[gdal-dev] "ERROR 1: tolerance condition error" when projecting to gnomonic

[Michal Migurski]

Hello,

I'm running into some problems warping to gnomonic projection. I'm trying to warp a TIFF in azimuthal-equidistant projection (covering North America, including the north pole and centered on 46°N, 95°W) to gnomonic. These are the relevant details and coverage of the input TIFF:
	http://dpaste.com/hold/372063/

Here's what I'm trying:
	gdalwarp -t_srs "+proj=gnom +lat_0=0 +lon_0=0" -te -6378137 -6378137 6378137 6378137 -ts 512 512 NAPHY_r-latlon.tif NAPHY_r-gnom.tif

Here's what I'm seeing:
	ERROR 1: tolerance condition error
	ERROR 1: tolerance condition error
	...
	ERROR 1: tolerance condition error
	ERROR 1: Reprojection failed, err = -20, further errors will be supressed on the transform object. 

The output looks to be a black square. I've successfully reprojected this same input TIFF to both spherical mercator and latlon, so I tried converting to one of those first and then gnomonic second, but still got the same errors. For what it's worth, the geographic info for the projected all-black TIFF looks right:
	http://dpaste.com/hold/372080/

I found this from six years ago and tried adding the recommended -wo SOURCE_EXTRA=100 -wo SAMPLE_GRID=YES parameters to gdalwarp, but I'm still seeing the same tolerance condition errors:
	http://trac.osgeo.org/gdal/ticket/642

Any ideas?

-mike.

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michal migurski- mike at stamen.com
                 415.558.1610