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.
Utility
The return value is either a 1, indicating a boundary can be found, or a 0 indicating that the boundary could not be found.
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].
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]]
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
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.
Copyright (c) 2012, Fanning Software Consulting, Inc.