Delivered-To: daveyxm@virginmedia.com Received: by 10.50.237.98 with SMTP id vb2csp101281igc; Mon, 10 Mar 2014 04:36:45 -0700 (PDT) X-Received: by 10.194.109.68 with SMTP id hq4mr30874667wjb.12.1394451405354; Mon, 10 Mar 2014 04:36:45 -0700 (PDT) Return-Path: Received: from post.thorcom.com (post.thorcom.com. [195.171.43.25]) by mx.google.com with ESMTP id kq9si1628009wjc.17.2014.03.10.04.36.44 for ; Mon, 10 Mar 2014 04:36:45 -0700 (PDT) Received-SPF: neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) client-ip=195.171.43.25; Authentication-Results: mx.google.com; spf=neutral (google.com: 195.171.43.25 is neither permitted nor denied by best guess record for domain of owner-rsgb_lf_group@blacksheep.org) smtp.mail=owner-rsgb_lf_group@blacksheep.org; dkim=fail (test mode) header.i=@btinternet.com Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1WMxxe-0000dp-Ij for rs_out_1@blacksheep.org; Mon, 10 Mar 2014 11:01:34 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1WMxxd-0000dg-Kr for rsgb_lf_group@blacksheep.org; Mon, 10 Mar 2014 11:01:33 +0000 Received: from smtpout17.bt.lon5.cpcloud.co.uk ([65.20.0.137]) by relay1.thorcom.net with esmtp (Exim 4.82) (envelope-from ) id 1WMxxa-0005A6-E9 for rsgb_lf_group@blacksheep.org; Mon, 10 Mar 2014 11:01:32 +0000 X-CTCH-RefID: str=0001.0A090209.531D9B87.030D,ss=1,re=0.000,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-Junkmail-Premium-Raw: score=13/97,refid=2.7.2:2014.3.10.70015:17:13.296,ip=,rules=__HAS_MSGID, __SANE_MSGID, MSGID_32HEX_LC, INVALID_MSGID_NO_FQDN, __MSGID_32HEX, __HAS_FROM, __PHISH_FROM2, __FRAUD_WEBMAIL_FROM, __TO_MALFORMED_2, __TO_NO_NAME, LEO_OBFU_SUBJ_RE, __BOUNCE_CHALLENGE_SUBJ, __BOUNCE_NDR_SUBJ_EXEMPT, __SUBJ_ALPHA_END, __MIME_VERSION, __CT, __CTYPE_MULTIPART_ALT, __CTYPE_HAS_BOUNDARY, __CTYPE_MULTIPART, __HAS_X_PRIORITY, __HAS_MSMAIL_PRI, __HAS_X_MAILER, USER_AGENT_OE, __OUTLOOK_MUA_1, __USER_AGENT_MS_GENERIC, __ANY_URI, IP_HTTP_ADDR_WITH_PORT, __CP_URI_IN_BODY, __STOCK_PHRASE_7, __SUBJ_ALPHA_NEGATE, SUPERLONG_LINE, __HTML_FONT_BLUE, __HAS_HTML, BODY_SIZE_10000_PLUS, __MIME_HTML, __TAG_EXISTS_HTML, __STYLE_RATWARE_NEG, __URI_NS, HTML_50_70, __PHISH_FROM, __OUTLOOK_MUA, __FRAUD_WEBMAIL, FORGED_MUA_OUTLOOK X-CTCH-Spam: Unknown Received: from gnat (86.178.175.13) by smtpout17.bt.lon5.cpcloud.co.uk (8.6.100.99.10223) (authenticated as alan.melia@btinternet.com) id 5318507B0045A914 for rsgb_lf_group@blacksheep.org; Mon, 10 Mar 2014 11:01:28 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=btinternet.com; s=btcpcloud; t=1394449291; bh=hOaXNyNZui+wH4uNR9K1dFU/0RDDWJAgW6Y5+miqpMY=; h=Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Mailer; b=JD54q5GGTRSJuVWPelW0LGUX23MJYdXDjSbupMOV2hreKnYMZoV1zBFn/5iAsZYVt0rW/osKGe5OaSPapB8ZFKwUzpLmrKi+T3l1ZOVmq7YI11b5T/MQ4/MaMy92SN/NAZx+2L7Ac3WCBO6+IZCyaR+vQCIZeD5qftBvZl0uHSI= Message-ID: From: "Alan Melia" To: References: <048001cf3c01$e513fd00$af3bf700$@comcast.net> Date: Mon, 10 Mar 2014 11:01:06 -0000 MIME-Version: 1.0 X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5931 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has identified this incoming email as possible spam. The original message has been attached to this so you can view it (if it isn't spam) or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Hi Jim we see this sort of effect in the UK no doubt Paul has seen it on his plots. There are a number of observer of SIDs using the Military stations in Eu. Often stations only about 50 miles apart will get radically different "patterns" I have often seen night-time levels less than daytime levels, Dome shapes at noon in daytime and inverted "domes". Most of these have been within range of significant ground wave, which I think seems to give the most radical differences. At longer range say over 1500km the main interaction seems to be between different modes sau two hop and 3 hop in ray tracing parlance. Of course both of these change phase with changes in the ionosphere. At shorter ranges the main constituent is groundwave and this is sensibly constant day-night. