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mExec - Online in the Cloud

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This is the command mExec that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator



mExec - Create a 2MASS, SDSS or DSS mosaic based on a size and location


mExec [-r rawdir] [-n ntilex] [-m ntiley] [-l] [-k] [-c] [-o output.fits] [-d level] [-f
region.hdr | -h header] survey band [workspace-dir]


The mExec module is a mosaicking executive for 2MASS, SDSS, and DSS data. It includes
remote data and metadata access. Alternatively, users can mosaic a set of data already on


-r rawdir
Provide path to directory containing original ("raw") data which will be
reprojected and mosaicked. Not necessary if using mExec to retrieve remote data
from the 2MASS, SDSS or DSS surveys.

-n ntilex
Number of output tiles to create along the X-axis - default is 1 for a single
mosaicked image.

-m ntiley
Number of output tiles to create along the Y-axis - default is equal to ntilex.

-l "Level-only" flag (see mBgModel)

-k If retrieving data from a remote archive, the "keep" flag will leave the original
data products on disk after generating a mosaic. Without this flag, raw data will
be deleted (unless it was provided by the user with the "-r" flag).

-c Remove all temporary files and intermediate data products. Note: if not using the
'-o' flag to specify an output file, this will also remove mosaic.fits.

-o output.fits
Provide your own filename for the output mosaic. Default filename is

-d level
Print out additional debugging information (levels 1-4)


mExec must be provided with FITS header information. This can be in the form of a header
template ("-f" flag), or the user can pass header text directly to the program ("-h"

-f region.hdr
Path to header template used to create mosaic.

-h header

Provide header template as text input rather than point to a file; see sample shell
script that makes use of this option.

survey band
If not mosaicking user-provided data ("-r" flag), must select one of the following
combinations of survey and band:

2MASS [j, h, k]
SDSS [u, g, r, i, z]

Directory where intermediate files will be created. If no workspace is given, a
unique local subdirectory will be created (e.g.; ./MOSAIC_AAAaa17v)


[struct stat="OK", workspace="workspace-dir"]

The output mosaic(s), and any intermediate files (if the "-c" flag was not used) will be
inside workspace-dir.


OK [struct stat="OK", workspace="workdir"]

ERROR Must have either header file (-f) or header text (-h)

ERROR Can't open original header template file: [region.hdr]

ERROR Can't open workspace header template file: [region.hdr]

ERROR Can't create proper subdirectories in workspace (may already exist)

ERROR Can't open header template file

ERROR Can't open expanded header file: [big_region.hdr]

ERROR survey has no data covering expanded area

ERROR survey has no data covering this area

ERROR No data was available for the region specified at this time

ERROR Bad WCS in input image

ERROR Can't open mosaic file: [mosaic.fits]

ERROR Can't open save file: [image.fits]

ERROR Output wcsinit() failed

ERROR Error from another Montage module


To create a small mosaic of the area around m31, located at coordinates "10.68469

$ mHdr m31 0.3 m31.hdr
[struct stat="OK", count="16"]

$ mExec -o m31.fits -f m31.hdr 2MASS J tempdir
[struct stat="OK", workspace="/path/to/tempdir"]

To mosaic your own collection of data, contained in the directory "raw":

$ mImgtbl raw raw.tbl
[struct stat="OK", count=16, badfits=0]

$ mMakeHdr raw.tbl raw.hdr

[struct stat="OK", count=16, clon=0.118289, clat=0.118288, lonsize=0.236660,
latsize=0.236660, posang=359.999756, lon1=0.236618, lat1=-0.000042,
lon2=359.999959, lat2=-0.000041, lon3=359.999959, lat3=0.236618, lon4=0.236620,

$ mExec -o my_mosaic.fits raw.hdr workdir
[struct stat="OK", workspace="/path/to/workdir"]

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