subroutine jtmsk_decode(id2,narg,line) ! Calls the experimental decoder for JTMSK 72ms ldpc messages parameter (NMAX=30*12000) parameter (NFFTMAX=512*1024) parameter (NSPM=864) !Samples per JTMSK long message integer*2 id2(0:NMAX) !Raw i*2 data, up to T/R = 30 s integer hist(0:32868) real d(0:NMAX) !Raw r*4 data real ty(NMAX/512) !Ping times real yellow(NMAX/512) complex c(NFFTMAX) !Complex (analytic) data complex cdat(24000) !Short segments, up to 2 s complex cdat2(24000) integer narg(0:14) !Arguments passed from calling pgm character*22 msg,msg0 !Decoded message character*80 line(100) !Decodes passed back to caller equivalence (hist,d) ! Parameters from GUI are in narg(): nutc=narg(0) !UTC npts=min(narg(1),NMAX) !Number of samples in id2 (12000 Hz) newdat=narg(3) !1==> new data, compute symbol spectra minsync=narg(4) !Lower sync limit npick=narg(5) t0=0.001*narg(6) t1=0.001*narg(7) maxlines=narg(8) !Max # of decodes to return to caller nmode=narg(9) nrxfreq=narg(10) !Target Rx audio frequency (Hz) ntol=narg(11) !Search range, +/- ntol (Hz) nhashcalls=narg(12) naggressive=narg(14) nsnr0=-99 nline=0 line(1:100)(1:1)=char(0) msg0=' ' msg=msg0 hist=0 do i=0,npts-1 n=abs(id2(i)) hist(n)=hist(n)+1 enddo ns=0 do n=0,32768 ns=ns+hist(n) if(ns.gt.npts/2) exit enddo fac=1.0/(1.5*n) d(0:npts-1)=fac*id2(0:npts-1) ! rms=sqrt(dot_product(d(0:npts-1),d(0:npts-1))/npts) !### Would it be better to set median rms to 1.0 ? ! d(0:npts-1)=d(0:npts-1)/rms !Normalize so that rms=1.0 call mskdt(d,npts,ty,yellow,nyel) ! do i=1,nyel ! print*,i,ty(i),yellow(i) ! enddo nyel=min(nyel,5) n=log(float(npts))/log(2.0) + 1.0 nfft=min(2**n,1024*1024) call analytic(d,npts,nfft,c) !Convert to analytic signal and filter nafter=NSPM ! Process ping list (sorted by S/N) from top down. ! do n=1,nyel do n=1,nyel ia=ty(n)*12000.0 - NSPM/2 if(ia.lt.1) ia=1 ib=ia + 2*nafter-1 if(ib.gt.NFFTMAX) ib=NFFTMAX iz=ib-ia+1 cdat2(1:iz)=c(ia:ib) !Select nlen complex samples write(*,*) ty(1),ia,ib,iz ja=ia/NSPM + 1 jb=ib/NSPM t0=ia/12000.0 ! do itry=1,21 do itry=1,1 idf1=(itry/2) * 50 if(mod(itry,2).eq.1) idf1=-idf1 if(abs(idf1).gt.ntol) exit fpk=idf1 + nrxfreq call tweak1(cdat2,iz,1500.0-fpk,cdat) call syncmsk144(cdat,iz,jpk,ipk,idf,rmax,snr,metric,msg,freq) if(metric.eq.-9999) cycle !No output if no significant sync if(msg(1:1).eq.' ') call jtmsk_short(cdat,iz,narg,tbest,idfpk,msg) if(msg(1:1).eq.'<' .and. naggressive.eq.0 .and. & narg(13)/8.ne.narg(12)) msg=' ' if(msg(1:1).ne.' ') then ! if(msg.ne.msg0) then nline=nline+1 nsnr0=-99 ! endif t0=(ia+jpk)/12000.0 y=10.0**(0.1*(yellow(n)-1.5)) nsnr=max(-5,nint(db(y))) ! if(nsnr.gt.nsnr0 .and. nline.gt.0) then write(line(nline),1020) nutc,nsnr,t0,nint(freq),msg 1020 format(i6.6,i4,f5.1,i5,' & ',a22) nsnr0=nsnr ! go to 900 ! endif msg0=msg ! if(nline.ge.maxlines) go to 900 endif enddo ! print*,'c',nutc,n,nint(yellow(n)-4.0),freq,freq2 enddo 900 continue ! print*,'d',nutc,n,nint(yellow(n)-4.0),freq,freq2 if(line(1)(1:6).eq.' ') line(1)(1:1)=char(0) return end subroutine jtmsk_decode