From e5a8e80c495e7eddf78bfdaa2746a977bc050152 Mon Sep 17 00:00:00 2001
From: Joe Taylor <joe@princeton.edu>
Date: Fri, 1 Jan 2021 15:28:41 -0500
Subject: [PATCH] Minor tweaks to Q^% decoding scheme.

---
 lib/qra/q65/q65_avg.f90   |  8 ++++----
 lib/qra/q65/q65_loops.f90 | 28 ++++++++++++++--------------
 lib/test_q65.f90          |  6 +++---
 3 files changed, 21 insertions(+), 21 deletions(-)

diff --git a/lib/qra/q65/q65_avg.f90 b/lib/qra/q65/q65_avg.f90
index 85fda7fc7..b90a7a227 100644
--- a/lib/qra/q65/q65_avg.f90
+++ b/lib/qra/q65/q65_avg.f90
@@ -23,7 +23,6 @@ subroutine q65_avg(nutc,ntrperiod,LL,nfqso,ntol,lclearave,xdt,f0,snr1,s3)
      iutc=-1
      iseq=-1
      f0save=0.0
-     dtdiff=0.2
      nsave=0
      LL0=LL
      first=.false.
@@ -73,6 +72,7 @@ subroutine q65_avg(nutc,ntrperiod,LL,nfqso,ntol,lclearave,xdt,f0,snr1,s3)
 
   if(nsave.lt.2) go to 900
   mode_q65=2**nsubmode
+  f0diff=baud*mode_q65
   ibwa=1.8*log(baud*mode_q65) + 2
   ibwb=min(10,ibwa+4)
   snr1sum=0.
@@ -87,7 +87,7 @@ subroutine q65_avg(nutc,ntrperiod,LL,nfqso,ntol,lclearave,xdt,f0,snr1,s3)
      if(iutc(i).lt.0) cycle
      if(iseq(i).ne.iseq(nsave)) cycle               !Sequence must match
      if(abs(xdt-xdtsave(i)).gt.dtdiff) cycle        !DT must be close
-     if(abs(f0-f0save(i)).gt.float(ntol)) cycle   !Freq must match
+     if(abs(f0-f0save(i)).gt.f0diff) cycle          !Freq must match
      cused(i)='$'                                   !Flag for "use this one"
      s3avg=s3avg + s3save(:,:,i)                    !Add this spectrum
      snr1sum=snr1sum + snr1save(i)
@@ -97,7 +97,6 @@ subroutine q65_avg(nutc,ntrperiod,LL,nfqso,ntol,lclearave,xdt,f0,snr1,s3)
      iused(navg)=i
   enddo
   if(navg.lt.MAXAVE) iused(navg+1)=0
-  if(navg.lt.2) go to 900
   
 ! Find averages of snr1, xdt, and f0 used in this decoding attempt.
   snr1ave=0.
@@ -118,6 +117,7 @@ subroutine q65_avg(nutc,ntrperiod,LL,nfqso,ntol,lclearave,xdt,f0,snr1,s3)
           xdtsave(i),f0save(i)
 1001 format(a1,i5.4,f6.1,f6.2,f7.1)
   enddo
+  if(navg.lt.2) go to 900
 
   s3avg=s3avg/navg
   nFadingModel=1
@@ -129,7 +129,7 @@ subroutine q65_avg(nutc,ntrperiod,LL,nfqso,ntol,lclearave,xdt,f0,snr1,s3)
      call timer('dec1avg ',1)
      if(irc.ge.0) then
         snr2=esnodb - 0.5*db(2500.0/baud) + 3.0     !Empirical adjustment
-        snr2=snr2 - db(float(navg))             !Is this right?
+        snr2=snr2 - db(float(navg))                 !Is this right?
         idec=100+navg
         go to 900
      endif
diff --git a/lib/qra/q65/q65_loops.f90 b/lib/qra/q65/q65_loops.f90
index b3c4eece8..ce476c0fb 100644
--- a/lib/qra/q65/q65_loops.f90
+++ b/lib/qra/q65/q65_loops.f90
@@ -35,14 +35,13 @@ subroutine q65_loops(c00,npts2,nsps,mode_q65,nsubmode,ndepth,jpk0,    &
   if(iand(ndepth,3).ge.2) then
      idfmax=5
      idtmax=5
-     maxdist=15
+     maxdist=10
   endif
   if(iand(ndepth,3).eq.3) then
-     maxdist=25
+     maxdist=15
      ibwa=max(1,ibwa-1)
      ibwb=min(10,ibwb+1)
   endif
-
   
