gdalwarp reprojection causes missing data

Question

I have tried to reproject and resample an SRTM DEM file from WGS84 to a cylindrical equal area projection. The problem is there is missing data as seen in the image below. The command I use is:

gdalwarp -s_srs WGS84 -t_srs ogcwkt.prj -r near -multi -ts 43200 0 topo30.ers topo30_equal_area.tif

with the ogcwkt.prj file content:

PROJCS["World_Cylindrical_Equal_Area",GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137.0,298.257223563]],PRIMEM["Greenwich",0.0],UNIT["Degree",0.0174532925199433]],PROJECTION["Cylindrical_Equal_Area"],PARAMETER["false_easting",0.0],PARAMETER["false_northing",0.0],PARAMETER["central_meridian",0.0],PARAMETER["standard_parallel_1",0.0],UNIT["Meter",1.0]]

enter image description here

I have tried several variations but none work. gdalinfo of the file gives me: Note the strange coordinate in Lower Left and Lower Right corners.

Driver: GTiff/GeoTIFF
Files: topo30_equal_area.tif
       topo30_equal_area.tif.aux.xml
Size is 43200, 13717
Coordinate System is:
PROJCS["World_Cylindrical_Equal_Area",
    GEOGCS["GCS_WGS_1984",
        DATUM["D_WGS_1984",
            SPHEROID["WGS_1984",6378137,298.257223563]],
        PRIMEM["Greenwich",0],
        UNIT["degree",0.0174532925199433]],
    PROJECTION["Cylindrical_Equal_Area"],
    PARAMETER["standard_parallel_1",0],
    PARAMETER["central_meridian",0],
    PARAMETER["false_easting",0],
    PARAMETER["false_northing",0],
    UNIT["metre",1,
        AUTHORITY["EPSG","9001"]]]
Origin = (-20037506.530948571860790,6360746.183380804955959)
Pixel Size = (927.657908734666648,-927.657908734666648)
Metadata:
  AREA_OR_POINT=Area
Image Structure Metadata:
  INTERLEAVE=BAND
Corner Coordinates:
Upper Left  (-20037506.531, 6360746.183) (179d59'59.94"W, 88d12'30.00"N)
Lower Left  (-20037506.531,-6363937.351) (179d59'59.94"W,-2147483648d-2147483648'  nan"N)
Upper Right (20037315.126, 6360746.183) (179d59'53.75"E, 88d12'30.00"N)
Lower Right (20037315.126,-6363937.351) (179d59'53.75"E,-2147483648d-2147483648'  nan"N)
Center      (     -95.702,   -1595.584) (  0d 0' 3.09"W,  0d 0'51.95"S)
Band 1 Block=43200x1 Type=Int16, ColorInterp=Gray
  Description = Topography
  Min=-10500.000 Max=7729.000 
  Minimum=-10500.000, Maximum=7729.000, Mean=-1911.637, StdDev=2643.966
  Unit Type: meters
  Metadata:
    STATISTICS_MAXIMUM=7729
    STATISTICS_MEAN=-1911.6374294607
    STATISTICS_MINIMUM=-10500
    STATISTICS_STDDEV=2643.9655969462

You might have to clip the source so that the poles are excluded before reprojection. — AndreJ, Jul 01 '15 at 07:48
Thanks AndreJ. I clipped the projection and it worked. I'll post the solution below. — Jacques MALAPRADE, Jul 01 '15 at 08:07

score 2 · Answer 1 · answered Jul 01 '15 at 08:13

gdalwarp had a problem projecting the poles using this projection. The solution came from AndreJ above which pointed me to clip the polar regions out of the input data. I ran the following commands which made it work:

>> gdal_translate -projwin -180 80 180 -80 topo30.ers topo30_no_poles.tif
>> gdalwarp -s_srs WGS84 -t_srs ogcwkt.prj -r near -multi topo30_no_poles.tif topo30_equal_area.tif

I now have a SRTM DEM of the globe in cylindrical equal area projection.

gdalwarp reprojection causes missing data

1 Answers1