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https://github.com/saitohirga/WSJT-X.git
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232 lines
6.5 KiB
Fortran
232 lines
6.5 KiB
Fortran
module wideband_sync
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type candidate
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real :: snr !Relative S/N of sync detection
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real :: f !Freq of sync tone, 0 to 96000 Hz
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real :: xdt !DT of matching sync pattern, -1.0 to +4.0 s
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integer :: ipol !Polarization angle, 1 to 4 ==> 0, 45, 90, 135 deg
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integer :: iflip !Sync type: JT65 = +/- 1, Q65 = 0
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end type candidate
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type sync_dat
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real :: ccfmax
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real :: xdt
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integer :: ipol
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integer :: iflip
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logical :: birdie
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end type sync_dat
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parameter (NFFT=32768)
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parameter (MAX_CANDIDATES=50)
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type(sync_dat) :: sync(NFFT)
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integer nkhz_center
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contains
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subroutine get_candidates(ss,savg,nfa,nfb,nts_jt65,nts_q65,cand,ncand)
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! Search symbol spectra ss() over frequency range nfa to nfb (in kHz) for
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! JT65 and Q65 sync patterns. The nts_* variables are the submode tone
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! spacings: 1 2 4 8 16 for A B C D E. Birdies are detected and
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! excised. Candidates are returned in the structure array cand().
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parameter (MAX_PEAKS=300)
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real ss(4,322,NFFT),savg(4,NFFT)
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real pavg(-20:20)
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integer indx(NFFT)
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logical skip
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type(candidate) :: cand(MAX_CANDIDATES)
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do j=322,1,-1 !Find end of data in ss()
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if(sum(ss(1,j,1:NFFT)).gt.0.0) exit
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enddo
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jz=j
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call wb_sync(ss,savg,jz,nfa,nfb)
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tstep=2048.0/11025.0 !0.185760 s: 0.5*tsym_jt65, 0.3096*tsym_q65
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df3=96000.0/NFFT
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ia=nint(1000*nfa/df3) + 1
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ib=nint(1000*nfb/df3) + 1
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iz=ib-ia+1
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call indexx(sync(ia:ib)%ccfmax,iz,indx) !Sort by relative snr
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k=0
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do i=1,MAX_PEAKS
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n=indx(iz+1-i) + ia - 1
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f0=0.001*(n-1)*df3
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snr1=sync(n)%ccfmax
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! print*,'=A',f0,snr1
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if(snr1.lt.4.5) exit
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flip=sync(n)%iflip
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if(flip.ne.0.0 .and. nts_jt65.eq.0) cycle
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if(flip.eq.0.0 .and. nts_q65.eq.0) cycle
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if(sync(n)%birdie) cycle
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! Test for signal outside of TxT range and set bw for this signal type
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j1=(sync(n)%xdt + 1.0)/tstep - 1.0
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j2=(sync(n)%xdt + 52.0)/tstep + 1.0
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if(flip.ne.0) j2=(sync(n)%xdt + 47.811)/tstep + 1.0
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ipol=sync(n)%ipol
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pavg=0.
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do j=1,j1
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pavg=pavg + ss(ipol,j,n-20:n+20)
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enddo
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do j=j2,jz
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pavg=pavg + ss(ipol,j,n-20:n+20)
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enddo
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jsum=j1 + (jz-j2+1)
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pmax=maxval(pavg(-2:2)) !### Why not just pavg(0) ?
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base=(sum(pavg)-pmax)/jsum
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pmax=pmax/base
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if(pmax.gt.5.0) cycle
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skip=.false.
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do m=1,k !Skip false syncs within signal bw
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diffhz=1000.0*(f0-cand(m)%f)
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bw=nts_q65*110.0
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if(cand(m)%iflip.ne.0) bw=nts_jt65*178.0
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if(diffhz.gt.-20.0 .and. diffhz.lt.bw+20.0) skip=.true.
