c  written by Vern Kousky 10/29/13
c  Program to compute ave. cloud brightness temps. for 1.75 deg boxes
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      parameter (imax=1000,jmax=1000,nobs1=864,nobs2=2040)
      dimension x(imax,jmax),xave(40,40),y(40,40)
      character path*33
      data path/'/cpc/home/wd52vk/samer/satellite/'/
      open (11,file=path//'irwin-SA-1jan-18apr1993'
     *,access='direct',form='unformatted',recl=imax*jmax*4)
      open (12,file=path//'irwin-SA-21apr-31dec1993'
     *,access='direct',form='unformatted',recl=imax*jmax*4)
      open (51,file=path//'irwin-SA-ave-1.75x1.75deg-boxes-y1993' 
     *,access='direct',form='unformatted',recl=4*40*40)
      do 99 i=1,40
      do 98 j=1,40
      y(i,j)=-999.
 98   continue
 99   continue 
      nrec=0
      do 1 n=1,nobs1
      read(11,rec=n)x
      imn=1
      imx=25
      jmn=1
      jmx=25
      do 2 ii=1,40
      do 3 jj=1,40
      sum=0.
      cnt=0.
      do 4 i=imn,imx
      do 5 j=jmn,jmx
      if(x(i,j).lt.0.)go to 5
      cnt=cnt+1.
      sum=sum+x(i,j)
 5    continue
 4    continue
      if(cnt.eq.0.)go to 6
      xave(ii,jj)=sum/cnt
      jmn=jmn+25
      jmx=jmx+25
      go to 3
 6    xave(ii,jj)=-999.
 3    continue
      jmn=1
      jmx=25
      imn=imn+25
      imx=imx+25
 2    continue
      nrec=nrec+1
      write(51,rec=nrec)xave
 1    continue
      do 999 k=1,16
      nrec=nrec+1
      write(51,rec=nrec)y
 999  continue 
      do 10 n=1,nobs2
      read(12,rec=n)x
      imn=1
      imx=25
      jmn=1
      jmx=25
      do 20 ii=1,40
      do 30 jj=1,40
      sum=0.
      cnt=0.
      do 40 i=imn,imx
      do 50 j=jmn,jmx
      if(x(i,j).lt.0.)go to 50
      cnt=cnt+1.
      sum=sum+x(i,j)
 50   continue
 40   continue
      if(cnt.eq.0.)go to 60
      xave(ii,jj)=sum/cnt
      jmn=jmn+25
      jmx=jmx+25
      go to 30
 60   xave(ii,jj)=-999.
 30   continue
      jmn=1
      jmx=25
      imn=imn+25
      imx=imx+25
 20   continue
      nrec=nrec+1
      write(51,rec=nrec)xave
 10   continue
      write(6,200)nrec
 200  format(i10)
      stop
      end