Spitzer Documentation & Tools

Purpose and Description

MOPEX (MOsaicker and Point source EXtractor) is a package for reducing and analyzing imaging data, as well as MIPS SED data. MOPEX includes the point source extraction package, APEX.

MOPEX is designed to allow the user to:
  • perform sophisticated background matching of individual data frames
  • mosaic the individual frames downloaded from the Spitzer archive
  • perform both temporal and spatial outlier rejection during mosaicking
  • apply offline pointing refinement for MIPS data (refinement is already applied to IRAC data)
  • perform source detection on the mosaics using APEX
  • compute aperture photometry or PRF-fitting photometry for point sources
  • perform interpolation, coaddition, and spectrum extraction of MIPS SED images.

MOPEX comes in two different interfaces (GUI and command-line), both of which come packaged together. We recommend that all new users start with the GUI, which is more user-friendly than the command-line interface.


The MOPEX GUI is designed to allow the user to interactively set the many parameters in the processing modules, and then to examine the output of each step. Template parameter sets are available as a starting point, but users are strongly recommended to evaluate the process as it applies to their own data, as different datasets require different choices. The GUI includes module-by-module online help to allow easy access to the documentation.

While the GUI provides an interactive interface to access the MOPEX software, the underlying scripts and binaries are the same as those available in the command-line interface. The GUI incorporates the most commonly-used functionality, but there are a number of additional useful tools available on the command line.

Command-Line MOPEX

The command-line version of MOPEX consists of a set of Perl scripts that are called by the user from the command line. Some of these scripts aren't available in the GUI, but may be useful for data manipulation. Users are encouraged to check them before writing their own code; the scripts can be found in the MOPEX installation directory, under the subdirectory bin/. Experienced users, or those with large volumes of data, may prefer to use the command-line version of MOPEX since it is marginally faster and can be scripted.

Instructions for downloading and installing MOPEX.
Tracking updates to the MOPEX software
Known bugs in MOPEX