Image solver and mosaic

[jjhublin]

Hi,
In order to built a mosaic of NGC 4216 region, I collected a large amount of data for two overlapping panels and processed them in WBPP. The image solving of one of the panels is not a problem but it is impossible to achieve for the second, taken in similar conditions. It doesn't work either with the linear versions of the masterLights (L, R, G, B), or with the stretched versions, autocropped or not. I tried with GAIA DR3 (XPSD) catalog. I also failed. Here is the link to the cropped version of the masterLight L for the problematic panel:

JJ Hublin sent you 1 item

masterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-L_mono_autocrop.xisf

www.dropbox.com

Any help would be greatly appreciated.

 

[cloudbait]

Hi,
In order to built a mosaic of NGC 4216 region, I collected a large amount of data for two overlapping panels and processed them in WBPP. The image solving of one of the panels is not a problem but it is impossible to achieve for the second, taken in similar conditions. It doesn't work either with the linear versions of the masterLights (L, R, G, B), or with the stretched versions, autocropped or not. I tried with GAIA DR3 (XPSD) catalog. I also failed. Here is the link to the cropped version of the masterLight L for the problematic panel:

JJ Hublin sent you 1 item

masterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-L_mono_autocrop.xisf

www.dropbox.com

Any help would be greatly appreciated.

That image is already solved!

 

[jjhublin]

That image is already solved!

Thanks for the feedback. What I can't seem to do is produce a _WCS.xisf files using the script "Image Solver". This is a requirement for my mosaic workflow. It worked with one panel, but not with this one.

** Warning: Process finished with errors:
masterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-L_mono_autocrop.xisf: The image could not be plate solved

 

[nico1038]

Thanks for the feedback. What I can't seem to do is produce a _WCS.xisf files using the script "Image Solver". This is a requirement for my mosaic workflow. It worked with one panel, but not with this one.

** Warning: Process finished with errors:
masterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-L_mono_autocrop.xisf: The image could not be plate solved

What version of Pixinsight are you using?
I believe since version 1.8.9-2 Pix stores its astrometric solution in XISF properties and no longer generates WCS fits keyword.

What are you using these files for? Can't you use the MosaicByCoordinates script once your panels are solved?

 

[cloudbait]

Thanks for the feedback. What I can't seem to do is produce a _WCS.xisf files using the script "Image Solver". This is a requirement for my mosaic workflow. It worked with one panel, but not with this one.

** Warning: Process finished with errors:
masterLight_BIN-1_6248x4176_EXPOSURE-180.00s_FILTER-L_mono_autocrop.xisf: The image could not be plate solved

What's your mosaic workflow? I've never needed such a file.

 

[fredvanner]

What I can't seem to do is produce a _WCS.xisf files using the script "Image Solver".

I don't remember ever producing a "_WCS.xisf" file - i.e. an XISF file with a "_WCS" suffix. Was that an output option in some earlier version of ImageSolver?

 

[jjhublin]

I'm using Pixinsight version 1.8.9-2 and it does create WCS files when using the "Image Solver" script. For some reason, it works on one of my panels but not on the other. It remains a bit of a mystery. However, the MosaicByCoordinates script manages to position the panels in their linear versions. I now hope to be able to continue with PhotometricMosaic. Thanks for the unblocking.

 

[cloudbait]

I don't remember ever producing a "_WCS.xisf" file - i.e. an XISF file with a "_WCS" suffix. Was that an output option in some earlier version of ImageSolver?

I seem to recall such files being mentioned, although I don't remember ever creating one myself. Or needing one for mosaics.

 

[cloudbait]

I'm using Pixinsight version 1.8.9-2 and it does create WCS files when using the "Image Solver" script. For some reason, it works on one of my panels but not on the other. It remains a bit of a mystery. However, the MosaicByCoordinates script manages to position the panels in their linear versions. I now hope to be able to continue with PhotometricMosaic. Thanks for the unblocking.

If you're trying to use ImageSolver on anything other than the active view it can behave... oddly. (In which case it doesn't generate any files.)

 

[fredvanner]

OK. I now understand. I never use the "File list" option in ImageSolver. When using this option, an extension is added to the solved files, which are written to disk in the source file folder. The current extension is "_ast"; I guess it used to be _WCS when the solution was written using FITS WCS format in the FITS header. Since the current ImageSolver only writes the XISF astrometric solution, the "_ast" extension makes sense. This solution should work fine for PixInsight tools, but will be no use for any non-PI tools looking for a FITS WCS solution.