subroutine symspec(k,ntrperiod,nsps,ingain,slope,pxdb,s,df3,ihsym,npts8) ! Input: ! k pointer to the most recent new data ! ntrperiod T/R sequence length, minutes ! nsps samples per symbol, at 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() current spectrum for waterfall display ! ihsym index number of this half-symbol (1-184) ! jt9com ! ss() JT9 symbol spectra at half-symbol steps ! savg() average spectra for waterfall display include 'constants.f90' real*4 w3(MAXFFT3) real*4 s(NSMAX) real*4 scale(NSMAX) real*4 ssum(NSMAX) real*4 xc(0:MAXFFT3-1) complex cx(0:MAXFFT3/2) integer*2 id2 common/jt9com/ss(184,NSMAX),savg(NSMAX),id2(NMAX),nutc,ndiskdat, & ntr,mousefqso,newdat,nfa,nfb,ntol,kin,nzhsym,nsynced,ndecoded data rms/999.0/,k0/99999999/,nfft3z/0/,slope0/0.0/ equivalence (xc,cx) save if(ntrperiod.eq.-999) stop !Silence compiler warning nfft3=16384 !df=12000.0/16384 = 0.732422 jstep=nsps/2 !Step size = half-symbol in id2() if(k.gt.NMAX) go to 900 if(k.lt.2048) then !(2048 was nfft3) (Any need for this ???) ihsym=0 go to 900 !Wait for enough samples to start endif if(nfft3.ne.nfft3z .or. slope.ne.slope0) then !New nfft3, compute window pi=4.0*atan(1.0) do i=1,nfft3 w3(i)=2.0*(sin(i*pi/nfft3))**2 !Window for nfft3 spectrum enddo nfft3z=nfft3 nh=NSMAX/2 do i=1,NSMAX x=slope*float(i)/nh - 1.0 + 2.6 scale(i)=10.0**x enddo slope0=slope endif if(k.lt.k0) then !Start a new data block ja=0 ssum=0. ihsym=0 if(ndiskdat.eq.0) id2(k+1:)=0 !Needed to prevent "ghosts". Not sure why. endif gain=10.0**(0.05*ingain) sq=0. do i=k0+1,k x1=id2(i) sq=sq + x1*x1 enddo sq=sq * gain**2 rms=sqrt(sq/(k-k0)) pxdb=0. if(rms.gt.0.0) pxdb=20.0*log10(rms) if(pxdb.gt.60.0) pxdb=60.0 k0=k ja=ja+jstep !Index of first sample fac0=0.1 do i=0,nfft3-1 !Copy data into cx j=ja+i-(nfft3-1) xc(i)=0. if(j.ge.1) xc(i)=fac0*id2(j) enddo if(ihsym.lt.184) ihsym=ihsym+1 xc(0:nfft3-1)=w3(1:nfft3)*xc(0:nfft3-1) !Apply window w3 call four2a(xc,nfft3,1,-1,0) !Real-to-complex FFT n=min(184,ihsym) df3=12000.0/nfft3 !JT9-1: 0.732 Hz = 0.42 * tone spacing ! i0=nint(1000.0/df3) i0=0 iz=min(NSMAX,nint(5000.0/df3)) fac=(1.0/nfft3)**2 do i=1,iz j=i0+i-1 if(j.lt.0) j=j+nfft3 sx=fac*(real(cx(j))**2 + aimag(cx(j))**2) ss(n,i)=sx ssum(i)=ssum(i) + sx s(i)=gain*sx enddo ! s=0.05*s/ref s=scale*s savg=scale*ssum/ihsym 900 npts8=k/8 return end subroutine symspec