man mCoverageCheck (1): 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.