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Significantly improve MSK144 decoding of strong Es/tropo signals that occupy the full record.

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git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@7024 ab8295b8-cf94-4d9e-aec4-7959e3be5d79
This commit is contained in:
Steven Franke 2016-08-12 00:51:56 +00:00
parent 039c1681b7
commit c22239d019
2 changed files with 24 additions and 1 deletions
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24
lib/detectmsk144.f90
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@ -28,6 +28,7 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
logical ismask(NFFT)
real cbi(42),cbq(42)
real detmet(-2:MAXSTEPS+3)
real detmet2(-2:MAXSTEPS+3)
real detfer(MAXSTEPS)
real rcw(12)
real dd(NPTS)
@ -93,7 +94,7 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
! fill the detmet, detferr arrays
nstep=(n-NPTS)/216 ! 72ms/4=18ms steps
detmet=0
detmax=-999.99
detmet2=0
detfer=-999.99
do istp=1,nstep
ns=1+216*(istp-1)
@ -120,6 +121,8 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
ihpk=iloc(1)
deltah=-real( (ctmp(ihpk-1)-ctmp(ihpk+1)) / (2*ctmp(ihpk)-ctmp(ihpk-1)-ctmp(ihpk+1)) )
ah=tonespec(ihpk)
ahavp=(sum(tonespec,ismask)-ah)/count(ismask)
trath=ah/(ahavp+0.01)
illo=(2000-2*ntol)/df+1
ilhi=(2000+2*ntol)/df+1
ismask=.false.
@ -128,6 +131,8 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
ilpk=iloc(1)
deltal=-real( (ctmp(ilpk-1)-ctmp(ilpk+1)) / (2*ctmp(ilpk)-ctmp(ilpk-1)-ctmp(ilpk+1)) )
al=tonespec(ilpk)
alavp=(sum(tonespec,ismask)-al)/count(ismask)
tratl=al/(alavp+0.01)
fdiff=(ihpk+deltah-ilpk-deltal)*df
i2000=2000/df+1
i4000=4000/df+1
@ -139,6 +144,7 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
ferr=ferrl
endif
detmet(istp)=max(ah,al)
detmet2(istp)=max(trath,tratl)
detfer(istp)=ferr
enddo ! end of detection-metric and frequency error estimation loop
@ -161,6 +167,22 @@ subroutine detectmsk144(cbig,n,pchk_file,lines,nmessages,nutc,ntol,t00)
detmet(il)=0.0
enddo
if( ndet .lt. 3 ) then
do ip=1,MAXCAND-ndet ! Find candidates
iloc=maxloc(detmet2(1:nstep))
il=iloc(1)
if( (detmet2(il) .lt. 12.0) ) exit
if( abs(detfer(il)) .le. ntol ) then
ndet=ndet+1
times(ndet)=((il-1)*216+NSPM/2)*dt
ferrs(ndet)=detfer(il)
snrs(ndet)=12.0*log10(detmet2(il))/2-9.0
endif
! detmet2(max(1,il-1):min(nstep,il+1))=0.0
detmet2(il)=0.0
enddo
endif
nmessages=0
allmessages=char(0)
lines=char(0)

1
lib/msk144sim.f90
View File

@ -84,6 +84,7 @@ program msk144sim
do i=0,NMAX-1
xx=gran()
wave(i)=pings(i)*waveform(i) + fac*xx
! wave(i)=sig*waveform(i) + fac*xx
iwave(i)=30.0*wave(i)
enddo