Georeferencing Himawari-8 in GDAL (or other)

Question

Does anyone know the appropriate project information to georeference (and hence reproject) Himawari-8 AHI data in the IR? The images are 5500x5500 pixels.

Currently I try these:

ulx=-5570248.832537 
uly=5570248.832537 
lrx=5567248.429179 
lry=-5567248.429179 
gdal_translate -a_srs  "+proj=geos +a=6378169 +b=6356583.8 +lon_0=140.7 +h=35785831" -a_ullr $ulx $uly $lrx $lry HDF5:"TEST"://img tmp.tif

gdalwarp -srcnodata -32767 -s_srs '+proj=geos +lon_0=140.7 +h=35785831 +x_0=0.0' -t_srs '+proj=latlong +datum=WGS84' -tr 0.03 0.03 -te 55.7 -80 225.7 80 -order 3 tmp.tif FINAL.tif

This, however, results in an image that's not quite right. Australia and Indonesia almost match a coastline boundary overlay but as one moves further from the subsatellite point there exists a larger and larger offset. See this comparison image:

If someone could point me to the correct code to use for reprojection that would be great. I suspect it's the a_ullr values that I have wrong.

Answer 1

Your assumption is right, you need the correct values for the corner coordinates.

Since the source image is slightly larger than the Earth, you can not simply reproject the corner coordinates. You may use a different approach:

According to the project site, the 5500x5500pix data is providing a 2km resolution on the center. So the extent from the center is 5500/2*2000m = +/-5500000m.

With that, and the WGS84 ellipsoid data, I used this transformation:

gdal_translate -a_srs "+proj=geos +h=35785863 +a=6378137.0 +b=6356752.3 +lon_0=140.7 +no_defs" -a_ullr -5500000 5500000 5500000 -5500000 PI_H08_20150125_0230_TRC_FLDK_R10_PGPFD.png temp.tif
gdalwarp -overwrite -t_srs "+proj=latlong +ellps=WGS84 +pm=140.7" -wo SOURCE_EXTRA=100 temp.tif Himawari8.tif