subroutine analytic(d,npts,nfft,c,pc,beq) ! Convert real data to analytic signal parameter (NFFTMAX=1024*1024) real d(npts) ! passband signal real h(NFFTMAX/2) ! real BPF magnitude real*8 pc(5),pclast(5) ! static phase coeffs real*8 ac(5),aclast(5) ! amp coeffs real*8 fp complex corr(NFFTMAX/2) ! complex frequency-dependent correction complex c(NFFTMAX) ! analytic signal logical*1 beq ! boolean static equalizer flag data nfft0/0/ data aclast/1.0,0.0,0.0,0.0,0.0/ data ac/1.0,0.05532,0.11438,0.12918,0.09274/ ! amp coeffs for TS2000 save corr,nfft0,h,ac,aclast,pclast,pi,t,beta df=12000.0/nfft nh=nfft/2 if( nfft.ne.nfft0 ) then pi=4.0*atan(1.0) t=1.0/2000.0 beta=0.1 do i=1,nh+1 ff=(i-1)*df f=ff-1500.0 h(i)=1.0 if(abs(f).gt.(1-beta)/(2*t) .and. abs(f).le.(1+beta)/(2*t)) then h(i)=h(i)*0.5*(1+cos((pi*t/beta )*(abs(f)-(1-beta)/(2*t)))) elseif( abs(f) .gt. (1+beta)/(2*t) ) then h(i)=0.0 endif enddo nfft0=nfft endif if( any(aclast .ne. ac) .or. any(pclast .ne. pc) ) then aclast=ac pclast=pc write(*,3001) pc 3001 format('Phase coeffs:',5f12.6) do i=1,nh+1 ff=(i-1)*df f=ff-1500.0 fp=f/1000.0 corr(i)=ac(1)+fp*(ac(2)+fp*(ac(3)+fp*(ac(4)+fp*ac(5)))) pd=fp*fp*(pc(3)+fp*(pc(4)+fp*pc(5))) ! ignore 1st two terms corr(i)=corr(i)*cmplx(cos(pd),sin(pd)) enddo endif fac=2.0/nfft c(1:npts)=fac*d(1:npts) c(npts+1:nfft)=0. call four2a(c,nfft,1,-1,1) !Forward c2c FFT if( beq ) then c(1:nh+1)=h(1:nh+1)*corr(1:nh+1)*c(1:nh+1) else c(1:nh+1)=h(1:nh+1)*c(1:nh+1) endif c(1)=0.5*c(1) !Half of DC term c(nh+2:nfft)=0. !Zero the negative frequencies call four2a(c,nfft,1,1,1) !Inverse c2c FFT return end subroutine analytic