Hello
I have been using ImageSolver and AnnotateImage successfully for some time now. However, I have recently run into an issue with ImageSolver and WCSHeader reporting different Rotation and Flip Status, with a flow-on effect on AnnotateImage.
I do not know if this is related in any way to my separately reported issue with PhotometricColorCalibration (related to plate solving).
I conducted the following tests on a single image field downloaded from the Sloan Digital Sky Survey (SDSS) DR 12 Science Archive Server (SAS). Screenshots are provided at the following link:
https://drive.google.com/drive/folders/1VlAN6GATZYOcIJyMomiSTqnLjc01AFMm?usp=sharingTest results are as follows:
• The first two screen shots display the outputs from FITS Header, WCSHeader and AnnotateImage.
o WCSHeader reports a Position Angle = 269 degrees 05.1 minutes (mirrored)
• The second two screenshots display the Process Control in addition to the other processes/scripts AFTER executing ImageSolver.
o WCSHeader now reports a Position Angle = 089 degrees 05.3 minutes (NOT mirrored)
o The ImageSolver output in the Process Console reports a Rotation = 90.899 degrees (flipped)
o The FITSHeader shows that the values for CD1_2 and CD2_2 are negative to that prior to running ImageSolver.
o More obviously, the RA coordinates in the annotated image progress in the opposite direction to that before executing ImageSolver.
Given there is more than one way to record rotation angle in a FITS header, is it possible there is an issue with the values ImageSolver is recording for CD1_2 and CD2_2, the WCSHeader calculations, the initial platesolve records in the SDSS metadata, or all of the above?
For your advice/consideration
Regards
Dean
