Return-Path: X-Spam-DCC: paranoid 1233; Body=3 Fuz1=3 Fuz2=3 X-Spam-Checker-Version: SpamAssassin 3.1.3 (2006-06-01) on lipkowski.org X-Spam-Level: X-Spam-Status: No, score=-0.5 required=5.0 tests=BAYES_00,DNS_FROM_AHBL_RHSBL, FORGED_RCVD_HELO,RATWARE_GECKO_BUILD autolearn=no version=3.1.3 Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by paranoid.lipkowski.org (8.13.7/8.13.7) with ESMTP id tATNYYqx031653 for ; Mon, 30 Nov 2015 00:34:34 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1a3BRH-0000KB-Ti for rs_out_1@blacksheep.org; Sun, 29 Nov 2015 23:31:27 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1a3BRH-0000K2-Fy for rsgb_lf_group@blacksheep.org; Sun, 29 Nov 2015 23:31:27 +0000 Received: from parrot.netcom.co.uk ([217.72.171.49]) by relay1.thorcom.net with esmtp (Exim 4.86) (envelope-from ) id 1a3BQD-0005TU-A9 for rsgb_lf_group@blacksheep.org; Sun, 29 Nov 2015 23:31:26 +0000 Received: from sb.abelian.org (i-194-106-52-83.freedom2surf.net [194.106.52.83]) by parrot.netcom.co.uk (Postfix) with ESMTP id E8ADD3273E8 for ; Sun, 29 Nov 2015 23:21:09 +0000 (GMT) Received: from [127.0.0.1] (localhost [127.0.0.1]) by sb.abelian.org (Postfix) with ESMTP id 29BDD28A01BE for ; Sun, 29 Nov 2015 23:30:04 +0000 (UTC) Message-ID: <565B8A7B.8000608@abelian.org> Date: Sun, 29 Nov 2015 23:30:03 +0000 From: Paul Nicholson User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: rsgb_lf_group@blacksheep.org References: <8D2F8A79EEF4432-1FFC-66476@webmail-vd018.sysops.aol.com> <565B3DE9.7040401@abelian.org> <565B6B1F.4070606@abelian.org> <565B70FC.1090505@abelian.org> In-Reply-To: X-Scan-Signature: 3f8d74a8c70dd416d0a3a1dbcb9bb89f Subject: Re: LF: More EbNaut 137.777 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-SA-Exim-Scanned: Yes Sender: owner-rsgb_lf_group@blacksheep.org Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group X-SA-Exim-Rcpt-To: rs_out_1@blacksheep.org X-SA-Exim-Scanned: No; SAEximRunCond expanded to false X-Scanned-By: MIMEDefang 2.56 on 10.1.3.10 Status: O X-Status: X-Keywords: X-UID: 5455 VO1NA 2015-11-29 8K19A 2S 5C 20:00 6.2 dB 20:30 7.0 dB 21:00 3.2 dB 21:30 1.4 dB 22:00 5.4 dB 22:30 no decode 23:00 8.7 dB Edgar wrote: > I had been looking at vtmatch. vtmatch monitors a stream and does a continuous cross correlation against the template: in other words a matched filter. It would be the one to use if you knew what the message was but not the start times. Generate a template file for vtmatch with echo 'TNX PAUL' | ebnaut -e -r100 -S2 -p8K19A -N8 | awk '{print $1}' > ref.dat Here, I've dropped to sample rate 100. I should then be able to do something like vtread -T2015-11-28_20:00,+8h /raw | # Get 8 hours of signal vtfilter -h bp,f=2777,w=2 | vtmult -f 2777 | # Mix 137777 to baseband vtresample -r 100 | # Baseband I/Q at 100 samples/sec vtmatch -t ref.dat > match.vt Then vtplot match.vt should show a good spike whenever the message appears in that 8 hour stream. The spike should be surrounded by auto-correlation 'sidebands' which ought to be quite low compared to the peak. For some reason it's not quite working, getting the sidebands but no central spike, even on a simulated signal. Maybe I'm too tired or there's a bug in vtmatch. I'll look at it again tomorrow. -- Paul Nicholson --