Trouble Getting Image Annotated Properly

[sreilly]

I think I've discovered the reason for my issue with this image. As with all stacked images, at least in my case, you loose the coordinates in the FITS header when images are combined. To overcome this I thought I'd log into my Astrometry account and plate solve the finished image. There is an option to save the resulting fits.jpg image with the FITS header which is what I did and used in PI. While this seems to generate J2000 coordinates for the center of the image, what seems to be missing is the PA angle, in this case 252 degrees. What Astrometry reports seems to be LONPOLE and LATPOLE in which in this case the LONPOLE is given a value of 180 and 0.0 to the LATPOLE. I added the FITS keyword of ROT_PA and 252 as the value, saved and ran the script again with the same results. At this point I'm lost and have no idea what to do. The image as annotated with the script is here http://www.astral-imaging.com/M57_Annotated_Image.htm

Any thoughts would be greatly appreciated.

[pfile]

you could re-solve with ImageSolver (just search for the object near the center, M57) and then the solution generated by ImageSolver should be compatible with AnnotateImage...

rob

[Andres.Pozo]

AnnotateImage should be compatible with images solved by astrometry.net. Please check the option of FITS format for reading the image top-bottom or bottom-up.

I'm now at a beach resort without a PI installation so I won't be able to analyze this problem until the next week. 8) 8)

[sreilly]

Rob,

Maybe I'm misreading the process but the fits image generated by Astrometry is the color combined finished image (LRGB) and the coordinates are embedded. Using ImageSolver doesn't solve the image even after inputting the coordinates given by Astrometry or the ones I get from an individually solved image. I did solve one of the luminance images and the results were used without luck. The biggest difference I've seen between any I've tried is less than 1 arc minute.

Andres, I appreciate your taking time from your trip but enjoy the beach and it will be here after you return if you still wish to assist.

As I said in the original post, I think the rotation angle isn't being read as it seems the AnnotateImage seems to solve the image but not account for the PA angle of 252. I'm missing something basic I think.

Thanks Again,

[pfile]

i can't remember for sure but there were some WCS styles that AnnotateImage did not like in the past. i think SGP was writing something to the header that AnnotateImage did not like

if andres says AI is compatible with astrometry.net, then of course it is, assuming you are using the latest version of AnnotateImage.

if Imagesolver is somehow getting tripped up by the WCS header that astrometry.net has inserted, then you may have to delete it from the FITS header to get ImageSolver to solve the image from scratch, not sure. i guess i just meant to say using IS is a possible workaround for you.

so you are saying that AnnotateImage is annotating the image with the center coordinates set properly, but the annotation is rotated some number of degrees? i did not download your file.

rob

[georg.viehoever]

To me, this seems to be an upside down issue. Flip the image with FastRotation/vertical mirror, or set a different Coordinate Origin in FormatExplorer/FITS .
Georg

[sreilly]

Georg,

Perfect solution and one I couldn't see to save me! Flipped the image Vertical Mirror and all went well. Guess I can learn something new yet!

Thank you for the help and suggestions guys.

Steve

[sreilly]

So, one last question on using this tool. I know there are at least 13-15 faint dim galaxies in the top section, well now below, M57. What galaxies can be added that will likely pick these up. Currently the annotated image shows 8 PGC galaxies and 1 IC galaxy. I counted well over 20 galaxies but some extremely faint. Are there catalogs out there that PI can use to identify these?

Many thanks again,

Steve

time to cut the grass.......