mirror of https://github.com/saitohirga/WSJT-X.git
93 lines
2.6 KiB
Fortran
93 lines
2.6 KiB
Fortran
subroutine rtping(dat,k,cfile6,MinSigdB,MouseDF,ntol,mycall)
|
|
|
|
! Called from datasink() every 2048 sample intervals (approx 43 ms).
|
|
! Detects pings (signal level above MinSigdB). When a ping ends, its
|
|
! MSK signal is synchronized and decoded.
|
|
|
|
parameter (NSMAX=30*48000)
|
|
parameter (NZMAX=703) !703 = NSMAX/2048
|
|
real dat(NSMAX) !Raw audio data
|
|
character*6 cfile6 !Time hhmmss at start of this Rx interval
|
|
character*12 mycall
|
|
real sig(NZMAX) !Sq-law detected signal, sampled at 43 ms
|
|
real sigdb(NZMAX) !Signal in dB, sampled at 43 ms
|
|
real tmp(NZMAX)
|
|
logical inside,pingFound
|
|
data k0/9999999/
|
|
save
|
|
|
|
if(k.lt.k0) then
|
|
inside=.false.
|
|
pingFound=.false.
|
|
j0=0
|
|
t1=0.
|
|
width=0.
|
|
peak=0.
|
|
tpk=0.
|
|
dt=1.0/48000.0
|
|
kstep=2048
|
|
sdt=dt*kstep
|
|
wmin=0.043
|
|
endif
|
|
k0=k
|
|
|
|
slim=MinSigdB
|
|
snrlim=10.0**(0.1*slim) - 1.0
|
|
sdown=10.0*log10(0.25*snrlim+1.0)
|
|
|
|
! Find signal power
|
|
j=k/kstep
|
|
sig(j)=dot_product(dat(k-kstep+1:k),dat(k-kstep+1:k))/kstep
|
|
if(j.lt.20) return
|
|
|
|
! Determine baseline noise level
|
|
if(mod(j,20).eq.0) call pctile (sig,tmp,j,50,base)
|
|
sigdb(j)=db(sig(j)/base) ! (S+N)/N in dB
|
|
|
|
! write(72,3001) j*sdt,base,sig(j),sigdb(j)
|
|
!3001 format(f10.3,3f12.6)
|
|
|
|
if(sigdb(j).ge.slim .and. .not.inside) then
|
|
j0=j !Mark the start of a ping
|
|
t1=j0*sdt
|
|
inside=.true.
|
|
peak=0.
|
|
endif
|
|
|
|
if(inside .and. sigdb(j).gt.peak) then
|
|
peak=sigdb(j) !Save peak strength
|
|
tpk=j*sdt ! and time of peak
|
|
endif
|
|
|
|
if(inside .and. (sigdb(j).lt.sdown .or. j.eq.NZMAX)) then
|
|
width=(j-j0)*sdt !Save ping width
|
|
if(width.ge.wmin) pingFound=.true.
|
|
endif
|
|
if(.not.pingFound) return
|
|
|
|
! A ping was found! Assemble a signal report:
|
|
nwidth=0
|
|
if(width.ge.0.04) nwidth=1
|
|
if(width.ge.0.12) nwidth=2
|
|
if(width.gt.1.00) nwidth=3
|
|
nstrength=6
|
|
if(peak.ge.11.0) nstrength=7
|
|
if(peak.ge.17.0) nstrength=8
|
|
if(peak.ge.23.0) nstrength=9
|
|
nrpt=10*nwidth + nstrength
|
|
|
|
mswidth=10*nint(100.0*width)
|
|
i1=(t1-0.02)/dt
|
|
if(i1.lt.1) i1=1
|
|
iz=nint((width+0.02)/dt) + 1
|
|
iz=min(iz,k+1-i1,2*48000) !Length of ping in samples
|
|
|
|
call jtmsk(dat(i1),iz,cfile6,tpk,mswidth,int(peak),nrpt, &
|
|
nfreeze,DFTolerance,MouseDF,pick,mycall)
|
|
|
|
pingFound=.false.
|
|
inside=.false.
|
|
|
|
return
|
|
end subroutine rtping
|