I am attempting to warp a GTiff from a lat/lon projection to a higher (~2x) resolution Polar Stereographic grid.

In the output GTiff any cells north of 64 deg lat become NaN instead of their actual values.

I am using gdalwarp thusly:

  gdalwarp -t_srs 'wkt string here' -tr 5000 5000 -te -4252339.5,-5302590.0,4597660.5,2747410.25 in.tif out.tif

What could be causing the output raster to have the blank area?

Input extents are [-84.84, -50.19, 55.07, 79.96]. [minLon,maxLon,minLat,maxLat]

Output Coordinate system:

proj4 (+proj=stere +lat_0=90 +lat_ts=60 +lon_0=-100 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs) .

It's standard Polar Stereographic but with Central Meridian at -100 deg and latitude of origin at 60 deg.

The issue was caused by the large difference in coordinate systems. (The domain was self-intersecting in one of the coord systems). It was largely solved by explicitly entering the output extent instead of having GDAL attempt to guess it.

i.e -te -180 0 180 90 was added to the gdalwarp line.

  • 1
    Can you add the extents of the input geotiff? – mkennedy Feb 12 '15 at 22:02
  • 1
    And the target CRS? Is there a WKID (versus posting the WKT)? I'd like to try to reproduce the conversion in other software. – mkennedy Feb 12 '15 at 22:20
  • Input extents are [-84.84, -50.19, 55.07, 79.96] – JFerg Feb 13 '15 at 20:49

It works for me with a two-step-transformation:

gdalwarp -overwrite -t_srs "+proj=stere +lat_0=90 +lat_ts=60 +lon_0=-100 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs" -of GTiff D:\Download\NEU\ster-wgs84.tif D:/Download/NEU/ster-100-transformed.tif
gdalwarp -overwrite -wo SAMPLE_STEPS=1000 -t_srs "+proj=stere +lat_0=90 +lat_ts=60 +lon_0=-100 +k=1 +x_0=0 +y_0=0 +ellps=WGS84 +datum=WGS84 +units=m +no_defs" -tr 5000 5000 -te -4252339.5 -5302590.0 4597660.5 2747410.25 ster-100-transformed.tif out.tif

A reason might be that your target extent crosses the 180° line, making the extent a self-intersecting polygon in the source srs WGS84:

enter image description here

enter image description here

| improve this answer | |

Try with larger number of sample steps -wo SAMPLE_STEPS=1000

Reprojecting Natural Earth raster into natearth projection with gdalwarp causing black squares?

Or with lower error threshold -et 0.01

gdalwarp leaves horizontal artifacts regridding from EASE-Grid (laea) to Polarstero (stere)

| improve this answer | |

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