WSJT-X/lib/symspec.f90

147 lines
3.7 KiB
Fortran
Raw Normal View History

subroutine symspec(k,ntrperiod,nsps,ndiskdat,nb,nbslider,pxdb,s,f0a,df3, &
ihsym,nzap,slimit,lstrong)
! Input:
! k pointer to the most recent new data
! ntrperiod T/R sequence length, minutes
! nsps samples per symbol (12000 Hz)
! ndiskdat 0/1 to indicate if data from disk
! nb 0/1 status of noise blanker (off/on)
! nbslider NB setting, 0-100
! Output:
! pxdb power (0-60 dB)
! s spectrum for waterfall display
! ihsym index number of this half-symbol (1-322)
! nzap number of samples zero'ed by noise blanker
! slimit NB scale adjustment
! lstrong true if strong signal at this freq
parameter (NMAX=1800*12000) !Total sample intervals per 30 minutes
parameter (NDMAX=1800*1500) !Sample intervals at 1500 Hz rate
parameter (NSMAX=22000) !Max length of saved spectra
parameter (NFFT1=1024)
parameter (NFFT2=1024,NFFT2A=NFFT2/8)
parameter (MAXFFT3=32768)
real*4 s(NSMAX),w(NFFT1),w3(MAXFFT3)
real*4 stmp(NFFT2/2)
real*4 x0(NFFT1),x1(NFFT1)
real*4 x2(NFFT2)
complex cx2(0:NFFT2/2)
complex cx2a(NFFT2A)
complex z,zfac
complex zsumx
complex cx(MAXFFT3)
complex cx00(NFFT1)
complex cx0(0:1023),cx1(0:1023)
logical*1 lstrong(0:1023) !Should be (0:512)
integer*2 id2
complex c0
common/jt9com/id2(NMAX),ss(184,NSMAX),savg(NSMAX),c0(NDMAX), &
nutc,npts8,junk(20)
equivalence (x2,cx2)
data rms/999.0/,k0/99999999/,ntrperiod0/0/,nfft3z/0/
save
if(ntrperiod.eq.1) nfft3=1024
if(ntrperiod.eq.2) nfft3=2048
if(ntrperiod.eq.5) nfft3=6144
if(ntrperiod.eq.10) nfft3=12288
if(ntrperiod.eq.30) nfft3=32768
jstep=nsps/16
if(k.gt.NMAX) go to 999
if(k.lt.nfft3) then
ihsym=0
go to 999 !Wait for enough samples to start
endif
if(nfft3.ne.nfft3z) then
pi=4.0*atan(1.0)
do i=1,nfft3
w3(i)=(sin(i*pi/nfft3))**2 !Window for nfft3
enddo
stmp=0.
nfft3z=nfft3
endif
if(k.lt.k0) then
ja=-2*jstep
savg=0.
ihsym=0
k1=0
k8=0
if(ndiskdat.eq.0) id2(k+1:)=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.
df2=12000.0/NFFT2
! nwindow=2
nwindow=0 !### No windowing ###
kstep1=NFFT1
if(nwindow.ne.0) kstep1=NFFT1/2
fac=1.0/(NFFT1*NFFT2)
nblks=(k-k1)/kstep1
do nblk=1,nblks
do i=1,NFFT1
x0(i)=fac*id2(k1+i)
enddo
call timf2(x0,k,NFFT1,nwindow,nb,peaklimit,faclim,x1, &
slimit,lstrong,px,nzap)
! x1=x0
x2=x1
call four2a(x2,NFFT2,1,-1,0) !Second forward FFT, r2c
i0=nint(1000.0/df2)
f0a=i0*df2
cx2a(1:NFFT2A/2)=cx2(i0:NFFT2A/2+i0-1)
cx2a(NFFT2A/2+1:NFFT2A)=cx2(i0-1-NFFT2A/2:i0-1)
call four2a(cx2a,NFFT2A,1,1,1)
c0(k8+1:k8+NFFT2A)=cx2a
npts8=k8+NFFT2A
!### Test for gliches at multiples of 128
! if(k8.lt.1000) then
! do i=k8+1,k8+NFFT2A
! write(82,4002) i,c0(i)
!4002 format(i8,2e12.3)
! enddo
! endif
!###
k1=k1+kstep1
k8=k8+kstep1/8
enddo
ja=ja+jstep !Index of first sample
if(ja.lt.0) go to 999
do i=1,nfft3 !Copy data into cx
cx(i)=c0(ja+i)
enddo
pxdb=0.
if(rmsx.gt.1.0) pxdb=20.0*log10(rmsx)
if(pxdb.gt.60.0) pxdb=60.0
ihsym=ihsym+1
call four2a(cx,nfft3,1,-1,1) !Third forward FFT (X)
n=min(184,ihsym)
df3=1500.0/nfft3
iz=min(NSMAX,nint(1000.0/df3))
do i=1,iz
sx=real(cx(i))**2 + aimag(cx(i))**2
ss(n,i)=sx
savg(i)=savg(i) + sx
s(i)=sx
enddo
999 return
end subroutine symspec