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! write(*,3301) i,k,m,f0,cand(m)%f,diffhz,snr1,skip
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!3301 format('=',3i5,f10.1,3f10.3,L3)
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enddo
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if(skip) cycle
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k=k+1
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cand(k)%snr=snr1
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cand(k)%f=f0
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cand(k)%xdt=sync(n)%xdt
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cand(k)%ipol=sync(n)%ipol
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cand(k)%iflip=nint(flip)
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if(k.ge.MAX_CANDIDATES) exit
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enddo
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ncand=k
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return
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end subroutine get_candidates
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subroutine wb_sync(ss,savg,jz,nfa,nfb)
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! Compute "orange sync curve" using the Q65 sync pattern
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parameter (NFFT=32768)
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parameter (LAGMAX=30)
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real ss(4,322,NFFT)
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real savg(4,NFFT)
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real savg_med(4)
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logical first
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integer isync(22)
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integer jsync0(63),jsync1(63)
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! Q65 sync symbols
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data isync/1,9,12,13,15,22,23,26,27,33,35,38,46,50,55,60,62,66,69,74,76,85/
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data jsync0/ &
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1, 4, 5, 9, 10, 11, 12, 13, 14, 16, 18, 22, 24, 25, 28, 32, &
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33, 34, 37, 38, 39, 40, 42, 43, 45, 46, 47, 48, 52, 53, 55, 57, &
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59, 60, 63, 64, 66, 68, 70, 73, 80, 81, 89, 90, 92, 95, 97, 98, &
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100,102,104,107,108,111,114,119,120,121,122,123,124,125,126/
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data jsync1/ &
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2, 3, 6, 7, 8, 15, 17, 19, 20, 21, 23, 26, 27, 29, 30, 31, &
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35, 36, 41, 44, 49, 50, 51, 54, 56, 58, 61, 62, 65, 67, 69, 71, &
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72, 74, 75, 76, 77, 78, 79, 82, 83, 84, 85, 86, 87, 88, 91, 93, &
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94, 96, 99,101,103,105,106,109,110,112,113,115,116,117,118/
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data first/.true./
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save first,isync,jsync0,jsync1
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tstep=2048.0/11025.0 !0.185760 s: 0.5*tsym_jt65, 0.3096*tsym_q65
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if(first) then
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fac=0.6/tstep
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do i=1,22 !Expand the Q65 sync stride
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isync(i)=nint((isync(i)-1)*fac) + 1
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enddo
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do i=1,63
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jsync0(i)=2*(jsync0(i)-1) + 1
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jsync1(i)=2*(jsync1(i)-1) + 1
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enddo
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first=.false.
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endif
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df3=96000.0/NFFT
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ia=nint(1000*nfa/df3) + 1 !Flat frequency range for WSE converters
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ib=nint(1000*nfb/df3) + 1
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do i=1,4
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call pctile(savg(i,ia:ib),ib-ia+1,50,savg_med(i))
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enddo
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! do i=ia,ib
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! write(14,3014) 0.001*(i-1)*df3,savg(1:4,i)
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!3014 format(5f10.3)
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! enddo
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lagbest=0
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ipolbest=1
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flip=0.
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do i=ia,ib
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ccfmax=0.
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do ipol=1,4
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do lag=0,LAGMAX
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ccf=0.
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do j=1,22
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k=isync(j) + lag
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ccf=ccf + ss(ipol,k,i+1) + ss(ipol,k+1,i+1) + ss(ipol,k+2,i+1)
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enddo
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ccf=ccf - savg(ipol,i+1)*3*22/float(jz)
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if(ccf.gt.ccfmax) then
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ipolbest=ipol
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lagbest=lag
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ccfmax=ccf
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flip=0.
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endif
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ccf=0.
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do j=1,63
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k=jsync0(j) + lag
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ccf=ccf + ss(ipol,k,i+1) + ss(ipol,k+1,i+1)
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enddo
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ccf=ccf - savg(ipol,i+1)*2*63/float(jz)
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if(ccf.gt.ccfmax) then
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ipolbest=ipol
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lagbest=lag
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ccfmax=ccf
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flip=1.0
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endif
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ccf=0.
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do j=1,63
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k=jsync1(j) + lag
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ccf=ccf + ss(ipol,k,i+1) + ss(ipol,k+1,i+1)
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enddo
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ccf=ccf - savg(ipol,i+1)*2*63/float(jz)
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if(ccf.gt.ccfmax) then
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ipolbest=ipol
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lagbest=lag
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ccfmax=ccf
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flip=-1.0
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endif
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enddo ! lag
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enddo !ipol
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sync(i)%ccfmax=ccfmax
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sync(i)%xdt=lagbest*tstep-1.0
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sync(i)%ipol=ipolbest
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sync(i)%iflip=flip
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sync(i)%birdie=.false.
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if(ccfmax/(savg(ipolbest,i)/savg_med(ipolbest)).lt.3.0) sync(i)%birdie=.true.
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enddo ! i (frequency bin)
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! do i=ia,ib
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! write(15,3015) 0.001*(i-1)*df3,sync(i)%ccfmax,sync(i)%xdt,sync(i)%ipol, &
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! sync(i)%iflip,sync(i)%birdie
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!3015 format(3f10.3,2i6,L5)
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! enddo
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call pctile(sync(ia:ib)%ccfmax,ib-ia+1,50,base)
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sync(ia:ib)%ccfmax=sync(ia:ib)%ccfmax/base
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! print*,base
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return
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end subroutine wb_sync
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end module wideband_sync
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