Initial Commit

2018-02-08 21:28:33 -05:00
commit 678c1d3966
14352 changed files with 3176737 additions and 0 deletions
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+subroutine ccf65(ss,nhsym,ssmax,sync1,dt1,flipk,syncshort,snr2,dt2)
+
+  parameter (NFFT=512,NH=NFFT/2)
+  real ss(322)                     !Input: half-symbol normalized powers
+  real s(NFFT)                     !CCF = ss*pr
+  complex cs(0:NH)                 !Complex FT of s
+  real s2(NFFT)                    !CCF = ss*pr2
+  complex cs2(0:NH)                !Complex FT of s2
+  real pr(NFFT)                    !JT65 pseudo-random sync pattern
+  complex cpr(0:NH)                !Complex FT of pr
+  real pr2(NFFT)                   !JT65 shorthand pattern
+  complex cpr2(0:NH)               !Complex FT of pr2
+  real tmp1(322)
+  real ccf(-11:54)
+  logical first
+  integer npr(126)
+  data first/.true./
+  equivalence (s,cs),(pr,cpr),(s2,cs2),(pr2,cpr2)
+  save
+
+! The JT65 pseudo-random sync pattern:
+  data npr/                                        &
+      1,0,0,1,1,0,0,0,1,1,1,1,1,1,0,1,0,1,0,0,     &
+      0,1,0,1,1,0,0,1,0,0,0,1,1,1,0,0,1,1,1,1,     &
+      0,1,1,0,1,1,1,1,0,0,0,1,1,0,1,0,1,0,1,1,     &
+      0,0,1,1,0,1,0,1,0,1,0,0,1,0,0,0,0,0,0,1,     &
+      1,0,0,0,0,0,0,0,1,1,0,1,0,0,1,0,1,1,0,1,     &
+      0,1,0,1,0,0,1,1,0,0,1,0,0,1,0,0,0,0,1,1,     &
+      1,1,1,1,1,1/
+
+  if(first) then
+! Initialize pr, pr2; compute cpr, cpr2.
+     fac=1.0/NFFT
+     do i=1,NFFT
+        pr(i)=0.
+        pr2(i)=0.
+        k=2*mod((i-1)/8,2)-1
+        if(i.le.NH) pr2(i)=fac*k
+     enddo
+     do i=1,126
+        j=2*i
+        pr(j)=fac*(2*npr(i)-1)
+! Not sure why, but it works significantly better without the following line:
+!        pr(j-1)=pr(j)
+     enddo
+     call four2a(cpr,NFFT,1,-1,0)
+     call four2a(cpr2,NFFT,1,-1,0)
+     first=.false.
+  endif
+
+! Look for JT65 sync pattern and shorthand square-wave pattern.
+  ccfbest=0.
+  ccfbest2=0.
+  do i=1,nhsym-1
+     s(i)=min(ssmax,ss(i)+ss(i+1))
+!     s(i)=ss(i)+ss(i+1)
+  enddo
+
+  call pctile(s,nhsym-1,50,base)
+  s(1:nhsym-1)=s(1:nhsym-1)-base
+  s(nhsym:NFFT)=0.
+  call four2a(cs,NFFT,1,-1,0)               !Real-to-complex FFT
+  do i=0,NH
+!     cs2(i)=cs(i)*conjg(cpr2(i))            !Mult by complex FFT of pr2
+     cs(i)=cs(i)*conjg(cpr(i))              !Mult by complex FFT of pr
+  enddo
+  call four2a(cs,NFFT,1,1,-1)               !Complex-to-real inv-FFT
+!  call four2a(cs2,NFFT,1,1,-1)              !Complex-to-real inv-FFT
+
+  do lag=-11,54                             !Check for best JT65 sync
+     j=lag
+     if(j.lt.1) j=j+NFFT
+     ccf(lag)=s(j)
+!     if(abs(ccf(lag)).gt.ccfbest) then
+     if(ccf(lag).gt.ccfbest) then           !No inverted sync for use at HF
+!        ccfbest=abs(ccf(lag))
+        ccfbest=ccf(lag)
+        lagpk=lag
+        flipk=1.0
+!        if(ccf(lag).lt.0.0) flipk=-1.0
+     endif
+  enddo
+
+!  do lag=-11,54                             !Check for best shorthand
+!     ccf2=s2(lag+28)
+!     if(ccf2.gt.ccfbest2) then
+!        ccfbest2=ccf2
+!        lagpk2=lag
+!     endif
+!  enddo
+
+! Find rms level on baseline of "ccfblue", for normalization.
+  sum=0.
+  do lag=-11,54
+     if(abs(lag-lagpk).gt.1) sum=sum + ccf(lag)
+  enddo
+  base=sum/50.0
+  sq=0.
+  do lag=-11,54
+     if(abs(lag-lagpk).gt.1) sq=sq + (ccf(lag)-base)**2
+  enddo
+  rms=sqrt(sq/49.0)
+  sync1=ccfbest/rms - 4.0
+  dt1=lagpk*(2048.0/11025.0) - 2.5
+
+! Find base level for normalizing snr2.
+  do i=1,nhsym
+     tmp1(i)=ss(i)
+  enddo
+  call pctile(tmp1,nhsym,40,base)
+  snr2=0.398107*ccfbest2/base                !### empirical
+  syncshort=0.5*ccfbest2/rms - 4.0           !### better normalizer than rms?
+!  dt2=(2.5 + lagpk2*(2048.0/11025.0))
+  dt2=0.
+
+  return
+end subroutine ccf65