CGFINDMAPBOUNDARY

CGFINDMAPBOUNDARY
Utility routine to find the map projection grid boundary from a file,
if it is possible to do so. Currently works with GeoTIFF files, CF 1.4
compliant netCDF files, and GPD files created with the GPD_Viewer software
from the Catatlyst Library.

Returns

The return value is either a 1, indicating a boundary can be found, or a 0 indicating
that the boundary could not be found.

Params

filename: in, required, type='string'
The name of a filename to open to see if a projected map grid boundary can be found.
boundary: out, optional, type=float
The boundary of the image in projected meter space, in the form [x0,y0,x1,y1].

Keywords

use_latlon: in, optional, type=boolean, default=0
If the filename is a netCDF file, set this keyword to force the boundary
to be determined by reading the include latitude/longitude arrays.
utm_south: in, optional, type=boolean, default=0
Set this keyword to add 10e6 to each of the Y values. This is sometimes
necessary with LandSat images in the Southern hemisphere, where the Y values
are given in negative values to indicate southern UTM zones.
xrange: out, optional, type=float
A two element vector: boundary[[0,2]]
yrange: out, optional, type=float
A two element vector: boundary[[1,3]]

Author

FANNING SOFTWARE CONSULTING::
David W. Fanning
1645 Sheely Drive
Fort Collins, CO 80526 USA
Phone: 970-221-0438
E-mail: david@idlcoyote.com
Coyote's Guide to IDL Programming: http://www.idlcoyote.com

History

Written by: David W. Fanning, 23 February 2010.::
Added XRANGE and YRANGE keywords. 25 February 2010. DWF
Added USE_LATLON keyword for finding boundary of netCDF files containing latitude
and longitude arrays. 6 April 2010. DWF.
Added UTM_SOUTH keyword to handle Landsat dat in UTM projections in GeoTiff files
that have to have 10e6 added to Y values to make them work in IDL. 14 Aug 2012. DWF.
Renamed cgFindMapBoundary from FindMapBoundary. 21 Aug 2012. DWF.
Changed reference to NCDF_Coord to cgNCDFMap. 28 Oct 2012. DWF.