Return-Path: Received: (qmail 27997 invoked from network); 9 Aug 2002 19:51:54 -0000 Received: from marstons.services.quay.plus.net (212.159.14.223) by mailstore with SMTP; 9 Aug 2002 19:51:54 -0000 Received: (qmail 13723 invoked by uid 10001); 9 Aug 2002 19:56:23 -0000 Received: from post.thorcom.com (193.82.116.70) by marstons.services.quay.plus.net with SMTP; 9 Aug 2002 19:56:23 -0000 X-SQ: A Received: from majordom by post.thorcom.com with local (Exim 3.33 #2) id 17dHUu-0004IJ-00 for rsgb_lf_group-outgoing@blacksheep.org; Fri, 09 Aug 2002 22:40:40 +0100 Received: from fep04.swip.net ([130.244.199.132] helo=fep04-svc.swip.net) by post.thorcom.com with esmtp (Exim 3.33 #2) id 17dHUt-0004IE-00 for rsgb_lf_group@blacksheep.org; Fri, 09 Aug 2002 22:40:39 +0100 Received: from oemcomputer ([213.101.38.34]) by fep04-svc.swip.net with SMTP id <20020809194828.WAHE26352.fep04-svc.swip.net@oemcomputer> for ; Fri, 9 Aug 2002 21:48:28 +0200 Message-ID: <003401c23fdd$c3067da0$222665d5@oemcomputer> From: "Johan Bodin" To: rsgb_lf_group@blacksheep.org References: Subject: LF: Re: SM6LKM Jason beacon affected by multipath Date: Fri, 9 Aug 2002 21:47:41 +0200 MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2600.0000 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Precedence: bulk Reply-To: rsgb_lf_group@blacksheep.org X-Listname: rsgb_lf_group Sender: Good evening Wolf & All > The 7 MHz signal suffers from multipath, every Jason symbol (tone) now > consists of two peaks separated 50..150 mHz (m=milli, M=Mega, the European > way). > The decoder doesn't like it, but on a waterfall it looks interesting (like > ancient symbols..). This is interesting. 100 mHz doppler shift at 7 MHz corresponds to a speed of 3e8*0.1/7e6 = 4.3 m/s (neglecting relativistic stuff :-). This is the speed at which the two (assuming two) path lengths differ. At this short distance it is almost NVIS propagation. Could it be two reflecting layers that move vertically with respect to each other when the sun sets? 73 Johan SM6LKM