mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-05 00:41:19 -05:00
93 lines
2.1 KiB
Fortran
93 lines
2.1 KiB
Fortran
subroutine freqcal(id2,k,nkhz,noffset,ntol,line)
|
|
|
|
parameter (NZ=30*12000,NFFT=55296,NH=NFFT/2)
|
|
integer*2 id2(0:NZ-1)
|
|
complex sp,sn
|
|
real x(0:NFFT-1)
|
|
real xi(0:NFFT-1)
|
|
real w(0:NFFT-1) !Window function
|
|
real s(0:NH)
|
|
character line*80,cflag*1
|
|
logical first
|
|
complex cx(0:NH)
|
|
equivalence (x,cx)
|
|
data n/0/,k0/9999999/,first/.true./
|
|
save n,k0,w,first,pi,fs,xi
|
|
|
|
if(first) then
|
|
pi=4.0*atan(1.0)
|
|
fs=12000.0
|
|
do i=0,NFFT-1
|
|
ww=sin(i*pi/NFFT)
|
|
w(i)=ww*ww/NFFT
|
|
xi(i)=2.0*pi*i
|
|
enddo
|
|
first=.false.
|
|
endif
|
|
|
|
if(k.lt.NFFT) go to 900
|
|
if(k.lt.k0) n=0
|
|
k0=k
|
|
|
|
x=w*id2(k-NFFT:k-1) !Apply window
|
|
call four2a(x,NFFT,1,-1,0) !Compute spectrum, r2c
|
|
df=fs/NFFT
|
|
if (ntol.gt.noffset) then
|
|
ia=0
|
|
ib=nint((noffset*2)/df)
|
|
else
|
|
ia=nint((noffset-ntol)/df)
|
|
ib=nint((noffset+ntol)/df)
|
|
endif
|
|
smax=0.
|
|
s=0.
|
|
ipk=-99
|
|
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
|
|
|
|
if(ipk.ge.1) then
|
|
call peakup(s(ipk-1),s(ipk),s(ipk+1),dx)
|
|
fpeak=df * (ipk+dx)
|
|
ap=(fpeak/fs+1.0/(2.0*NFFT))
|
|
an=(fpeak/fs-1.0/(2.0*NFFT))
|
|
sp=sum(id2((k-NFFT):k-1)*cmplx(cos(xi*ap),-sin(xi*ap)))
|
|
sn=sum(id2((k-NFFT):k-1)*cmplx(cos(xi*an),-sin(xi*an)))
|
|
fpeak=fpeak+fs*(abs(sp)-abs(sn))/(abs(sp)+abs(sn))/(2*NFFT)
|
|
xsum=0.
|
|
nsum=0
|
|
do i=ia,ib
|
|
if(abs(i-ipk).gt.10) then
|
|
xsum=xsum+s(i)
|
|
nsum=nsum+1
|
|
endif
|
|
enddo
|
|
ave=xsum/nsum
|
|
snr=db(smax/ave)
|
|
pave=db(ave) + 8.0
|
|
else
|
|
snr=-99.9
|
|
pave=-99.9
|
|
fpeak=-99.9
|
|
ferr=-99.9
|
|
endif
|
|
cflag=' '
|
|
if(snr.lt.20.0) cflag='*'
|
|
n=n+1
|
|
nsec=mod(time(),86400)
|
|
nhr=nsec/3600
|
|
nmin=mod(nsec/60,60)
|
|
nsec=mod(nsec,60)
|
|
ncal=1
|
|
ferr=fpeak-noffset
|
|
write(line,1100) nhr,nmin,nsec,nkhz,ncal,noffset,fpeak,ferr,pave, &
|
|
snr,cflag,char(0)
|
|
1100 format(i2.2,':',i2.2,':',i2.2,i7,i3,i6,2f10.3,2f7.1,2x,a1,a1)
|
|
|
|
900 return
|
|
end subroutine freqcal
|