- changed status to resolved
Coordinate off-sets
The catalog coordinates are always significantly off-centered compared to what would be expected from deep HST imaging.
One possible source of error is the datacubes astronometry. However, I believe it is more likely that something in the cataloging tool is not correct. Especially the calculation of coordinates is performed on sub-cubes and so I have to translate coordinate systems back and forth at this step... There a lot of stuff could go wrong...
Attached is a screenshot of the problem. Mostly the sources are off-set to the west - but sometimes also a little bit to the south ... In our case the x-axis runs directly from west to east and the y-axis runs from south to north.
Comments (3)
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reporter -
reporter - changed status to open
ok - I'm confsused - so 0 in
wcs_obj.wcs_pix2world(x_coords,y_coords,0)
seems to be correct - because the coordinates in the lsd_cat are 0-indexed...We were affected by this since an older version of lsd_cat_lib.py was running on our MUSE machine. So it was already fixed in the code - 1ef253c9d28c then broke it again ... TGIF
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reporter - changed status to resolved
wcs_obj.wcs_pix2world(x_coords,y_coords,0) - since x_coords and y_coords are 0-indexed in the output catalog - this re-fixes issue
#5→ <<cset b83440b3ae7b>>
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lsd_cat_lib.py - pix_to_radec now calling astropy.wcs.WCS.wcs_pix2world with an 1 as origin - hopefully fixes issue
#5→ <<cset 1ef253c9d28c>>