subroutine decoder(ss,c0) ! Decoder for JT9. parameter (NMAX=1800*12000) !Total sample intervals per 30 minutes parameter (NDMAX=1800*1500) !Sample intervals at 1500 Hz rate parameter (NSMAX=22000) !Max length of saved spectra real ss(184,NSMAX) character*22 msg character*33 line character*80 fmt,fmt14 character*20 datetime real*4 ccfred(NSMAX) integer*1 i1SoftSymbols(207) integer*2 id2 integer ii(1) complex c0(NDMAX) complex c1(NDMAX) common/npar/nutc,ndiskdat,ntrperiod,nfqso,newdat,npts8,nfa,nfb,ntol, & kin,nzhsym,nsave,nagain,ndepth,nrxlog,nfsample,datetime common/tracer/limtrace,lu save call timer('decoder ',0) ntrMinutes=ntrperiod/60 newdat=1 nsynced=0 ndecoded=0 limit=200 if(ndepth.ge.2) limit=2000 if(ndepth.ge.3) limit=20000 nsps=0 if(ntrMinutes.eq.1) then nsps=6912 df3=1500.0/2048.0 fmt='(i4.4,i4,i5,f6.1,f8.0,f6.1,3x,a22)' fmt14='(i4.4,i4,i5,f6.1,f8.0,f6.1,i3,i8,3x,a22)' else if(ntrMinutes.eq.2) then nsps=15360 df3=1500.0/2048.0 fmt='(i4.4,i4,i5,f6.1,f8.1,f6.2,3x,a22)' fmt14='(i4.4,i4,i5,f6.1,f8.1,f6.2,i3,i8,3x,a22)' else if(ntrMinutes.eq.5) then nsps=40960 df3=1500.0/6144.0 fmt='(i4.4,i4,i5,f6.1,f8.1,f6.2,3x,a22)' fmt14='(i4.4,i4,i5,f6.1,f8.1,f6.2,i3,i8,3x,a22)' else if(ntrMinutes.eq.10) then nsps=82944 df3=1500.0/12288.0 fmt='(i4.4,i4,i5,f6.1,f8.2,f6.2,3x,a22)' fmt14='(i4.4,i4,i5,f6.1,f8.2,f6.2,i3,i8,3x,a22)' else if(ntrMinutes.eq.30) then nsps=252000 df3=1500.0/32768.0 fmt='(i4.4,i4,i5,f6.1,f8.2,f6.2,3x,a22)' fmt14='(i4.4,i4,i5,f6.1,f8.2,f6.2,i3,i8,3x,a22)' endif if(nsps.eq.0) stop 'Error: bad TRperiod' !Better: return an error code### kstep=nsps/2 tstep=kstep/12000.0 call timer('sync9 ',0) call sync9(ss,nzhsym,tstep,df3,ntol,nfqso,ccfred,ia,ib,ipk) !Compute ccfred call timer('sync9 ',1) ! open(13,file='decoded.txt',status='unknown') ! rewind 13 if(iand(nRxLog,2).ne.0) rewind 14 if(iand(nRxLog,1).ne.0) then ! Write date and time to lu 14 endif nRxLog=0 fgood=0. nsps8=nsps/8 df8=1500.0/nsps8 sbest=0. 10 ii=maxloc(ccfred(ia:ib)) i=ii(1) + ia - 1 f=(i-1)*df3 if((i.eq.ipk .or. ccfred(i).ge.3.0) .and. abs(f-fgood).gt.10.0*df8) then ! call timer('spec9 ',0) ! call spec9(c0,npts8,nsps,f,fpk,xdt,snr,i1SoftSymbols) ! call timer('spec9 ',1) call timer('decode9a',0) fpk=1000.0 + df3*(i-1) c1(1:npts8)=conjg(c0(1:npts8)) call decode9a(c1,npts8,nsps8,fpk,syncpk,snrdb,xdt,freq,drift,i1SoftSymbols) call timer('decode9a',1) call timer('decode9 ',0) call decode9(i1SoftSymbols,limit,nlim,msg) call timer('decode9 ',1) sync=(syncpk-1.0)/2.0 if(sync.lt.0.0) sync=0.0 nsync=sync if(nsync.gt.10) nsync=10 nsnr=nint(snrdb) if(sync.gt.sbest .and. fgood.eq.0.0) then sbest=sync write(line,fmt) nutc,nsync,nsnr,xdt,freq,drift if(nsync.gt.0) nsynced=1 endif if(msg.ne.' ') then write(*,fmt) nutc,nsync,nsnr,xdt,freq,drift,msg write(14,fmt14) nutc,nsync,nsnr,xdt,freq,drift,ntrMinutes,nlim,msg fgood=f nsynced=1 ndecoded=1 ccfred(max(ia,i-3):min(ib,i+11))=0. endif endif ccfred(i)=0. if(maxval(ccfred(ia:ib)).gt.3.0) go to 10 if(fgood.eq.0.0) then write(*,1020) line write(14,1020) line 1020 format(a33) endif write(*,1010) nsynced,ndecoded 1010 format('',2i4) flush(6) call flush(6) call flush(14) call timer('decoder ',1) if(nstandalone.eq.0) call timer('decoder ',101) return end subroutine decoder