c This example shows how to read a data field and two geo-location
c  fields in HDF-EOS5 swath data.

      program read_fields_swath_OMI_Aura_L2_OMAERO

      implicit none

      integer swathfile1
      integer swath1
      integer status
      integer datafield1rank(32)
      integer*4 datafield1dimsize(32)
      integer datafield1type(1)
      character*512 datafield1dimname
      character*512 datafield1maxdimname
      integer*2 datafield1data(60,1644)
      integer*4 datafield1start(2)
      integer*4 datafield1stride(2)
      integer*4 datafield1edge(2)
      integer geofield1rank(32)
      integer*4 geofield1dimsize(32)
      integer geofield1type(1)
      character*512 geofield1dimname
      character*512 geofield1maxdimname
      real*4 geofield1data(60,1644)
      integer*4 geofield1start(2)
      integer*4 geofield1stride(2)
      integer*4 geofield1edge(2)
      integer geofield2rank(32)
      integer*4 geofield2dimsize(32)
      integer geofield2type(1)
      character*512 geofield2dimname
      character*512 geofield2maxdimname
      real*4 geofield2data(60,1644)
      integer*4 geofield2start(2)
      integer*4 geofield2stride(2)
      integer*4 geofield2edge(2)
      integer*4 i, j
      integer he5_swfldinfo, he5_swrdfld, he5_swdetach, he5_swopen,
     $  he5_swclose, he5_swattach
      external he5_swfldinfo, he5_swrdfld, he5_swdetach, he5_swopen,
     $  he5_swclose, he5_swattach
      integer HE5F_ACC_RDONLY
      parameter (HE5F_ACC_RDONLY=101)

c Open 'OMI-Aura_L2-OMAERO_2004m1001t0003-o01132_v003.he5' using swath
c  API
      swathfile1 = he5_swopen
     $ ('OMI-Aura_L2-OMAERO_2004m1001t0003-o01132_v003.he5',
     $  HE5F_ACC_RDONLY)

c Open a swath named 'ColumnAmountAerosol'
      swath1 = he5_swattach(swathfile1, 'ColumnAmountAerosol')

c Retrieve information about 'AerosolIndexUV' datafield
      status = he5_swfldinfo(swath1, 'AerosolIndexUV', datafield1rank,
     $  datafield1dimsize, datafield1type, datafield1dimname,
     $  datafield1maxdimname)
c Select necessary range of elements
      datafield1start(1) = 0
      datafield1stride(1) = 1
      datafield1edge(1) = 60
      datafield1start(2) = 0
      datafield1stride(2) = 1
      datafield1edge(2) = 1644
c Read data from 'AerosolIndexUV'
      status = he5_swrdfld(swath1, 'AerosolIndexUV', datafield1start,
     $  datafield1stride, datafield1edge, datafield1data)
c Dump data from 'AerosolIndexUV'
      do i = 1, 16
        do j = 1, 6
          write(*,*), datafield1data(j,i)
        enddo
        write(*,*)
      enddo

c Retrieve information about 'Longitude' geolocation field
      status = he5_swfldinfo(swath1, 'Longitude', geofield1rank,
     $  geofield1dimsize, geofield1type, geofield1dimname,
     $  geofield1maxdimname)
c Select necessary range of elements
      geofield1start(1) = 0
      geofield1stride(1) = 1
      geofield1edge(1) = 60
      geofield1start(2) = 0
      geofield1stride(2) = 1
      geofield1edge(2) = 1644
c Read data from 'Longitude'
      status = he5_swrdfld(swath1, 'Longitude', geofield1start,
     $  geofield1stride, geofield1edge, geofield1data)
c Dump data from 'Longitude'
      do i = 1, 16
        do j = 1, 6
          write(*,*), geofield1data(j,i)
        enddo
        write(*,*)
      enddo

c Retrieve information about 'Latitude' geolocation field
      status = he5_swfldinfo(swath1, 'Latitude', geofield2rank,
     $  geofield2dimsize, geofield2type, geofield2dimname,
     $  geofield2maxdimname)
c Select necessary range of elements
      geofield2start(1) = 0
      geofield2stride(1) = 1
      geofield2edge(1) = 60
      geofield2start(2) = 0
      geofield2stride(2) = 1
      geofield2edge(2) = 1644
c Read data from 'Latitude'
      status = he5_swrdfld(swath1, 'Latitude', geofield2start,
     $  geofield2stride, geofield2edge, geofield2data)
c Dump data from 'Latitude'
      do i = 1, 16
        do j = 1, 6
          write(*,*), geofield2data(j,i)
        enddo
        write(*,*)
      enddo

c Close the swath named 'ColumnAmountAerosol'
      status = he5_swdetach(swath1)

c Close 'OMI-Aura_L2-OMAERO_2004m1001t0003-o01132_v003.he5'
      status = he5_swclose(swathfile1)

      end