From 7e3b153d8b8c91c4330c3ec4eac4a8752eefdb77 Mon Sep 17 00:00:00 2001 From: Joe Taylor Date: Tue, 29 Jan 2019 13:56:04 -0500 Subject: [PATCH] Correct the estimate of SNR for FT4 signals. --- lib/ft4/ft4_decode.f90 | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/ft4/ft4_decode.f90 b/lib/ft4/ft4_decode.f90 index 790553bd1..0c2630438 100644 --- a/lib/ft4/ft4_decode.f90 +++ b/lib/ft4/ft4_decode.f90 @@ -74,7 +74,7 @@ subroutine ft4_decode(cdatetime0,nfqso,iwave,ndecodes,mycall,hiscall,nrx,line) ndecodes=0 do icand=1,ncand f0=candidate(1,icand) - xsnr=10*log10(candidate(3,icand))-15.0 + xsnr=10*log10(candidate(3,icand))-18.0 if( f0.le.375.0 .or. f0.ge.(5000.0-375.0) ) cycle call ft4_downsample(iwave,f0,cd2) ! downsample from 320 Sa/Symbol to 20 Sa/Symbol sum2=sum(cd2*conjg(cd2))/(20.0*76)