mirror of https://github.com/saitohirga/WSJT-X.git
148 lines
3.3 KiB
Fortran
148 lines
3.3 KiB
Fortran
subroutine qra64a(dd,nf1,nf2,nfqso,ntol,mycall_12,sync,nsnr,dtx,nfreq, &
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decoded,nft)
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use packjt
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parameter (NFFT=2*6912,NH=NFFT/2,NZ=5760)
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character decoded*22,mycall_12*12,mycall*6
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character*1 mark(0:5),zplot(0:63)
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logical ltext
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integer icos7(0:6)
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integer ipk(1)
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integer jpk(1)
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integer dat4(12)
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real dd(60*12000)
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real s(NZ)
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real savg(NZ)
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real blue(0:25)
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real red0(NZ)
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real red(NZ)
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real x(NFFT)
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complex cx(0:NH)
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equivalence (x,cx)
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data icos7/2,5,6,0,4,1,3/ !Costas 7x7 pattern
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data mark/' ','.','-','+','X','$'/
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common/qra64com/ss(NZ,194),s3(0:63,1:63),ccf(NZ,0:25)
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save
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decoded=' '
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nft=99
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nsnr=-30
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nsps=6912
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istep=nsps/2
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nsteps=52*12000/istep - 2
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ia=1-istep
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savg=0.
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df=12000.0/NFFT
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do j=1,nsteps
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ia=ia+istep
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ib=ia+nsps-1
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x(1:nsps)=1.2e-4*dd(ia:ib)
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x(nsps+1:)=0.0
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call four2a(x,nfft,1,-1,0) !r2c FFT
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do i=1,NZ
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s(i)=real(cx(i))**2 + aimag(cx(i))**2
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enddo
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ss(1:NZ,j)=s
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savg=savg+s
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enddo
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savg=savg/nsteps
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call pctile(savg,NZ,45,base)
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savg=savg/base - 1.0
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ss=ss/base
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fa=max(nf1,nfqso-ntol)
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fb=min(nf2,nfqso+ntol)
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ia=nint(fa/df)
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ib=nint(fb/df)
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red0=0.
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fac=1.0/sqrt(21.0)
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sync=0.
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do if0=ia,ib
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red0(if0)=0.
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do j=0,25
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t=-3.0
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do n=0,6
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i=if0 + 2*icos7(n)
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t=t + ss(i,1+2*n+j) + ss(i,1+2*n+j+78) + ss(i,1+2*n+j+154)
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enddo
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ccf(if0,j)=fac*t
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if(ccf(if0,j).gt.red0(if0)) then
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red0(if0)=ccf(if0,j)
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if(red0(if0).gt.sync) then
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sync=red0(if0)
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f0=if0*df
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dtx=j*istep/12000.0 - 1.0
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i0=if0
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j0=j
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endif
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endif
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enddo
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enddo
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red(ia:ib)=0.
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rewind 73
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do i=ia+3,ib-3
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r1=red0(i)
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red0(i)=0.
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r0=maxval(red0(i-3:i+3))
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red0(i)=r1
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red(i)=max(0.0,r1-r0)
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write(73,3001) i*df,red(i),red0(i),r0
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3001 format(4f12.3)
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enddo
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flush(73)
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write(17) ia,ib,red(ia:ib)
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close(17)
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if0=nint(f0/df)
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nfreq=nint(f0)
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blue(0:25)=ccf(if0,0:25)
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jpk=maxloc(blue)
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xpk=jpk(1) + 1.0
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call slope(blue,26,xpk)
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! Insist on at least 10 correct hard decisions in the 21 Costas bins.
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nhard=0
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do n=0,6
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ipk=maxloc(ss(i0:i0+63,1+j0+2*n)) - 1
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i=abs(ipk(1)-2*icos7(n))
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if(i.le.1) nhard=nhard+1
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ipk=maxloc(ss(i0:i0+63,1+j0+2*n+78)) - 1
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i=abs(ipk(1)-2*icos7(n))
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if(i.le.1) nhard=nhard+1
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ipk=maxloc(ss(i0:i0+63,1+j0+2*n+154)) - 1
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i=abs(ipk(1)-2*icos7(n))
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if(i.le.1) nhard=nhard+1
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enddo
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! print*,'a',nhard,nhard,nhard
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if(nhard.lt.6) go to 900
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do i=0,63
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k=i0 + 2*i
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jj=j0+13
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do j=1,63
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jj=jj+2
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s3(i,j)=ss(k,jj)
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if(j.eq.32) jj=jj+14 !Skip over the middle Costas array
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enddo
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enddo
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if(sync.gt.1.0) nsnr=nint(10.0*log10(sync) - 38.0)
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! if(sync.lt.12.8) go to 900 !### Temporary ###
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mycall=mycall_12(1:6) !### May need fixing ###
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call packcall(mycall,nmycall,ltext)
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call qra64_dec(s3,nmycall,dat4,irc) !Attempt decoding
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if(irc.ge.0) then
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call unpackmsg(dat4,decoded) !Unpack the user message
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call fmtmsg(decoded,iz)
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nft=100 + irc
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endif
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900 return
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end subroutine qra64a
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