mirror of
https://github.com/saitohirga/WSJT-X.git
synced 2024-11-19 10:32:02 -05:00
2c17544f3f
git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/WSJT/trunk@1 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
178 lines
5.7 KiB
Fortran
178 lines
5.7 KiB
Fortran
subroutine short65(data,jz,NFreeze,MouseDF,DFTolerance,
|
|
+ mode65,nspecialbest,nstest,dfsh,iderrbest,idriftbest,
|
|
+ snrdb,ss1,ss2,nwsh)
|
|
|
|
C Checks to see if this might be a shorthand message.
|
|
C This is done before zapping, downsampling, or normal decoding.
|
|
|
|
parameter (NP2=60*11025) !Size of data array
|
|
parameter (NFFT=16384) !FFT length
|
|
parameter (NH=NFFT/2) !Step size
|
|
parameter (NQ=NFFT/4) !Saved spectral points
|
|
parameter (MAXSTEPS=60*11025/NH) !Max # of steps
|
|
|
|
real data(jz)
|
|
integer DFTolerance
|
|
real s2(NH,MAXSTEPS) !2d spectrum
|
|
real ss(NQ,4) !Save spectra in four phase bins
|
|
real psavg(NQ)
|
|
real sigmax(4) !Peak of spectrum at each phase
|
|
real ss1(-224:224) !Lower magenta curve
|
|
real ss2(-224:224) !Upper magenta curve
|
|
real ssavg(-10:10)
|
|
integer ipk(4) !Peak bin at each phase
|
|
save
|
|
|
|
nspecialbest=0 !Default return value
|
|
nstest=0
|
|
df=11025.0/NFFT
|
|
|
|
C Do 16 k FFTs, stepped by 8k. (*** Maybe should step by 4k? ***)
|
|
call zero(psavg,NQ)
|
|
nsteps=(jz-NH)/(4*NH)
|
|
nsteps=4*nsteps !Number of steps
|
|
do j=1,nsteps
|
|
k=(j-1)*NH + 1
|
|
call ps(data(k),NFFT,s2(1,j)) !Get power spectra
|
|
call add(psavg,s2(1,j),psavg,NQ)
|
|
enddo
|
|
|
|
call flat1(psavg,s2,NQ,nsteps,NH,MAXSTEPS)
|
|
|
|
nfac=40*mode65
|
|
dtstep=0.5/df
|
|
fac=dtstep/(60.0*df)
|
|
|
|
C Define range of frequencies to be searched
|
|
fa= 670.46
|
|
fb=1870.46
|
|
ia=fa/df
|
|
ib=fb/df + 4.1*nfac !Upper tone is above sync tone by 4*nfac*df Hz
|
|
if(ib.gt.NQ) ib=NQ
|
|
if(NFreeze.eq.1) then
|
|
fa=max( 670.46,1270.46+MouseDF-DFTolerance)
|
|
fb=min(1870.46,1270.46+MouseDF+DFTolerance)
|
|
endif
|
|
ia2=fa/df
|
|
ib2=fb/df + 4.1*nfac !Upper tone is above sync tone by 4*nfac*df Hz
|
|
if(ib2.gt.NQ) ib2=NQ
|
|
|
|
C Find strongest line in each of the 4 phases, repeating for each drift rate.
|
|
sbest=0.
|
|
snrbest=0.
|
|
idz=6.0/df !Is this the right drift range?
|
|
do idrift=-idz,idz
|
|
drift=idrift*df*60.0/49.04
|
|
call zero(ss,4*NQ) !Clear the accumulating array
|
|
do j=1,nsteps
|
|
n=mod(j-1,4)+1
|
|
k=nint((j-nsteps/2)*drift*fac) + ia
|
|
call add(ss(ia,n),s2(k,j),ss(ia,n),ib-ia+1)
|
|
enddo
|
|
|
|
do n=1,4
|
|
sigmax(n)=0.
