insert filters if needed.

Regards,

Paul
5 years 5 months ago #30788

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Replied by Jasem Mutlaq on topic Incorrect FITS headers

Double check in your CCD --> Options. Filter under "Snoop Devices" is set to the filter wheel full name.

5 years 5 months ago #30795
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Replied by PDB on topic Incorrect FITS headers

Will do. Could very well the case something was set incorrect there. At least found 1 file back which misses the FILTER keyword. (it happened, now trying to reprodiuce)


Leave it for now. Will come back when I find why.

Regards,

Paul
5 years 5 months ago #30796
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Replied by Christopher on topic Incorrect FITS headers


@Jasem: I'm observing the same problem (Filter not written into FITS header) and indeed in my CCD options Filter Snoop Devices is not set (did work before recent updates though). Full name should be "ASI EFW" as shown in filterwheel's General Info but the setting does not get applied in CCD's options tab. By clicking set the value "ASI EFW" does not get written into the settings. Any ideas?

Thanks!
2 years 4 months ago #77160

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Replied by Jasem Mutlaq on topic Incorrect FITS headers

I have ASI EFW here... so how can I replicate this issue exactly? Would be appreciated.
2 years 4 months ago #77161

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Replied by Christopher on topic Incorrect FITS headers

If possible you can connect to my setup via TeamViewer.

Otherwise: I have ASI1600MM Pro and ASI EFW connected. Setting "ASI EFW" under CCD's snoop devices has no effect.
My software should be up to date, though I had some self compiled INDI binaries running before recent updates due to RST-135 driver fixing.
2 years 4 months ago #77162

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Replied by Christopher on topic Incorrect FITS headers

Jasem, I'm using indi_asi_ccd. In the attached screenshot you can see that after clicking "Set" nothing get's written into the value dialog box.
2 years 4 months ago #77243
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Replied by Jasem Mutlaq on topic Incorrect FITS headers

Is ASI EFW selected as the filter wheel in capture module?
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2 years 4 months ago #77244

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Replied by Christopher on topic Incorrect FITS headers

 Yes, it was. But I actively set it to "--" and back to "ASI EFW" now it's displayed as snoop device and FILTER is being written into the FITS header. Great, thank you, Jasem!
2 years 4 months ago #77245

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Replied by Jasem Mutlaq on topic Incorrect FITS headers

Btw, which KStars version are you running? This was recently fix in GIT (so you don't have to actively select it).
2 years 4 months ago #77246

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