c This example shows how to read a data field in HDF-EOS5 grid data.

      program read_datafield_grid_OMI_Aura_L3_OMAEROe

      implicit none

      integer gridfile1
      integer grid1
      integer status
      integer datafield1rank(32)
      integer*4 datafield1dimsize(32)
      integer datafield1type(1)
      character*512 datafield1dimname
      character*512 datafield1maxdimname
      integer*2 datafield1data(1440,720)
      integer*4 datafield1start(2)
      integer*4 datafield1stride(2)
      integer*4 datafield1edge(2)
      integer*4 i, j
      integer he5_gdfldinfo, he5_gdrdfld, he5_gddetach, he5_gdopen,
     $  he5_gdclose, he5_gdattach
      external he5_gdfldinfo, he5_gdrdfld, he5_gddetach, he5_gdopen,
     $  he5_gdclose, he5_gdattach
      integer HE5F_ACC_RDONLY
      parameter (HE5F_ACC_RDONLY=101)

c Open 'OMI-Aura_L3-OMAEROe_2004m1001_v003-2009m0114t094640.he5' using
c  grid API
      gridfile1 = he5_gdopen
     $ ('OMI-Aura_L3-OMAEROe_2004m1001_v003-2009m0114t094640.he5',
     $  HE5F_ACC_RDONLY)

c Open a grid named 'ColumnAmountAerosol'
      grid1 = he5_gdattach(gridfile1, 'ColumnAmountAerosol')

c Retrieve information about 'TerrainReflectivity' datafield
      status = he5_gdfldinfo(grid1, 'TerrainReflectivity',
     $  datafield1rank, datafield1dimsize, datafield1type,
     $  datafield1dimname, datafield1maxdimname)
c Select necessary range of elements
      datafield1start(1) = 0
      datafield1stride(1) = 1
      datafield1edge(1) = 1440
      datafield1start(2) = 0
      datafield1stride(2) = 1
      datafield1edge(2) = 720
c Read data from 'TerrainReflectivity'
      status = he5_gdrdfld(grid1, 'TerrainReflectivity',
     $  datafield1start, datafield1stride, datafield1edge,
     $  datafield1data)
c Dump data from 'TerrainReflectivity'
      do i = 1, 7
        do j = 1, 14
          write(*,*), datafield1data(j,i)
        enddo
        write(*,*)
      enddo

c Close the grid named 'ColumnAmountAerosol'
      status = he5_gddetach(grid1)

c Close 'OMI-Aura_L3-OMAEROe_2004m1001_v003-2009m0114t094640.he5'
      status = he5_gdclose(gridfile1)

      end