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.