WSJT-X/lib/t6.f90

57 lines
1.1 KiB
Fortran
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program t6
parameter (MAXFFT=1404)
complex c(0:MAXFFT-1)
real s(0:MAXFFT-1)
m1=45
m2=67
m3=89
nsym=3*11 + m1 + m2 + m3
nfft=6*nsym
nh=nfft/2
best=9999.
! do m1=22,67
! do m2=37,97
do m1=30,67
do m2=26,100
m3=201-m2-m1
if(m3.lt.13) cycle
c=0.
n1=6*(11+m1)
n2=n1+6*(11+m2)
c(1:66)=1.
c(1+n1:66+n1)=1.
c(1+n2:66+n2)=1.
call four2a(c,nfft,1,-1,1) !c2c FFT
df=12000.0/nfft
smax=0.
do i=0,nfft-1
s(i)=real(c(i))**2 + aimag(c(i))**2
if(i.ne.0) smax=max(s(i),smax)
enddo
sidelobe=db(smax/s(0))
if(sidelobe.lt.best) then
write(*,1000) m1,m2,m3,sidelobe
1000 format(3i5,f8.2)
best=sidelobe
s=s/s(0)
rewind 13
do j=0,nfft-1
i=mod(j+nh,nfft)
f=i*df
if(i.gt.nh) f=f-12000.0
write(13,1020) f,s(i)
1020 format(2f12.4)
enddo
endif
enddo
enddo
end program t6