[gdal-dev] problem with HDF format

[Luca Delucchi]

Hi devs,

probably we found a problem with GDAL and HDF format, we are trying to
merge several MODIS tiles but we got a wrong "Corner Coordinates"

These are our input files

gdalinfo MOD11A1.A2012340.h29v05.005.2012342062359.hdf
 GRINGPOINTLATITUDE.1=39.9958333333333, 39.9958333333333,
30.0041666666667, 30.0041666666667
 GRINGPOINTLONGITUDE.1=143.594796204465, 156.637998651088,
138.5660967488, 127.027721580114

gdalinfo MOD11A1.A2012340.h28v05.005.2012342062414.hdf
  GRINGPOINTLATITUDE.1=39.9958333333333, 39.9958333333333,
30.0041666666667, 30.0041666666667
  GRINGPOINTLONGITUDE.1=130.54074741744, 143.583922543306,
127.018104673762, 115.479756825833

gdalinfo MOD11A1.A2012340.h28v04.005.2012342062356.hdf
  GRINGPOINTLATITUDE.1=49.9958333333333, 49.9958333333333,
40.0041666666667, 40.0041666666667
  GRINGPOINTLONGITUDE.1=155.572379857539, 171.116660974438,
143.601448808716, 130.556661758206

but using gdalbuildvrt, gdal_merge and gdalwarp we got a bigger upper
right value (173.313142 instead 171.116660974438), you can see our
tests here [0]

do you have any idea? is it a bug or feature?

[0] http://pastebin.com/KGYvFtfn

-- 
ciao
Luca

www.lucadelu.org