   LL=64*(mode_q65+2)
   napmin=99
@@ -57,17 +56,15 @@ subroutine q65_loops(c00,npts2,nsps,mode_q65,nsubmode,ndepth,jpk0,    &
      call twkfreq(c00,c0,npts2,6000.0,a)
      do idt=1,idtmax
         ndt=idt/2
-        if(iaptype.eq.0) then
-           if(mod(idt,2).eq.0) ndt=-ndt
-           jpk=jpk0 + nsps*ndt/16              !tsym/16
-           if(jpk.lt.0) jpk=0
-           call timer('spec64  ',0)
-           call spec64(c0,nsps,65,mode_q65,jpk,s3,LL,NN)
-           call timer('spec64  ',1)
-           call pctile(s3,LL*NN,40,base)
-           s3=s3/base
-           where(s3(1:LL*NN)>s3lim) s3(1:LL*NN)=s3lim
-        endif
+        if(mod(idt,2).eq.0) ndt=-ndt
+        jpk=jpk0 + nsps*ndt/16              !tsym/16
+        if(jpk.lt.0) jpk=0
+        call timer('spec64  ',0)
+        call spec64(c0,nsps,65,mode_q65,jpk,s3,LL,NN)
+        call timer('spec64  ',1)
+        call pctile(s3,LL*NN,40,base)
+        s3=s3/base
+        where(s3(1:LL*NN)>s3lim) s3(1:LL*NN)=s3lim
         do ibw=ibwa,ibwb
            ndist=ndf**2 + ndt**2 + (ibw-ibw0)**2
            if(ndist.gt.maxdist) cycle
@@ -87,6 +84,9 @@ subroutine q65_loops(c00,npts2,nsps,mode_q65,nsubmode,ndepth,jpk0,    &
   enddo  ! idf (f0 loop)
 
 100 if(irc.ge.0) then
+!     write(55,3055) ndepth,iaptype,idf,idt,ibw,ndist,irc,sum(s3(1:LL*NN)), &
+!          trim(decoded)
+!3055 format(7i4,f10.1,1x,a)
      idec=iaptype+2
      snr2=esnodb - db(2500.0/baud)
      xdt1=xdt0 +  nsps*ndt/(16.0*6000.0)
diff --git a/lib/test_q65.f90 b/lib/test_q65.f90
index cf557591d..710220a8a 100644
--- a/lib/test_q65.f90
+++ b/lib/test_q65.f90
@@ -4,7 +4,7 @@ program test_q65
   character*22 msg
   character*8 arg
   character*1 csubmode
-  integer naptype(1:6)
+  integer naptype(0:5)
   logical decok
 
   nargs=iargc()
@@ -93,8 +93,8 @@ program test_q65
 !1000 format(/'Depth:',i2,'  AP:',i2,'  df:',i3,'  dt:',i3,'  bw1:',i3,'  bw2:',i3,  &
 !          '  dist:',i3)
   
-  write(*,1010) (j,j=1,6)
-  write(12,1010) (j,j=1,6)
+  write(*,1010) (j,j=0,5)
+  write(12,1010) (j,j=0,5)
 1010 format(' SNR  Mode  d Dop Sync Avg Dec Bad',6i4,'  tdec   avg  rms'/  &
           75('-'))