Extracting PSF Images
We have created a standalone code that serves to both read them and as a
template library for inclusion in other codes. The code is available as: readAtlasImages-v5_4_11.tar.gz.
1. % make clean
2. % make
If you are on a big-endian machine, remove -DSDSS_LITTLE_ENDIAN from
CFLAGS in the Makefile.
% read_PSF -h
Usage: read_PSF [options] input-file hdu output-file
Your options are:
-? This message
-h This message
-i Print an ID string and exit
-v Turn up verbosity (repeat flag for more chatter)
To reconstruct the z PSF (i.e. the 5th HDU) at the position (row, col) =
(500, 600) from run 1336, column 2, field 51 you'd say:
% read_PSF psField-001336-2-0051.fit 5 500.0 600.0 foo.fit
The desired PSF would appear as an unsigned short FITS file in foo.fit;
the background level is set to the standard `soft bias' of 1000. If you want
a floating image, change a line in the read_PSF.c; look for
/* create a float region */
The standalone programs read_atlas_image (reads fpAtlas files) and
read_mask (reads fpM files) are similar. All three are built by the
same 'make' command.
I don't expect that many users will actually want to use the
read_PSF executable (although it is perfectly functional). The main
use of the product will probably be to link into custom built executables
that need to process atlas image data. I believe that the code should be
easily reused for this purpose.
Last modified: Fri Jun 23 14:02:15 BST 2006