MCOVERAGECHECK(1)

NAME
mCoverageCheck - Filter an image metadata table down to those records representing FITS files that overlap a footprint on the sky

SYNOPSIS
mCoverageCheck [-s statusfile] in.tbl out.tbl -mode <parameters>

DESCRIPTION
mCoverageCheck can be used to subset an image metadata table (containing FITS/WCS information or image corners) by determining which records in the table represent images that overlap with a region definition (box or circle in the sky) given on the command line.

OPTIONS

-s statusfile
    Output and errors are sent to statusfile instead of to stdout

-mode
    Can be one of:

          points (used to describe a convex polygon)
          box
          circle
          header (area is described in a header file)
          point (find images that overlap one particular point on the sky)
          cutout (operates like box mode, but returns metadata that represents what the input images would look like after being subset to exactly match the cutout area)

in.tbl
    Input metadata table.

out.tbl
    Output metadata table, to contain subset of in.tbl.

parameters
    Depends on mode as following:

          points: ra1 dec1 ra2 dec2 ... raN decN (must be at least 3 vertices)
          box: ra dec xsize [ysize [rotation]] where ra, dec is the center of the box, and size is in degrees.
          circle: ra dec radius where ra, dec is the center of the circle, and radius is in degrees (default is 0, in which case it's treated like a point search).
          point: ra dec
          header: region.hdr (path to an ASCII header template that defines the region of interest)
          cutout: ra dec xsize [ysize] where ra, dec is the center of the cutout area, and size is in degrees.

RESULT
The output file out.tbl is created, with nimages records.

MESSAGES

OK  [struct stat="OK", count=n]

ERROR
    Cannot open status file: statusfile

ERROR
    Invalid region definition mode: string

ERROR
    Too few vertices for region (must be at least three)

ERROR
    Longitude n (string) cannot be interpreted as a real number

ERROR
    Latitude n (string) cannot be interpreted as a real number

ERROR
    Failed to find bounding polygon for points

ERROR
    Too few arguments for box or cutout (must at least have center and size)

ERROR
    Center RA string (string) cannot be interpreted as a real number

ERROR
    Center Dec string (string) cannot be interpreted as a real number

ERROR
    X box size string (string) cannot be interpreted as a real number

ERROR
    X box size (string) must be a positive number

ERROR
    Y box size string (string) cannot be interpreted as a real number

ERROR
    Y box size (string) must be a positive number

ERROR
    Box rotation string (string) cannot be interpreted as a real number

ERROR
    Must give header file name

ERROR
    Failed to find bounding polygon for points

ERROR
    Too few arguments for circle (must at least have center)

ERROR
    Circle radius string (string) cannot be interpreted as a real number

ERROR
    Too few arguments for point (must have coordinates)

ERROR
    Point RA string (string) cannot be interpreted as a real number

ERROR
    Point Dec string (string) cannot be interpreted as a real number

ERROR
    Error opening table filename

ERROR
    Cannot create output file filename

ERROR
    Need either WCS or corner columns.

ERROR
    Failed to create wcs structure for record n

EXAMPLES

As input, we use this table of 2MASS atlas images. The images in this table are in two "clumps" on the sky: 3 overlapping images separated by several degrees from the other 12 overlapping images. Here we will show several ways of isolating the group of 3 images.

$ mCoverageCheck images.tbl circle.tbl -circle 262.78208 -35.03049 1.0
    [struct stat="OK", count="3"]

$ mCoverageCheck images.tbl box.tbl -box 262.84948 -34.81197 1.0
    [struct stat="OK", count="3"]

$ mCoverageCheck images.tbl points.tbl -points 263.3796 -34.48881 262.15127 -34.51032 262.90267 -35.38753
    [struct stat="OK", count="3"]

$ mCoverageCheck images.tbl point.tbl -point 262.78208 -35.03049
    [struct stat="OK", count="3"]

Each of these methods results in this output table containing only 3 records out of the original 15.

BUGS
The drizzle algorithm has been implemented but has not been tested in this release.

If a header template contains carriage returns (i.e., created/modified on a Windows machine), the cfitsio library will be unable to read it properly, resulting in the error: [struct stat="ERROR", status=207, msg="illegal character in keyword"]

It is best for the background correction algorithms if the area described in the header template completely encloses all of the input images in their entirety. If parts of input images are "chopped off" by the header template, the background correction will be affected. We recommend you use an expanded header for the reprojection and background modeling steps, returning to the originally desired header size for the final coaddition. The default background matching assumes that there are no non-linear background variations in the individual images (and therefore in the overlap differences). If there is any uncertainty in this regard, it is safer to turn on the "level only" background matching (the "-l" flag in mBgModel.

COPYRIGHT
2001-2015 California Institute of Technology, Pasadena, California

If your research uses Montage, please include the following acknowledgement: "This research made use of Montage. It is funded by the National Science Foundation under Grant Number ACI-1440620, and was previously funded by the National Aeronautics and Space Administration's Earth Science Technology Office, Computation Technologies Project, under Cooperative Agreement Number NCC5-626 between NASA and the California Institute of Technology."

The Montage distribution includes an adaptation of the MOPEX algorithm developed at the Spitzer Science Center.