I'm not sure if this is related, but I noticed that RA was coming up as a
negative number as well (the correct number as in this case, just not on
the interval 0-24 hr) when I was modifying the scuba2 data simulator code.
To summarize how I got it to happen: I have a centre RA, Dec for the
simulated telescope pointing, and a series of tangent plane offsets from
that pointing centre. If you recall I was writing code to take those
offsets and do the tanplane -> spherical coordinate transformation. I
first created a frameset (fs) to do the transformation by specifying WCS
fits channels and using astRead. I used astTran2 to get the spherical
coordinates from the offsets:
astTran2( fs, 1, &xi, &eta, 1, &this_ra, &this_dec );
The spherical coordinates of the tangent point used to make fs are in the
normal domain (positive values), and xi/eta are both positive and negative
(small) offsets. this_ra came up as negative (but as I mentioned it was
the correct value).
cheers,
Ed
On Thu, 5 Jan 2006, Tim Jenness wrote:
> This one is a bit odd....
>
> I've got an NDF with and RA of 18h but when I run stats on it it reports that
> the RA is -6h. If I use "ndftrace fullframe" the bounds of the image come out
> correctly with positive RA.
>
> Do other people see this? This seems to have been around for a while...
>
> Test image at http://www.jach.hawaii.edu/~timj/test.sdf.gz
>
>
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