|
|
do i=ia2,ib2
|
|
sig=ss(i,n)
|
|
if(sig.ge.sigmax(n)) then
|
|
ipk(n)=i
|
|
sigmax(n)=sig
|
|
if(sig.ge.sbest) then
|
|
sbest=sig
|
|
nbest=n
|
|
fdotsh=drift
|
|
endif
|
|
endif
|
|
enddo
|
|
enddo
|
|
n2best=nbest+2
|
|
if(n2best.gt.4) n2best=nbest-2
|
|
xdf=min(ipk(nbest),ipk(n2best))*df - 1270.46
|
|
if(NFreeze.eq.1 .and. abs(xdf-mousedf).gt.DFTolerance) goto 10
|
|
|
|
idiff=abs(ipk(nbest)-ipk(n2best))
|
|
xk=float(idiff)/nfac
|
|
k=nint(xk)
|
|
iderr=nint((xk-k)*nfac)
|
|
nspecial=0
|
|
maxerr=nint(0.008*abs(idiff) + 0.51)
|
|
if(abs(iderr).le.maxerr .and. k.ge.2 .and. k.le.4) nspecial=k
|
|
if(nspecial.gt.0) then
|
|
call getsnr(ss(ia2,nbest),ib2-ia2+1,snr1)
|
|
call getsnr(ss(ia2,n2best),ib2-ia2+1,snr2)
|
|
snr=0.5*(snr1+snr2)
|
|
if(snr.gt.snrbest) then
|
|
snrbest=snr
|
|
nspecialbest=nspecial
|
|
nstest=snr/2.0 - 2.0 !Threshold set here
|
|
if(nstest.lt.0) nstest=0
|
|
if(nstest.gt.10) nstest=10
|
|
dfsh=nint(xdf)
|
|
fdotbest=fdotsh
|
|
iderrbest=iderr
|
|
idiffbest=idiff
|
|
idriftbest=idrift
|
|
snrdb=db(snr) - db(2500.0/df) - db(sqrt(nsteps/4.0))+1.8
|
|
n1=nbest
|
|
n2=n2best
|
|
ipk1=ipk(n1)
|
|
ipk2=ipk(n2)
|
|
endif
|
|
endif
|
|
if(nstest.eq.0) nspecial=0
|
|
10 enddo
|
|
|
|
if(nstest.eq.0) nspecialbest=0
|
|
if(nstest.gt.0) then
|
|
df4=4.0*df
|
|
|
|
if(ipk1.gt.ipk2) then
|
|
ntmp=n1
|
|
n1=n2
|
|
n2=ntmp
|
|
ntmp=ipk1
|
|
ipk1=ipk2
|
|
ipk2=ntmp
|
|
endif
|
|
|
|
call zero(ss1,449)
|
|
call zero(ss2,449)
|
|
do i=ia2,ib2,4
|
|
f=df*i
|
|
k=nint((f-1270.46)/df4)
|
|
if(k.ge.-224 .and. k.le.224) then
|
|
ss1(k)=0.3 * (ss(i-2,n1) + ss(i-1,n1) + ss(i,n1) +
|
|
+ ss(i+1,n1) + ss(i+2,n1))
|
|
ss2(k)=0.3 * (ss(i-2,n2) + ss(i-1,n2) + ss(i,n2) +
|
|
+ ss(i+1,n2) + ss(i+2,n2))
|
|
endif
|
|
enddo
|
|
! kpk1=nint(0.25*ipk(n1)-472.0)
|
|
kpk1=nint(0.25*ipk1-472.0)
|
|
kpk2=kpk1 + nspecial*mode65*10
|
|
ssmax=0.
|
|
do i=-10,10
|
|
ssavg(i)=ss1(kpk1+i) + ss2(kpk2+i)
|
|
if(ssavg(i).gt.ssmax) then
|
|
ssmax=ssavg(i)
|
|
itop=i
|
|
endif
|
|
enddo
|
|
base=0.25*(ssavg(-10)+ssavg(-9)+ssavg(9)+ssavg(10))
|
|
shalf=0.5*(ssmax+base)
|
|
do k=1,8
|
|
if(ssavg(itop-k).lt.shalf) go to 110
|
|
enddo
|
|
k=8
|
|
110 x=(ssavg(itop-(k-1))-shalf)/(ssavg(itop-(k-1))-ssavg(itop-k))
|
|
do k=1,8
|
|
if(ssavg(itop+k).lt.shalf) go to 120
|
|
enddo
|
|
k=8
|
|
120 x=x+(ssavg(itop+(k-1))-shalf)/(ssavg(itop+(k-1))-ssavg(itop+k))
|
|
nwsh=nint(x*df4)
|
|
endif
|
|
|
|
return
|
|
end
|