WSJT-X/lib/freqcal.f90
Joe Taylor 94e596589a Further progress toward a usable "FreqCal" (Frequency Calibration) mode.
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7448 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
2017-01-04 19:07:35 +00:00

52 lines
1018 B
Fortran

subroutine freqcal(id2,k,nfreq,ntol,line)
parameter (NZ=30*12000,NFFT=55296,NH=NFFT/2)
integer*2 id2(0:NZ-1)
real x(0:NFFT-1)
real s(NH)
character line*27
complex cx(0:NH)
equivalence (x,cx)
data n/0/,k0/9999999/
save n,k0
if(k.lt.k0) n=0
k0=k
x=0.001*id2(k-NFFT:k-1)
call four2a(x,NFFT,1,-1,0) !Compute spectrum, r2c
df=12000.0/NFFT
ia=nint((nfreq-ntol)/df)
ib=nint((nfreq+ntol)/df)
smax=0.
s=0.
do i=ia,ib
s(i)=real(cx(i))**2 + aimag(cx(i))**2
if(s(i).gt.smax) then
smax=s(i)
ipk=i
endif
enddo
call peakup(s(ipk-1),s(ipk),s(ipk+1),dx)
fpeak=df * (ipk+dx)
sum=0.
nsum=0
do i=ia,ib
if(abs(i-ipk).gt.10) then
sum=sum+s(i)
nsum=nsum+1
endif
enddo
ave=sum/nsum
pave=db(ave) + 8.0
snr=db(smax/ave)
! if(snr.lt.20.0) cflag='*'
n=n+1
write(line,1100) fpeak,snr
1100 format(2f8.1)
line(27:27)=char(0)
return
end subroutine freqcal