WSJT-X/lib/iscat.f90

206 lines
5.2 KiB
Fortran
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subroutine iscat(cdat0,npts0,nh,npct,t2,pick,cfile6,minsync,ntol, &
NFreeze,MouseDF,mousebutton,mode4,nafc,nmore,psavg,maxlines,nlines,line)
! Decode an ISCAT signal
parameter (NMAX=30*3101)
parameter (NSZ=4*1400)
character cfile6*6 !File time
character c42*42
character msg*29,msg1*29,msgbig*29
character*80 line(100)
character csync*1
complex cdat0(NMAX)
complex cdat(NMAX)
real s0(288,NSZ)
real fs1(0:41,30)
real psavg(72) !Average spectrum of whole file
integer nsum(30)
integer ntol
integer icos(4)
logical pick,last
data icos/0,1,3,2/
data nsync/4/,nlen/2/,ndat/18/
data c42/'0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ /.?@-'/
nlines = 0
fsample=3100.78125 !Sample rate after 9/32 downsampling
nsps=144/mode4
bigworst=-1.e30 !Silence compiler warnings ...
bigxsync=0.
bigsig=-1.e30
msglenbig=0
ndf0big=0
nfdotbig=0
bigt2=0.
bigavg=0.
bigtana=0.
if(nmore.eq.-999) bigsig=-1 !... to here
last=.false.
do inf=1,6 !Loop over data-segment sizes
nframes=2**inf
if(nframes*24*nsps.gt.npts0) then
nframes=npts0/(24*nsps)
last=.true.
endif
npts=nframes*24*nsps
do ia=1,npts0-npts,nsps*24 !Loop over start times stepped by 1 frame
ib=ia+npts-1
cdat(1:npts)=cdat0(ia:ib)
t3=(ia + 0.5*npts)/fsample + 0.9
if(pick) t3=t2+t3
! Compute symbol spectra and establish sync:
call synciscat(cdat,npts,nh,npct,s0,jsym,df,ntol,NFreeze, &
MouseDF,mousebutton,mode4,nafc,psavg,xsync,sig,ndf0,msglen, &
ipk,jpk,idf,df1)
nfdot=nint(idf*df1)
isync=xsync
if(msglen.eq.0 .or. isync.lt.max(minsync,0)) then
msglen=0
worst=1.
avg=1.
ndf0=0
cycle
endif
ipk3=0 !Silence compiler warning
nblk=nsync+nlen+ndat
fs1=0.
nsum=0
nfold=jsym/96
jb=96*nfold
k=0
n=0
do j=jpk,jsym,4 !Fold information symbols into fs1
k=k+1
km=mod(k-1,nblk)+1
if(km.gt.6) then
n=n+1
m=mod(n-1,msglen)+1
ii=nint(idf*float(j-jb/2)/float(jb))
do i=0,41
iii=ii+ipk+2*i
if(iii.ge.1 .and. iii.le.288) fs1(i,m)=fs1(i,m) + s0(iii,j)
enddo
nsum(m)=nsum(m)+1
endif
enddo
do m=1,msglen
fs1(0:41,m)=fs1(0:41,m)/nsum(m)
enddo
! Read out the message contents:
msg= ' '
msg1=' '
mpk=0
worst=9999.
sum=0.
do m=1,msglen
smax=0.
smax2=0.
do i=0,41
if(fs1(i,m).gt.smax) then
smax=fs1(i,m)
ipk3=i
endif
enddo
do i=0,41
if(fs1(i,m).gt.smax2 .and. i.ne.ipk3) smax2=fs1(i,m)
enddo
rr=0.
if(smax2.gt.0.0) rr=smax/smax2
sum=sum + rr
if(rr.lt.worst) worst=rr
if(ipk3.eq.40) mpk=m
msg1(m:m)=c42(ipk3+1:ipk3+1)
enddo
avg=sum/msglen
if(mpk.eq.1) then
msg=msg1(2:)
else if(mpk.lt.msglen) then
msg=msg1(mpk+1:msglen)//msg1(1:mpk-1)
else
msg=msg1(1:msglen-1)
endif
ttot=npts/3100.78125
if(worst.gt.bigworst) then
bigworst=worst
bigavg=avg
bigxsync=xsync
bigsig=sig
ndf0big=ndf0
nfdotbig=nfdot
msgbig=msg
msglenbig=msglen
bigt2=t3
bigtana=nframes*24*nsps/fsample
endif
isync = xsync
if(avg.gt.2.5 .and. xsync.ge.max(float(minsync),1.5) .and. &
maxlines.ge.2) then
nsig=nint(sig)
nworst=10.0*(worst-1.0)
navg=10.0*(avg-1.0)
if(nworst.gt.10) nworst=10
if(navg.gt.10) navg=10
tana=nframes*24*nsps/fsample
csync=' '
if(isync.ge.1) csync='*'
if(nlines.le.maxlines-1) nlines = nlines + 1
write(line(nlines),1020) cfile6,isync,nsig,t2,ndf0,nfdot,csync, &
msg(1:28),msglen,navg,nworst,tana,char(0)
endif
enddo
if(last) exit
enddo
worst=bigworst
avg=bigavg
xsync=bigxsync
sig=bigsig
ndf0=ndf0big
nfdot=nfdotbig
msg=msgbig
msglen=msglenbig
t2=bigt2
tana=bigtana
isync=xsync
nworst=10.0*(worst-1.0)
navg=10.0*(avg-1.0)
if(nworst.gt.10) nworst=10
if(navg.gt.10) navg=10
if(navg.le.0 .or. isync.lt.max(minsync,0)) then
msg=' '
nworst=0
navg=0
ndf0=0
nfdot=0
sig=-20
msglen=0
tana=0.
t2=0.
endif
csync=' '
if(isync.ge.1) csync='*'
nsig=nint(sig)
if(nlines.le.maxlines-1) nlines = nlines + 1
write(line(nlines),1020) cfile6,isync,nsig,t2,ndf0,nfdot,csync,msg(1:28), &
msglen,navg,nworst,tana,char(0)
1020 format(a6,2i4,f5.1,i5,i4,1x,a1,2x,a28,i4,i3,2x,i1,f5.1,a1)
return
end subroutine iscat