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Data Reduction/Analysis

Data Reduction

The UIT standard data products were produced using the Batch Data Reduction (BDR) software system. The processing steps included: (1) linearization of the data, (2) flat-fielding, (3), geometric correction of image distortions, (4) astrometric solution (mapping to RA and Dec), and (5) point-source photometry. For some images, an astrometric solution was not possible so subsequent processing steps were not performed. See also the discussion of UIT Data Products. The data reduction and calibrations involved are described in more detail in the 1997 PASP paper. An analysis of the geometric correction was published by Greason et. al. 1994.


The UIT project archived three sets of software with the GSFC Archive (NDADS) with the UIT Astro 1 data. The UIT project has indicated that the software used for Astro 2 data was relatively unchanged. These software sets have been retrieved from NDADS (the updated MOUSSE software was provided by Wayne Landsman from Goddard Space Flight Center), and are available from MAST as gzipped tar files via anonymous ftp. The software packages were archived for documentation purposes and may require some revision to work outside the UIT project environment. The software is unsupported. Documentation is available as both postscript and tex files.

1. BDR Software

The Batch Data Reduction software, written in Fortran and C, was used to process UIT data and generate FITS output files.

bdr.tar.gz Gzipped UNIX tar file containing software used in UIT batch data processing. Includes programs in FORTRAN and C, associated data files and documentation.,
Description of BDR design and programs.,
Description of FITS headers.
readme_cal.txt Listing of calibration files used by the software.

2. Exported MOUSSE Software

The Multi-Option UIT Software System Environment was used by UIT team members to analyze their data. The programs are written in IDL and were meant to supplement the procedures contained in the ASTRON library.

export.tar.gz Gzipped UNIX tar file containing IDL procedures used by the UIT team to manipulate and analyze UIT images; a data base program; and an on-line help facility.,
Description of the IDL procedures used to display and manipulate UIT images. These are subset of IDL analysis system MOUSSE (Multi-Option UIT Software System Environment).,
Description of an IDL database system.,
Description of IDL routines for reading FITS table files.,
Description of IDL point-source photometry programs, based on DAOPHOT.,
A list of MOUSSE software likely to be used by interactive user.

3. IDL Version of BDR

This IDL version of the processing software was used for calibration and testing, such as quickly testing a sample characteristic curve on an image.

idlbdr.tar.gz Gzipped UNIX tar file of IDL procedures and supporting files used to process a UIT density image through photographic background subtraction, linearization and flat field division.

In addition, users may find some of the IDL procedures in the ASTRON library useful.