mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-15 16:42:12 -05:00
61 lines
1.7 KiB
Fortran
61 lines
1.7 KiB
Fortran
|
subroutine sync4(dat,jz,mode4,minw)
|
||
|
|
|
||
|
|
! Synchronizes JT4 data, finding the best-fit DT and DF.
|
||
|
|
|
||
|
|
use jt4
|
||
|
|
parameter (NFFTMAX=2520) !Max length of FFTs
|
||
|
|
parameter (NHMAX=NFFTMAX/2) !Max length of power spectra
|
||
|
|
parameter (NSMAX=525) !Max number of half-symbol steps
|
||
|
|
real dat(jz)
|
||
|
|
real psavg(NHMAX) !Average spectrum of whole record
|
||
|
|
real s2(NHMAX,NSMAX) !2d spectrum, stepped by half-symbols
|
||
|
|
real ccfblue(65) !CCF with pseudorandom sequence
|
||
|
|
real tmp(1260)
|
||
|
|
save
|
||
|
|
|
||
|
|
! Do FFTs of twice symbol length, stepped by half symbols. Note that
|
||
|
|
! we have already downsampled the data by factor of 2.
|
||
|
|
|
||
|
|
nsym=207
|
||
|
|
nfft=2520
|
||
|
|
nh=nfft/2
|
||
|
|
nq=nfft/4
|
||
|
|
nsteps=jz/nq - 1
|
||
|
|
df=0.5*11025.0/nfft
|
||
|
|
psavg(1:nh)=0.
|
||
|
|
|
||
|
|
call timer('ps4 ',0)
|
||
|
|
do j=1,nsteps !Compute spectrum for each step, get average
|
||
|
|
k=(j-1)*nq + 1
|
||
|
|
call ps4(dat(k),nfft,s2(1,j))
|
||
|
|
psavg(1:nh)=psavg(1:nh) + s2(1:nh,j)
|
||
|
|
enddo
|
||
|
|
call timer('ps4 ',1)
|
||
|
|
|
||
|
|
call timer('flat1a ',0)
|
||
|
|
nsmo=min(10*mode4,150)
|
||
|
|
call flat1a(psavg,nsmo,s2,nh,nsteps,NHMAX,NSMAX) !Flatten spectra
|
||
|
|
call timer('flat1a ',1)
|
||
|
|
|
||
|
|
call timer('smo ',0)
|
||
|
|
if(mode4.ge.9) call smo(psavg,nh,tmp,mode4/4)
|
||
|
|
call timer('smo ',1)
|
||
|
|
|
||
|
|
ia=600.0/df
|
||
|
|
ib=1600.0/df
|
||
|
|
|
||
|
|
! ichmax=1.0+log(float(mode4))/log(2.0)
|
||
|
|
do ich=minw+1,7 !Find best width
|
||
|
|
kz=nch(ich)/2
|
||
|
|
! Set istep>1 for wide submodes?
|
||
|
|
do i=ia+kz,ib-kz !Find best frequency channel for CCF
|
||
|
|
call timer('xcor4 ',0)
|
||
|
|
call xcor4(s2,i,nsteps,nsym,ich,mode4)
|
||
|
|
call timer('xcor4 ',1)
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
|
||
|
|
return
|
||
|
|
end subroutine sync4
|
||
|
|
|