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 NORMAL_HTTP_TO_IP URI: Uses a dotted-decimal IP address in URL 0.0 HTML_MESSAGE BODY: HTML included in message 0.0 T_DKIM_INVALID DKIM-Signature header exists but is not valid X-Scan-Signature: 75d539362fc79d60c5509fd0caf011e8 Subject: LF: Re: Interesting Data Content-Type: multipart/alternative; boundary="----=_NextPart_000_0021_01CF3C50.091ADF40" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.3 required=5.0 tests=FORGED_MUA_OUTLOOK,HTML_40_50, HTML_MESSAGE,NORMAL_HTTP_TO_IP autolearn=no version=2.63 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 This is a multi-part message in MIME format. ------=_NextPart_000_0021_01CF3C50.091ADF40 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Hi Jim we see this sort of effect in the UK no doubt Paul has seen it on = his plots. There are a number of observer of SIDs using the Military = stations in Eu. Often stations only about 50 miles apart will get = radically different "patterns" I have often seen night-time levels less = than daytime levels, Dome shapes at noon in daytime and inverted = "domes". Most of these have been within range of significant ground = wave, which I think seems to give the most radical differences. At = longer range say over 1500km the main interaction seems to be between = different modes sau two hop and 3 hop in ray tracing parlance. Of course = both of these change phase with changes in the ionosphere. At shorter = ranges the main constituent is groundwave and this is sensibly constant = day-night. One observer took data at fairly short distance (100-120 miles I think) = from two relatively close transmitters (Anthorn and Skelton) and uses = the data to calculate the apparent reflection height, then did a = least-squares fit on the data, adding ground wave one hop and two hop. = He managed some quite sensible results, bearing in mind the simplicity = and some of the assumptions (2-hop reflection at same apparent height as = 1-hop etc) I think this is writen up in the Radio Astronomy Group web = site.=20 Alan G3NYK ----- Original Message -----=20 From: hvanesce=20 To: rsgb_lf_group@blacksheep.org=20 Sent: Monday, March 10, 2014 1:41 AM Subject: LF: Interesting Data = http://59.160.210.74:8080/jspui/bitstream/123456789/454/1/VLF%20signals%2= 0in%20summer.pdf (Bose National Centre for Basic Sciences) http://www.ursi.org/proceedings/procGA11/ursi/GP2-15.pdf =20 =20 Paul, =20 I'm sending this link because the data seems unusual. I thought it = might come in handy if something of this sort appears in efforts within = this group; but I am not inclined to have confidence in the results of = the attached unless I happen to run across similar independent results = (and I did not, in my search last week). So, I'm planning to just file = the attached but thought you might want to see it because it's = interesting if not well-supported by other studies.=20 =20 Plots* in the link below show an interesting distribution of VLF broad = daytime amplitude maxima that are (a) greater than, or (b) less than = nighttime maxima. =20 The study used a single transmitter (18.2 kHz), and receivers at = distances from 500 km to ~ 3,000 km, with two-week collections in summer = and winter. =20 I tried to correlate (a) or (b) (daytime maxima greater than or less = than nighttime maxima) with distance or bearing and did not find a = reasonable correlation. =20 In winter 3 of 9 RX stations had daytime amplitude (broad) maxima = greater than nighttime maxima. In summer 3 of 12 RX stations had daytime amplitude (broad) maxima = greater than nighttime maxima. =20 Winter "day maximum minus night maximum" (averaged over 2 weeks) = ranged (by RX station) from +20 dB to -11 dB, with 6 of 9 RX stations on = the - side; the winter average of all RX stations seemed to be around = -0.5 dB Summer "day maximum minus night maximum" (averaged over 2 weeks) = ranged (by RX station) from +8 dB to -10 dB, with 9 of 12 RX stations on = the - side; the summer average of all RX stations seemed to be around -2 = dB =20 The wide range of "day maximum minus night maximum" results (by RX = station), together with the absence of any apparent correlation with = distance or bearing, makes this data seem unusual. Well, maybe not for = LF/VLF. =20 =20 * Figure 3 and Figure 7 =20 73, Jim AA5BW ------=_NextPart_000_0021_01CF3C50.091ADF40 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Hi Jim we see this sort of effect in = the UK no=20 doubt Paul has seen it on his plots. There are a number of observer of = SIDs=20 using the Military stations in Eu. Often stations only about 50 miles = apart will=20 get radically different "patterns" I have often seen night-time levels = less than=20 daytime levels, Dome shapes at noon in daytime and inverted "domes". = Most of=20 these have been within range of significant ground wave, which I think = seems to=20 give the most radical differences. At longer range say over 1500km the = main=20 interaction seems to be between different modes sau two hop and 3 hop in = ray=20 tracing parlance. Of course both of these change phase with changes in = the=20 ionosphere. At shorter ranges the main constituent is groundwave and = this is=20 sensibly constant day-night.
 
