mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-01 08:07:10 -04:00
f9d0a1863a
This merge brings the WSPR feature development into the main line ready for release in a future v1.6 release. git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@5424 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
55 lines
1.4 KiB
Fortran
55 lines
1.4 KiB
Fortran
subroutine savec2(c2name,ntrseconds,f0m1500)
|
|
|
|
! Array c0() has complex samples at 1500 Hz sample rate.
|
|
! WSPR-2: downsample by 1/4 to produce c2, centered at 1500 Hz
|
|
! WSPR-15: downsample by 1/32 to produce c2, centered at 1612.5 Hz
|
|
|
|
parameter (NDMAX=120*1500) !Sample intervals at 1500 Hz rate
|
|
parameter (MAXFFT=256*1024)
|
|
|
|
character*(*) c2name
|
|
character*14 outfile
|
|
real*8 f0m1500
|
|
complex c0
|
|
complex c1(0:MAXFFT-1)
|
|
complex c2(0:65535)
|
|
common/c0com/c0(0:NDMAX-1)
|
|
|
|
ntrminutes=ntrseconds/60
|
|
npts=114*1500
|
|
nfft1=262144
|
|
if(ntrminutes.eq.15) then
|
|
npts=890*1500
|
|
nfft1=MAXFFT
|
|
endif
|
|
df1=1500.0/nfft1
|
|
fac=1.0/nfft1
|
|
c1(0:npts-1)=fac*c0(0:npts-1)
|
|
c1(npts:nfft1-1)=0.
|
|
|
|
call four2a(c1,nfft1,1,1,1) !Complex FFT to frequency domain
|
|
|
|
! Select the desired frequency range
|
|
nfft2=65536
|
|
nh2=nfft2/2
|
|
if(ntrminutes.eq.2) then
|
|
c2(0:nh2)=c1(0:nh2)
|
|
c2(nh2+1:nfft2-1)=c1(nfft1-nh2+1:nfft1-1)
|
|
else
|
|
i0=nint(112.5/df1)
|
|
c2(0:nh2)=c1(i0:i0+nh2)
|
|
c2(nh2+1:nfft2-1)=c1(i0-nh2+1:i0-1)
|
|
endif
|
|
|
|
call four2a(c2,nfft2,1,-1,1) !Shorter complex FFT, back to time domain
|
|
|
|
! Write complex time-domain data to disk.
|
|
i1=index(c2name,'.c2')
|
|
outfile=c2name(i1-11:i1+2)
|
|
open(18,file=c2name,status='unknown',access='stream')
|
|
write(18) outfile,ntrminutes,f0m1500,c2(0:45000-1)
|
|
close(18)
|
|
|
|
return
|
|
end subroutine savec2
|