Increase the JT65 range of acceptable DT: now -2 to +5 s. Note that

displayed DT values appear to be to low by 0.2 s -- they range from
-2.2 s to +4.8 s, according to files generated by jt65sim.


git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@6179 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

lib/afc65b.f90

@@ -9,10 +9,6 @@ subroutine afc65b(cx,npts,fsample,nflip,a,ccfbest,dtbest)
   a(2)=0.
   a(3)=0.
   a(4)=0.
-!  deltaa(1)=2.0
-!  deltaa(2)=2.0
-!  deltaa(3)=2.0
-!  deltaa(4)=0.05
   deltaa(1)=2.0
   deltaa(2)=2.0
   deltaa(3)=1.0

lib/ccf2.f90

@@ -1,7 +1,6 @@
 subroutine ccf2(ss,nz,nflip,ccfbest,xlagpk)
 
-!  parameter (LAGMAX=60)
-  parameter (LAGMAX=200)
+  parameter (LAGMIN=-86,LAGMAX=258)
   real ss(nz)
   real ccf(-LAGMAX:LAGMAX)
   integer npr(126)
@@ -18,7 +17,7 @@ subroutine ccf2(ss,nz,nflip,ccfbest,xlagpk)
   save
 
   ccfbest=0.
-  lag1=-LAGMAX
+  lag1=LAGMIN
   lag2=LAGMAX
   do lag=lag1,lag2
      s0=0.
@@ -38,6 +37,7 @@ subroutine ccf2(ss,nz,nflip,ccfbest,xlagpk)
      if(ccf(lag).gt.ccfbest) then
         ccfbest=ccf(lag)
         lagpk=lag
+        xlagpk=lagpk
      endif
   enddo
   if( lagpk.gt.-LAGMAX .and. lagpk.lt.LAGMAX) then

lib/decode65a.f90

@@ -50,14 +50,17 @@ subroutine decode65a(dd,npts,newdat,nqd,f0,nflip,mode65,ntrials,     &
   nsym=126
   nfft=512
   j=int(dtbest*1378.125)
-  if(j.lt.0) j=0
 
   c5a=cmplx(0.0,0.0)
   call timer('sh_ffts ',0)
   do k=1,nsym
      do i=1,nfft
         j=j+1
-        if( j .le. NMAX/8 ) c5a(i)=cx(j)
+        if(j.ge.1 .and. j.le.NMAX/8) then
+           c5a(i)=cx(j)
+        else
+           c5a(i)=0.
+        endif
      enddo
      call four2a(c5a,nfft,1,1,1)
      do i=1,66

lib/fchisq65.f90

@@ -60,7 +60,7 @@ real function fchisq65(cx,npts,fsample,nflip,a,ccfmax,dtmax)
      dtmax=xlagpk*dtstep
   endif
   fchisq65=-ccfmax
-
   call timer('fchisq65',1)
+
   return
 end function fchisq65

lib/fillcom.f90

@@ -23,6 +23,12 @@ subroutine fillcom(nutc0,ndepth0,nrxfreq,mode,tx9,flow,fsplit,fhigh)
   nzhsym=181
   ndepth=ndepth0
   dttol=3.0
+
+  n2pass=1
+  nranera=8
+  naggressive=10
+  nrobust=0
+
   if (tx9) then
     ntxmode=9
   else

lib/jt65sim.f90

@@ -28,9 +28,9 @@ program jt65sim
             1,1,1,1,1,1/
 
   nargs=iargc()
-  if(nargs.ne.5) then
-     print*,'Usage:   jt65sim mode nsigs fspread SNR nfiles'
-     print*,'Example: jt65sim   A    10    0.2   -24    1'
+  if(nargs.ne.6) then
+     print*,'Usage:   jt65sim mode nsigs fspread SNR  DT  nfiles'
+     print*,'Example: jt65sim   A    10    0.2   -24  0.0   1'
      print*,'Enter SNR = 0 to generate a range of SNRs.'
      go to 999
   endif
@@ -47,6 +47,8 @@ program jt65sim
   call getarg(4,arg)
   read(arg,*) snrdb                  !S/N in dB (2500 hz reference BW)
   call getarg(5,arg)
+  read(arg,*) xdt                    !Generated DT
+  call getarg(6,arg)
   read(arg,*) nfiles                 !Number of files     
 
   rms=100.
@@ -106,7 +108,7 @@ program jt65sim
 
         phi=0.d0
         dphi=0.d0
-        k=12000                             !Start audio at t = 1.0 s
+        k=12000 + xdt*12000                 !Start audio at t = xdt + 1.0 s
         isym0=-99
         do i=1,npts                         !Add this signal into cdat()
            isym=nint(i/sps)+1
@@ -121,7 +123,7 @@ program jt65sim
            xphi=phi
            z=cmplx(cos(xphi),sin(xphi))
            k=k+1
-           cdat(k)=cdat(k) + sig*z
+           if(k.ge.1) cdat(k)=cdat(k) + sig*z
         enddo
      enddo
 

lib/sync65.f90

@@ -2,7 +2,7 @@ subroutine sync65(ss,nfa,nfb,nhsym,ca,ncand,nrobust)
 
   parameter (NSZ=3413,NFFT=8192,MAXCAND=300)
   real ss(322,NSZ)
-  real ccfblue(-5:540)             !CCF with pseudorandom sequence
+  real ccfblue(-11:540)             !CCF with pseudorandom sequence
   real ccfred(NSZ)                 !Peak of ccfblue, as function of freq
   
   type candidate
@@ -18,7 +18,7 @@ subroutine sync65(ss,nfa,nfb,nhsym,ca,ncand,nrobust)
   df=12000.0/NFFT                            !df = 12000.0/16384 = 0.732 Hz
   ia=max(2,nint(nfa/df))
   ib=min(NSZ-1,nint(nfb/df))
-  lag1=-5
+  lag1=-11
   lag2=59
   nsym=126
 !!  thresh0=5.5

lib/xcor.f90

@@ -9,7 +9,7 @@ subroutine xcor(ss,ipk,nsteps,nsym,lag1,lag2,ccf,ccf0,lagpk,flip,fdot,nrobust)
   parameter (NSMAX=322)            !Max number of half-symbol steps
   real ss(NSMAX,NHMAX)             !2d spectrum, stepped by half-symbols
   real a(NSMAX)
-  real ccf(-5:540)
+  real ccf(-11:540)
   include 'prcom.f90'
   data lagmin/0/                              !Silence g77 warning
   save