Installation Instructions for DRIZZLE V1.2

Richard Hook (ST-ECF, ESO)
Andrew Fruchter (STScI)

Original version September 1996
Revised for V1.1, February and May 1997
V1.2 release, March 1998

This file contains instructions for compiling, linking and installing
the F77/VOS IRAF tasks "drizzle" which implemented the drizzling
method for the reconstruction of dithered images and "blot" which is
the reverse of drizzling 

It is assumed that the distribution compressed tar file has been
unpacked and that the resulting files are in the current directory.
The following should be present:

README                  Brief introduction
RELEASE_NOTES_V1.1      Release notes for V1.1
RELEASE_NOTES_V1.2      Release notes for V1.2
INSTALL                 This file, installation instructions
compile_drizzle         A single line script for compilation and linking
drizzle.f               The F77 source code
drizzle.hlp             An IRAF style help file for drizzle
drizzle.hlp-txt         An IRAF style help file for drizzle (text version)
drizzle.par             The IRAF parameter file for the drizzle task
compile_blot            A single line script for compilation and linking
blot.f                  The F77 source code
blot.hlp                An IRAF style help file for blot
blot.hlp-txt            An IRAF style help file for blot (text version)
blot.par                The IRAF parameter file for the blot task
drutil.f                Utility routines used by DRIZZLE & BLOT
x_drizzle.x             A single line of SPP needed for linking drizzle
x_blot.x                A single line of SPP needed for linking blot

there will also be a directory called "coeffs" which should contain
four text files of geometric distortion coefficients appropriate for
the WFPC2 and STIS on the HST and a README file.

Before the tasks can be built the files compile_drizzle and compile_blot
should be edited so that the correct location of the libiraf77.a and 
libiminterp.a files are specified. The first of these is normally in the 
"lib" directory of the local STSDAS installation and the latter in the 
standard IRAF libraries directory.  If they is not present then the tasks
cannot be installed. If in doubt consult your local IRAF manager. Ensure that 
compile_drizzle and compile_blot are executable and then run them by typing 
their names. If there are any error messages then there is most likely a 
problem with either your installation of IRAF or the local F77 compiler and 
your local system administrator should be consulted.

It is recommended that these tasks should be installed under IRAF 2.11.1
but other versions should also work.

Once "drizzle.e" and "blot.e" have been created it is necessary to install 
the tasks in IRAF. This is done using the following IRAF cl commands:

set drizzle=<the location of the drizzle and blot files>
task drizzle = drizzle$drizzle.e
task blot = drizzle$blot.e

These may be put into an IRAF startup file (eg, loginuser.cl) so that
they do not need to be typed each time IRAF is run.

When IRAF is started again the drizzle and blot tasks should be 
available and may be tested.

The help files may be displayed within IRAF using the commands:

help drizzle$drizzle.hlp fi+
help drizzle$blot.hlp fi+

The outputs of these commands are supplied as drizzle.hlp-txt and 
blot.hlp-txt.

Unfortunately we do not have the resources to provide full support. However, 
we are keen to help you make best use of these tasks to process your data 
and will be willing to answer queries and bug-reports as best we can. 
Drizzle and Blot are now also available within the "dither" package
in STSDAS.

rhook@eso.org,fruchter@stsci.edu 2nd March 1997