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Improve sync_q65() for larger values of FTol.

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Joe Taylor 2020-11-03 11:31:21 -05:00
parent 2c51c97b14
commit a01ebab363
1 changed files with 22 additions and 8 deletions
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30
lib/sync_q65.f90
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@ -15,10 +15,10 @@ subroutine sync_q65(iwave,nmax,mode65,nsps,nfqso,ntol,xdt,f0,snr1,width)
parameter (NSTEP=8) !Step size nsps/NSTEP
integer*2 iwave(0:nmax-1) !Raw data
integer isync(22) !Indices of sync symbols
integer ijpk(2) !Indices i and j at peak of ccf
real, allocatable :: s1(:,:) !Symbol spectra, quarter-symbol steps
real, allocatable :: ccf(:,:) !CCF(freq,lag)
real, allocatable :: ccf1(:) !CCF(freq) at best lag
real sync(85) !sync vector
real ccf(-64:64,-53:214) !CCF(freq,time)
complex, allocatable :: c0(:) !Complex spectrum of symbol
data isync/1,9,12,13,15,22,23,26,27,33,35,38,46,50,55,60,62,66,69,74,76,85/
data sync(1)/99.0/
@ -31,9 +31,12 @@ subroutine sync_q65(iwave,nmax,mode65,nsps,nfqso,ntol,xdt,f0,snr1,width)
txt=85.0*nsps/12000.0
jz=(txt+1.0)*12000.0/istep !Number of quarter-symbol steps
if(nsps.ge.6912) jz=(txt+2.0)*12000.0/istep !For TR 60 s and higher
ia=ntol/df
allocate(s1(iz,jz))
allocate(c0(0:nfft-1))
allocate(ccf(-ia:ia,-53:214))
allocate(ccf1(-ia:ia))
if(sync(1).eq.99.0) then !Generate the sync vector
sync=-22.0/63.0 !Sync tone OFF
@ -74,7 +77,7 @@ subroutine sync_q65(iwave,nmax,mode65,nsps,nfqso,ntol,xdt,f0,snr1,width)
enddo
dtstep=nsps/(NSTEP*12000.0) !Step size in seconds
ia=min(64,nint(ntol/df))
ia=ntol/df
lag1=-1.0/dtstep
lag2=1.0/dtstep + 0.9999
j0=0.5/dtstep
@ -94,9 +97,19 @@ subroutine sync_q65(iwave,nmax,mode65,nsps,nfqso,ntol,xdt,f0,snr1,width)
enddo
enddo
ijpk=maxloc(ccf)
ipk=ijpk(1)-65
jpk=ijpk(2)-54
ic=ntol/df
ccfmax=0.
ipk=0
jpk=0
do i=-ic,ic
do j=lag1,lag2
if(ccf(i,j).gt.ccfmax) then
ipk=i
jpk=j
ccfmax=ccf(i,j)
endif
enddo
enddo
f0=nfqso + ipk*df
xdt=jpk*dtstep
@ -123,9 +136,10 @@ subroutine sync_q65(iwave,nmax,mode65,nsps,nfqso,ntol,xdt,f0,snr1,width)
! enddo
! flush(56)
acf0=dot_product(ccf(-ia:ia,jpk),ccf(-ia:ia,jpk))
ccf1=ccf(-ia:ia,jpk)
acf0=dot_product(ccf1,ccf1)
do i=1,ia
acf=dot_product(ccf(-ia:ia,jpk),ccf(-ia+i:ia+i,jpk))
acf=dot_product(ccf1,cshift(ccf1,i))
if(acf.le.0.5*acf0) exit
enddo
width=i*1.414*df