One observer took data at fairly short = distance=20 (100-120 miles I think) from two relatively close transmitters (Anthorn = and=20 Skelton) and uses the data to calculate the apparent reflection height, = then did=20 a least-squares fit on the data, adding ground wave one hop and two hop. = He=20 managed some quite sensible results, bearing in mind the simplicity and = some of=20 the assumptions (2-hop reflection at same apparent height as 1-hop etc) = I think=20 this is writen up in the Radio Astronomy Group web = site. 
 
Alan G3NYK
 
 
----- Original Message -----
From:=20 hvanesce=20
Sent: Monday, March 10, 2014 = 1:41=20 AM
Subject: LF: Interesting = Data

http://59.160.210.74:8080/jspui/bitstream/12345= 6789/454/1/VLF%20signals%20in%20summer.pdf=20 (Bose National Centre for Basic Sciences)

http://= www.ursi.org/proceedings/procGA11/ursi/GP2-15.pdf

 

 

Paul,

 

I=92m = sending this=20 link because the data seems unusual. I thought it might come in handy = if=20 something of this sort appears in efforts within this group; but I am = not=20 inclined to have confidence in the results of the attached unless I = happen to=20 run across similar independent results (and I did not, in my search = last=20 week). So, I=92m planning to just file the attached but thought you = might want=20 to see it because it=92s interesting if not well-supported by other = studies.=20

 

Plots* in = the link=20 below show an interesting distribution of VLF broad daytime amplitude = maxima=20 that are (a) greater than, or (b) less than nighttime=20 maxima.

 

The study = used a=20 single transmitter (18.2 kHz), and receivers at distances from 500 km = to ~=20 3,000 km, with two-week collections in summer and=20 winter.

 

I tried to = correlate=20 (a) or (b) (daytime maxima greater than or less than nighttime maxima) = with=20 distance or bearing and did not find a reasonable=20 correlation.

 

In winter = 3 of 9 RX=20 stations had daytime amplitude (broad) maxima greater than nighttime=20 maxima.

In summer = 3 of 12 RX=20 stations had daytime amplitude (broad) maxima greater than nighttime=20 maxima.

 

Winter = =93day maximum=20 minus night maximum=94 (averaged over 2 weeks) ranged (by RX station) = from +20=20 dB to -11 dB, with 6 of 9 RX stations on the - side; the winter = average of all=20 RX stations seemed to be around -0.5 dB

Summer = =93day maximum=20 minus night maximum=94 (averaged over 2 weeks) ranged (by RX station) = from +8 dB=20 to -10 dB, with 9 of 12 RX stations on the - side; the summer average = of all=20 RX stations seemed to be around -2 dB

 

The wide = range of=20 =93day maximum minus night maximum=94 results (by RX station), = together with the=20 absence of any apparent correlation with distance or bearing, makes = this data=20 seem unusual. Well, maybe not for LF/VLF.

 

 

* Figure 3 = and=20 Figure 7

 

73,  = Jim=20 AA5BW

------=_NextPart_000_0021_01CF3C50.091ADF40--