DSET data.dat
 XDEF 144 LINEAR 0.000000 2.500000
 YDEF 12 LINEAR 60.000000 2.500000
 ZDEF 1 LEVELS 850 
 TDEF 1 LINEAR 12:00Z01dec2018 1dy
 UNDEF  2e+20
 VARS  1
 H    1  y,x  GEOPOTENTIAL HEIGHT ON P LEV/P GRID  [m]
 ENDVARS