MOPEX User's Guide - IRSA

Chapter 5. Mosaicking (mosaic.pl)
MOPEX User’s Guide
The Mosaic pipeline performs interpolation and co-addition of FITS images. In Spitzer terms, the
software takes the individual Basic Calibrated Data (BCD) frames and combines them to create a
mosaic of the observed region. There is a choice of interpolation and co-addition schemes, and
the package also carries out the user's choice of outlier rejection to remove cosmic rays and bad
pixels. Three main files are output by the package: a mosaic of the input BCDs, a coverage map
showing how many of the input frames were rejected, and an uncertainty mosaic showing the
uncertainties in each output pixel.
5.1 Basic Input Requirements
In order to carry out a basic mosaicking, MOPEX will expect some or all of the following files as
input. See Chapter 3 on MOPEX Input for more information on the format of these files.
• A text file containing a list of input data images (e.g. Spitzer BCD frames; required)
• A text file containing a list of input uncertainty images (optional)
• A text file containing a list of input status mask images (optional)
• A mask image flagging permanently damaged pixels in the detector (PMask; optional)
• A "namelist" file specifying the parameters to be used for mosaicking (Command-Line
MOPEX only; required)
5.2 Running Mosaic
To load a standalone Mosaic pipeline (i.e. without appending to an existing Overlap pipeline),
either start from a MOPEX template namelist (File > New Mosaic Pipeline), load an existing
Mosaic namelist file (File > Read Name List) or load an empty flow and insert a Mosaic pipeline
from there (File > New Empty MOPEX Pipeline, then go to Insert Mosaic at the top of the flow
window and choose Empty Pipeline). If you choose the last option, MOPEX will load an empty
Mosaic flow to which you can add and subtract modules, and modify the input parameters.
To append a Mosaic pipeline to the end of an existing Overlap pipeline so that you can use the
background-corrected images as input, click on the Insert Mosaic rectangular button at the top of
the Overlap window. This will pull up a dialogue box giving you three options. Choose From File
to load a previously-created namelist from file, From Template to start from one of the inbuilt
Mosaic templates, and Empty Pipeline to open an empty Mosaic flow that you can build up by
Mosaicking (mosaic.pl) 45
Basic Input Requirements