Re: Odd issue with master bias and dark frames
Posted by
karenacollins on
Jun 01, 2021; 4:27am
URL: http://astroimagej.170.s1.nabble.com/Odd-issue-with-master-bias-and-dark-frames-tp1579p1580.html
Hi Mike,
I also see the problem you are seeing when attempting to open the
mdark_1.497_2x2.fits file you provided using the latest AIJ daily
build. However, if I rebuild the master from the 10 darks you
provided the new master dark opens as expected. Can you let us know
which version of AIJ you used to create the master dark (use =>
AIJ_Toolbar => Help => About AstroImageJ)? Also, if you are
not using the latest "Daily Build", could you please update to the
daily build using
these
instructions and let know if the problem persists.
Karen
On 5/31/2021 12:51 PM, Michael Collins
[via AstroImageJ] wrote:
While doing some engineering work over the weekend, I captured
sets of bias and dark frames intended to calibrate my on-sky
images. I've done this before using other cameras and capture
software, so the process is reasonably familiar to me. Looking at
my data afterward, I encountered no difficulty nor saw any error
or warning messages when the master bias and dark frames were
generated. I'm unable to use the masters to calibrate the image
sets, however -- they are rejected with the message: "Unable to
open FITS file <path/filename>: IO error:
java.io.IOException: Invalid FITS header", followed by an "open
failed" dialog. The first error is also reported if I attempt to
open any of the master images using File -> Open... ds9 does
not report any problems with any of the masters, and inspection of
the header data using imhead shows no obvious problem, though I
note that BITPIX is 16 in the original FITS headers and -32 in the
masters.
A set of darks and the corresponding master are available in
<https://tmckepsj.org/files/Dark_1.497.tgz>.
Not sure what I'm doing wrong, but I'd be interested in learning.
-- Mike --
--
Michael Collins
Instrumentation Group
Lowell Observatory
Flagstaff, Arizona