WSJT-X/qmap/libqmap/symspec.f90

143 lines
3.6 KiB
Fortran

subroutine symspec(k,ndiskdat,nb,nbslider,nfsample, &
pxdb,ssz5a,nkhz,ihsym,nzap,slimit,lstrong)
! k pointer to the most recent new data
! ndiskdat 0/1 to indicate if data from disk
! nb 0/1 status of noise blanker
! nfsample sample rate (Hz)
! pxdb power in x channel (0-60 dB)
! ssz5a polarized spectrum, for waterfall display
! nkhz integer kHz portion of center frequency, e.g., 125 for 144.125
! ihsym index number of this half-symbol (1-322)
! nzap number of samples zero'ed by noise blanker
include 'njunk.f90'
parameter (NSMAX=60*96000) !Total sample intervals per minute
parameter (NFFT=32768) !Length of FFTs
real*8 ts,hsym
real*8 fcenter
common/datcom/dd(2,5760000),ss(322,NFFT),savg(NFFT),fcenter,nutc, &
junk(NJUNK)
real*4 ssz5a(NFFT),w(NFFT),w2a(NFFT),w2b(NFFT)
complex cx(NFFT)
complex cx00(NFFT)
complex cx0(0:1023),cx1(0:1023)
logical*1 lstrong(0:1023)
data rms/999.0/,k0/99999999/,nadjx/0/,nadjy/0/
save
nfast=1
if(k.gt.5751000) go to 999
if(k.lt.NFFT) then
ihsym=0
go to 999 !Wait for enough samples to start
endif
if(k0.eq.99999999) then
pi=4.0*atan(1.0)
w2a=0.
w2b=0.
do i=1,NFFT
w(i)=(sin(i*pi/NFFT))**2 !Window for nfast=1
if(i.lt.17833) w2a(i)=(sin(i*pi/17832.925))**2 !Window a for nfast=2
j=i-8916
if(j.gt.0 .and. j.lt.17833) w2b(i)=(sin(j*pi/17832.925))**2 ! b
enddo
w2a=sqrt(2.0)*w2a
w2b=sqrt(2.0)*w2b
endif
hsym=2048.d0*96000.d0/11025.d0 !Samples per JT65 half-symbol
if(nfsample.eq.95238) hsym=2048.d0*95238.1d0/11025.d0
if(k.lt.k0) then
ts=1.d0 - hsym
savg=0.
ihsym=0
k1=0
if(ndiskdat.eq.0) dd(1:2,k+1:5760000)=0. !### Should not be needed ??? ###
endif
k0=k
nzap=0
sigmas=1.5*(10.0**(0.01*nbslider)) + 0.7
peaklimit=sigmas*max(10.0,rms)
faclim=3.0
px=0.
nwindow=2
nfft2=1024
kstep=nfft2
if(nwindow.ne.0) kstep=nfft2/2
nblks=(k-k1)/kstep
do nblk=1,nblks
j=k1+1
do i=0,nfft2-1
cx0(i)=cmplx(dd(1,j+i),dd(2,j+i))
enddo
call timf2(k,nfft2,nwindow,nb,peaklimit, &
faclim,cx0,cx1,slimit,lstrong, &
px,nzap)
do i=0,kstep-1
dd(1,j+i)=real(cx1(i))
dd(2,j+i)=aimag(cx1(i))
enddo
k1=k1+kstep
enddo
npts=NFFT !Samples used in each half-symbol FFT
ts=ts+hsym
ja=ts !Index of first sample
jb=ja+npts-1 !Last sample
i=0
fac=0.0002
do j=ja,jb !Copy data into cx
x1=dd(1,j)
x2=dd(2,j)
i=i+1
cx(i)=fac*cmplx(x1,x2)
enddo
if(nzap/178.lt.50 .and. (ndiskdat.eq.0 .or. ihsym.lt.280)) then
nsum=nblks*kstep - nzap
if(nsum.le.0) nsum=1
rmsx=sqrt(0.5*px/nsum)
rms=rmsx
endif
pxdb=0.
if(rmsx.gt.1.0) pxdb=20.0*log10(rmsx)
if(pxdb.gt.60.0) pxdb=60.0
cx00=cx
do mm=1,nfast
ihsym=ihsym+1
if(nfast.eq.1) then
cx=w*cx00 !Apply window for 2nd forward FFT
else
if(mm.eq.1) then
cx=w2a*cx00
else
cx=w2b*cx00
endif
endif
call four2a(cx,NFFT,1,1,1) !Second forward FFT (X)
n=min(322,ihsym)
do i=1,NFFT
sx=real(cx(i))**2 + aimag(cx(i))**2
ss(n,i)=sx ! Pol = 0
savg(i)=savg(i) + sx
ssz5a(i)=sx
enddo
enddo
nkhz=nint(1000.d0*(fcenter-int(fcenter)))
if(fcenter.eq.0.d0) nkhz=125
999 return
end subroutine symspec