Some JSA tiles considered by astoverlap to be identical
grahambell opened this issue · 1 comments
grahambell commented
If the regions output by TILEINFO for the tiles at the southern corners of facets 6 and 4 (the equatorial facets at RA 12 and 0) are given to ASTOVERLAP, it considers them to be identical:
$ tileinfo instrument="SCUBA-2(850)" itile=24576 region=24576.ast
$ tileinfo instrument="SCUBA-2(850)" itile=16384 region=16384.ast
$ astoverlap 24576.ast 16384.ast
The Regions are identical to within their uncertainties.
Maybe it's not looking at the different reference position for tile 6? Because this is one of the differences between the region files:
$ diff -U0 24576.ast 16384.ast
[...]
@@ -77 +77 @@
- SRef1 = 3.14159265358979 # Ref. pos. RA 12:00:00.0
+ SRef1 = 0 # Ref. pos. RA 0:00:00.0
[...]
The same is true for some other pairs such as 24579 and 16387.
grahambell commented
It looks like this might have been fixed by the abfacf0 commit.