Reduction software

The IRAF package has been upgraded further with the addition of an optional software suppression of the dc-gradient in the script that makes master flats from differential twilight flats, while the the imaging reduction scripts for normal and beam-switch mode can now work even though no stars are found for alignment. In this case the coordinates will be used for alignment, giving a slightly worse registration. Trimming of images is set as an option.

The documentation of how the package works, which is found in the section ``Reductions'' in the NOTCam User's Guide, was updated. See:

The reduction package will be developed further to include tasks to reduce an ABBA spectroscopic observation and to reduce polarimetric imaging. Also, the handling of bad pixels will be improved in all routines.

Thomas Augusteijn 2009-05-14