subroutine decoder(ss,c0,nstandalone) ! 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*80 fmt character*20 datetime real*4 ccfred(NSMAX) real*4 red2(NSMAX) real*4 red3(NSMAX) logical ccfok(NSMAX) logical done(NSMAX) integer*1 i1SoftSymbols(207) complex c0(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 system_clock(iclock0,iclock_rate,iclock_max) !### nfreqs0=0 nfreqs1=0 ndecodes0=0 ndecodes1=0 call timer('decoder ',0) open(13,file='decoded.txt',status='unknown') ntrMinutes=ntrperiod/60 newdat=1 nsynced=0 ndecoded=0 nsps=0 if(ntrMinutes.eq.1) then nsps=6912 df3=1500.0/2048.0 fmt='(i4.4,i4,i5,f6.1,f8.0,i4,3x,a22)' else if(ntrMinutes.eq.2) then nsps=15360 df3=1500.0/2048.0 fmt='(i4.4,i4,i5,f6.1,f8.0,i4,3x,a22)' else if(ntrMinutes.eq.5) then nsps=40960 df3=1500.0/6144.0 fmt='(i4.4,i4,i5,f6.1,f8.1,i4,3x,a22)' else if(ntrMinutes.eq.10) then nsps=82944 df3=1500.0/12288.0 fmt='(i4.4,i4,i5,f6.1,f8.2,i4,3x,a22)' else if(ntrMinutes.eq.30) then nsps=252000 df3=1500.0/32768.0 fmt='(i4.4,i4,i5,f6.1,f8.2,i4,3x,a22)' endif if(nsps.eq.0) stop 'Error: bad TRperiod' !Better: return an error code### tstep=0.5*nsps/12000.0 !Half-symbol step (seconds) ! idf=ntol/df3 + 0.999 done=.false. ia=max(1,nint((nfa-1000)/df3)) ib=min(NSMAX,nint((nfb-1000)/df3)) lag1=-(2.5/tstep + 0.9999) lag2=5.0/tstep + 0.9999 call timer('sync9 ',0) call sync9(ss,nzhsym,lag1,lag2,ia,ib,ccfred,red2,red3,ipk) call timer('sync9 ',1) nsps8=nsps/8 df8=1500.0/nsps8 dblim=db(864.0/nsps8) - 26.2 do nqd=1,0,-1 limit=1000 ccflim=4.0 red2lim=1.6 schklim=2.2 if(ndepth.eq.2) then limit=10000 ccflim=3.5 endif if(ndepth.ge.3) then limit=100000 ccflim=2.5 endif ccfok=.false. if(nqd.eq.1) then limit=100000 ccfok(ia:ib)=.true. ! ccflim=2.0 ! red2lim=-20. ! schklim=1.0 nfa1=nfqso-ntol nfb1=nfqso+ntol ia=max(1,nint((nfa1-1000)/df3)) ib=min(NSMAX,nint((nfb1-1000)/df3)) ia1=ia ib1=ib else nfa1=nfa nfb1=nfb ia=max(1,nint((nfa1-1000)/df3)) ib=min(NSMAX,nint((nfb1-1000)/df3)) do i=ia,ib ccfok(i)=ccfred(i).gt.ccflim .and. red2(i).gt.red2lim enddo ccfok(ia1:ib1)=.false. endif nRxLog=0 fgood=0. do i=ia,ib f=(i-1)*df3 if(done(i) .or. (.not.ccfok(i)) .or. (ccfred(i).lt.ccflim-1.0)) cycle if(nqd.eq.1 .or. & (ccfred(i).ge.ccflim .and. abs(f-fgood).gt.10.0*df8)) then if(nqd.eq.0) nfreqs0=nfreqs0+1 if(nqd.eq.1) nfreqs1=nfreqs1+1 call timer('softsym ',0) fpk=1000.0 + df3*(i-1) call softsym(c0,npts8,nsps8,newdat,fpk,syncpk,snrdb,xdt,freq, & drift,schk,i1SoftSymbols) call timer('softsym ',1) if(schk.ge.schklim) then call timer('decode9 ',0) call decode9(i1SoftSymbols,limit,nlim,msg) call timer('decode9 ',1) sync=(syncpk+1)/4.0 if(sync.lt.0.0 .or. snrdb.lt.dblim-2.0) sync=0.0 nsync=sync if(nsync.gt.10) nsync=10 nsnr=nint(snrdb) ndrift=nint(drift/df3) write(38,3002) nutc,nqd,nsnr,i,freq,ccfred(i),red2(i), & red3(i),schk,nlim,msg 3002 format(i4.4,i2,i4,i5,f7.1,f5.1,f6.1,2f5.1,i8,1x,a22) if(msg.ne.' ') then if(nqd.eq.0) ndecodes0=ndecodes0+1 if(nqd.eq.1) ndecodes1=ndecodes1+1 write(*,fmt) nutc,nsync,nsnr,xdt,freq,ndrift,msg write(13,fmt) nutc,nsync,nsnr,xdt,freq,ndrift,msg ! write(14,1014) nutc,nsync,nsnr,xdt,freq,ndrift,ccfred(i),nlim,msg !1014 format(i4.4,i4,i5,f6.1,f8.0,i4,f9.1,i9,3x,a22) iaa=max(1,i-1) ibb=min(NSMAX,i+22) fgood=f nsynced=1 ndecoded=1 ccfok(iaa:ibb)=.false. done(iaa:ibb)=.true. call flush(6) endif else write(38,3002) nutc,nqd,-99,i,freq,ccfred(i),red2(i),red3(i), & schk,0 endif endif enddo call flush(6) if(nagain.ne.0) exit enddo write(*,1010) nsynced,ndecoded 1010 format('',2i4) call flush(6) close(13) ! call flush(14) call timer('decoder ',1) if(nstandalone.eq.0) call timer('decoder ',101) call system_clock(iclock,iclock_rate,iclock_max) write(39,3001) nutc,nfreqs1,nfreqs0,ndecodes1,ndecodes0+ndecodes1, & float(iclock-iclock0)/iclock_rate 3001 format(5i8,f10.3) call flush(38) call flush(39) return end subroutine decoder