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876668f7cb
Quick-decode searches over ipol, DT, and nflip. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/map65@406 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
46 lines
1.1 KiB
Fortran
46 lines
1.1 KiB
Fortran
subroutine ccf2(ss,nz,nflip,ccfbest,lagpk)
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! parameter (LAGMAX=20)
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parameter (LAGMAX=100)
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real ss(nz)
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real ccf(-LAGMAX:LAGMAX)
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integer npr(126)
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C The JT65 pseudo-random sync pattern:
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data npr/
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+ 1,0,0,1,1,0,0,0,1,1,1,1,1,1,0,1,0,1,0,0,
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+ 0,1,0,1,1,0,0,1,0,0,0,1,1,1,0,0,1,1,1,1,
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+ 0,1,1,0,1,1,1,1,0,0,0,1,1,0,1,0,1,0,1,1,
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+ 0,0,1,1,0,1,0,1,0,1,0,0,1,0,0,0,0,0,0,1,
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+ 1,0,0,0,0,0,0,0,1,1,0,1,0,0,1,0,1,1,0,1,
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+ 0,1,0,1,0,0,1,1,0,0,1,0,0,1,0,0,0,0,1,1,
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+ 1,1,1,1,1,1/
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save
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ccfbest=0.
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lag1=-LAGMAX
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lag2=LAGMAX
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do lag=lag1,lag2
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s0=0.
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s1=0.
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do i=1,126
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j=2*(8*i + 43) + lag
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if(j.ge.1 .and. j.le.nz-8) then
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x=ss(j)+ss(j+8)
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if(npr(i).eq.0) then
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s0=s0 + x
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else
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s1=s1 + x
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endif
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endif
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enddo
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ccf(lag)=nflip*(s1-s0)
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if(ccf(lag).gt.ccfbest) then
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ccfbest=ccf(lag)
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lagpk=lag
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endif
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enddo
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return
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end
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