48 lines
1.2 KiB
Fortran
48 lines
1.2 KiB
Fortran
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subroutine getfc1w(c,fs,fa,fb,fc1,xsnr)
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include 'wsprlf_params.f90'
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complex c(0:NZ-1) !Complex waveform
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complex c2(0:NFFT1-1) !Short spectra
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real s(-NH1+1:NH1) !Coarse spectrum
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nspec=NZ/NFFT1
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df1=fs/NFFT1
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s=0.
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do k=1,nspec
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ia=(k-1)*N2
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ib=ia+N2-1
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c2(0:N2-1)=c(ia:ib)
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c2(N2:)=0.
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call four2a(c2,NFFT1,1,-1,1)
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do i=0,NFFT1-1
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j=i
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if(j.gt.NH1) j=j-NFFT1
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s(j)=s(j) + real(c2(i))**2 + aimag(c2(i))**2
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enddo
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enddo
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! call smo121(s,NFFT1)
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smax=0.
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ipk=0
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fc1=0.
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ia=nint(fa/df1)
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ib=nint(fb/df1)
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do i=ia,ib
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f=i*df1
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if(s(i).gt.smax) then
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smax=s(i)
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ipk=i
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fc1=f
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endif
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! write(51,3001) f,s(i),db(s(i))
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! 3001 format(f10.3,e12.3,f10.3)
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enddo
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! The following is for testing SNR calibration:
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sp3n=(s(ipk-1)+s(ipk)+s(ipk+1)) !Sig + 3*noise
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base=(sum(s)-sp3n)/(NFFT1-3.0) !Noise per bin
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psig=sp3n-3*base !Sig only
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pnoise=(2500.0/df1)*base !Noise in 2500 Hz
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xsnr=db(psig/pnoise)
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return
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end subroutine getfc1w
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