Inverted SDSS DR12 images

[Richard Piccioni]

I have been downloading sets of FITS files from the SDSS DR12 Science Archive Server, specifically images of the same field and camcol taken through g, r, and i filters).  When I open the files in AJI, I find they are not oriented in the same way.  I do not see that behavior when I open the same files in SAOImageDS9.

I can reorient the non-conforming image using AJI View functions, but of course those adjustments do not persist, e.g., when I create an image stack.  I'd like my students to be able to work exclusively within AJI, so have tried hard to find/write a macro that changes the FITS itself, but without success.

Any advice would be greatly appreciated.

Here's a SAS search that yields FITS files showing this behavior:

https://dr12.sdss.org/fields/runCamcolField?run=125&camcol=1&field=12

Compare the g- and r-band FITS.

Thanks,
Richard

[karenacollins]

Hi Richard,

If you are running the latest daily build, you may need to disable the new option Image_Menus=>View=>"Auto WCS North up, East left". This problem occurs when image orientations on the sky are on the threshold of the flipping the orientation of North up, East left. The usual case is when North is pointing close to the direction of the X-axis instead of the Y-axis.

Karen

On 5/27/2020 12:46 PM, Richard Piccioni [via AstroImageJ] wrote:

I have been downloading sets of FITS files from the SDSS DR12 Science Archive Server, specifically images of the same field and camcol taken through g, r, and i filters).  When I open the files in AJI, I find they are not oriented in the same way.  I do not see that behavior when I open the same files in SAOImageDS9.

I can reorient the non-conforming image using AJI View functions, but of course those adjustments do not persist, e.g., when I create an image stack.  I'd like my students to be able to work exclusively within AJI, so have tried hard to find/write a macro that changes the FITS itself, but without success.

Any advice would be greatly appreciated.

Here's a SAS search that yields FITS files showing this behavior:

https://dr12.sdss.org/fields/runCamcolField?run=125&camcol=1&field=12

Compare the g- and r-band FITS.

Thanks,
Richard

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[Richard Piccioni]

Fantastic.  Changing that setting, followed by Image_Menus=>Process=> Align stack using image stabilizer, and that little asteroid is sticking out like a sore thumb!
Thanks so much,
Richard