Fix Version/s: None
As stated in
DM-9862, meas_mosaic assumes the 0,0 for each CCD to be the lower left hand corner. LSST uses a different coordinate system so meas_mosaic rotates the wcs into the LSST frame when writing to disk. However the photometric correction is still in the HSC frame, so when applying the meas_mosaic correction we need to rotate the wcs back to the HSC frame. We can then create the photometric correction, rotate it into the LSST frame and apply it to the image. We then rotate the wcs back to the LSST frame.
Yeah, I probably didn't word it correctly. It is the same issue, but after testing I found a couple of things that weren't quite right. The wcs needed to be rotated back to the LSST system and you were rotating the image to apply the correction while I rotated the correction to apply the image.
Bob Armstrong, I've rebased this on LSST master as u/jbosch/
DM-10236. Your changes look fine to me, so if my rebase of your changes looks fine to you (there were some conflicts), please go ahead and merge.
Bob Armstrong, I never got to fully test it, and I may be misinterpreting the current issue, but this commit was intended to do what I believe you have described.