mirror of https://github.com/saitohirga/WSJT-X.git
68 lines
1.6 KiB
Fortran
68 lines
1.6 KiB
Fortran
program test_snr
|
|
|
|
! Test an algorithm for measuring SNR of EME echoes.
|
|
|
|
use wavhdr
|
|
parameter (NMAX=27648) !27*1024
|
|
parameter (NFFT=32768,NH=NFFT/2)
|
|
parameter (NZ=4096)
|
|
|
|
type(hdr) h !Header for the .wav file
|
|
integer*2 id2(NMAX) !Buffer for Rx data
|
|
complex c(0:NH)
|
|
real x(NFFT)
|
|
real s(8192)
|
|
real sa(4096)
|
|
real sb(4096)
|
|
real red(4096)
|
|
real blue(4096)
|
|
character*80 infile
|
|
equivalence (x,c)
|
|
|
|
nargs=iargc()
|
|
if(nargs.lt.1) then
|
|
print*,'Usage: test_snr <infile>'
|
|
go to 999
|
|
endif
|
|
call getarg(1,infile)
|
|
i0=index(infile,'_')
|
|
read(infile(1:i0-1),*) fspread0 !Generated Doppler spread
|
|
read(infile(i0+1:i0+3),*) snrdb0 !Generated SNR
|
|
open(10,file=trim(infile),status='old',access='stream')
|
|
read(10) h
|
|
npts=h%ndata/2
|
|
npings=npts/NMAX
|
|
nfsample=h%nsamrate
|
|
df=12000.0/NFFT
|
|
s=0.
|
|
fac=1.0/NMAX
|
|
|
|
do iping=1,npings
|
|
read(10) id2(1:NMAX)
|
|
x(1:NMAX)=fac*id2(1:NMAX)
|
|
x(NMAX+1:)=0.
|
|
call four2a(x,NFFT,1,-1,0)
|
|
do i=1,8192 !Accumulate spectrum 0 - 3 kHz
|
|
s(i)=s(i) + real(c(i))**2 + aimag(c(i))**2
|
|
enddo
|
|
enddo
|
|
|
|
sa=s(2049:6144)
|
|
sb=s(2049:6144)
|
|
|
|
call echo_snr(sa,sb,fspread0,blue,red,snrdb,db_err,fpeak,snr_detect)
|
|
|
|
nqual=min(10,int(snr_detect-4.0))
|
|
|
|
write(*,1010) fspread0,snrdb0,snrdb,snrdb-snrdb0,db_err,fpeak, &
|
|
snr_detect,nqual
|
|
|
|
1010 format(5f6.1,2f7.1,i4)
|
|
|
|
do i=1,8192
|
|
write(12,1100) i*df,s(i)
|
|
1100 format(f10.3,e15.6)
|
|
enddo
|
|
|
|
999 end program test_snr
|