c This example shows how to read a data field and two geo-location
c  fields in HDF-EOS2 swath data.

      program read_fields_swath_NOAA_17_AMSU

      implicit none

      integer*4 swathfile1
      integer*4 swath1
      integer status
      integer*4 datafield1rank(32)
      integer*4 datafield1dimsize(32)
      integer*4 datafield1type(1)
      character*512 datafield1dimname
      real*4 datafield1data(30,783)
      integer*4 datafield1start(2)
      integer*4 datafield1stride(2)
      integer*4 datafield1edge(2)
      integer*4 geofield1rank(32)
      integer*4 geofield1dimsize(32)
      integer*4 geofield1type(1)
      character*512 geofield1dimname
      real*4 geofield1data(30,783)
      integer*4 geofield1start(2)
      integer*4 geofield1stride(2)
      integer*4 geofield1edge(2)
      integer*4 geofield2rank(32)
      integer*4 geofield2dimsize(32)
      integer*4 geofield2type(1)
      character*512 geofield2dimname
      real*4 geofield2data(30,783)
      integer*4 geofield2start(2)
      integer*4 geofield2stride(2)
      integer*4 geofield2edge(2)
      integer*4 i, j
      integer swrdfld, swfldinfo, swdetach, swclose
      external swrdfld, swfldinfo, swdetach, swclose
      integer*4 swopen, swattach
      external swopen, swattach
      integer*4 DFACC_READ
      parameter (DFACC_READ=1)

c Open 'amsua17_2003.007_02805_2302_0046_GC.eos' using swath API
      swathfile1 = swopen('amsua17_2003.007_02805_2302_0046_GC.eos',
     $  DFACC_READ)

c Open a swath named 'Orbit 2805'
      swath1 = swattach(swathfile1, 'Orbit 2805')

c Retrieve information about '23800.37 MHz' datafield
      status = swfldinfo(swath1, '23800.37 MHz', datafield1rank,
     $  datafield1dimsize, datafield1type, datafield1dimname)
c Select necessary range of elements
      datafield1start(1) = 0
      datafield1stride(1) = 1
      datafield1edge(1) = 30
      datafield1start(2) = 0
      datafield1stride(2) = 1
      datafield1edge(2) = 783
c Read data from '23800.37 MHz'
      status = swrdfld(swath1, '23800.37 MHz', datafield1start,
     $  datafield1stride, datafield1edge, datafield1data)
c Dump data from '23800.37 MHz'
      do i = 1, 20
        do j = 1, 2
          write(*,*), datafield1data(j,i)
        enddo
        write(*,*)
      enddo

c Retrieve information about 'Longitude' geolocation field
      status = swfldinfo(swath1, 'Longitude', geofield1rank,
     $  geofield1dimsize, geofield1type, geofield1dimname)
c Select necessary range of elements
      geofield1start(1) = 0
      geofield1stride(1) = 1
      geofield1edge(1) = 30
      geofield1start(2) = 0
      geofield1stride(2) = 1
      geofield1edge(2) = 783
c Read data from 'Longitude'
      status = swrdfld(swath1, 'Longitude', geofield1start,
     $  geofield1stride, geofield1edge, geofield1data)
c Dump data from 'Longitude'
      do i = 1, 20
        do j = 1, 2
          write(*,*), geofield1data(j,i)
        enddo
        write(*,*)
      enddo

c Retrieve information about 'Latitude' geolocation field
      status = swfldinfo(swath1, 'Latitude', geofield2rank,
     $  geofield2dimsize, geofield2type, geofield2dimname)
c Select necessary range of elements
      geofield2start(1) = 0
      geofield2stride(1) = 1
      geofield2edge(1) = 30
      geofield2start(2) = 0
      geofield2stride(2) = 1
      geofield2edge(2) = 783
c Read data from 'Latitude'
      status = swrdfld(swath1, 'Latitude', geofield2start,
     $  geofield2stride, geofield2edge, geofield2data)
c Dump data from 'Latitude'
      do i = 1, 20
        do j = 1, 2
          write(*,*), geofield2data(j,i)
        enddo
        write(*,*)
      enddo

c Close the swath named 'Orbit 2805'
      status = swdetach(swath1)

c Close 'amsua17_2003.007_02805_2302_0046_GC.eos'
      status = swclose(swathfile1)

      end