Return-Path: Received: from post.thorcom.com (post.thorcom.com [195.171.43.25]) by klubnl.pl (8.14.4/8.14.4/Debian-8+deb8u2) with ESMTP id vBUBvcTI014093 for ; Sat, 30 Dec 2017 12:57:39 +0100 Received: from majordom by post.thorcom.com with local (Exim 4.14) id 1eVFft-0003E5-So for rs_out_1@blacksheep.org; Sat, 30 Dec 2017 11:51:37 +0000 Received: from [195.171.43.32] (helo=relay1.thorcom.net) by post.thorcom.com with esmtp (Exim 4.14) id 1eVFfm-0003Dw-7x for rsgb_lf_group@blacksheep.org; Sat, 30 Dec 2017 11:51:30 +0000 Received: from omr-m010e.mx.aol.com ([204.29.186.10]) by relay1.thorcom.net with esmtps (TLSv1:DHE-RSA-AES256-SHA:256) (Exim 4.89) (envelope-from ) id 1eVFfi-0007T3-FD for rsgb_lf_group@blacksheep.org; Sat, 30 Dec 2017 11:51:28 +0000 Received: from mtaomg-aae02.mx.aol.com (mtaomg-aae02.mx.aol.com [172.27.1.100]) by omr-m010e.mx.aol.com (Outbound Mail Relay) with ESMTP id 4E7773800084 for ; Sat, 30 Dec 2017 06:51:22 -0500 (EST) Received: from core-acx10e.mail.aol.com (core-acx10.mail.aol.com [172.27.155.135]) by mtaomg-aae02.mx.aol.com (OMAG/Core Interface) with ESMTP id D0A6F38000081 for ; Sat, 30 Dec 2017 06:51:21 -0500 (EST) Received: from 188.194.222.230 by webjas-vac077.srv.aolmail.net (10.96.19.80) with HTTP (WebMailUI); Sat, 30 Dec 2017 06:51:21 -0500 Date: Sat, 30 Dec 2017 06:51:21 -0500 From: Markus Vester To: rsgb_lf_group@blacksheep.org Message-Id: <160a7431cfd-171d-50ee@webjas-vac077.srv.aolmail.net> In-Reply-To: <29b0445b-bcb6-fc3c-add0-cbba03ad693a@abelian.org> MIME-Version: 1.0 X-MB-Message-Source: WebUI X-MB-Message-Type: User X-Mailer: JAS STD X-Originating-IP: [188.194.222.230] x-aol-global-disposition: G DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mx.aol.com; s=20150623; t=1514634682; bh=Io5N0hLIjhHNmWXHm5rp4Dm872HIUXbJ1B7IMdQcihw=; h=From:To:Subject:Message-Id:Date:MIME-Version:Content-Type; b=qc7V97W1h1vZJ+hzlkQcw9La0ndxn9VIRkUeZZpzcS5uc+2zxSy49GJgzOqhhcFYd BBfVb0Az2+y/hPKPkydM151vieL/Qz31JrZ19biq3jVJtbLxnzlGdD4Y0lFVFEy65W YxBUFV+5YLCYmxm3dq5WEh0QVFQ2UTdx2ls/pV30= x-aol-sid: 3039ac1b01645a477db92897 X-Spam-Score: 0.0 (/) X-Spam-Report: Spam detection software, running on the system "relay1.thorcom.net", has NOT identified this incoming email as spam. The original message has been attached to this so you can view it or label similar future email. If you have any questions, see the administrator of that system for details. Content preview: Let's say station A (e.g. Dex) is transmitting, receiver B (e.g. Paul) knows the message (no matter if by a local decode or by some other means), and receiver C (e.g. Alex) is trying to achieve a decode, assisted by information from B. As a guideline for possible rules, I would propose the following: Assume that C has not received any energy from A. Then information from B should not eventually lead to a false positive decode at C, not even increase it's probability. [...] Content analysis details: (0.0 points, 5.0 required) pts rule name description ---- ---------------------- -------------------------------------------------- 0.0 FREEMAIL_FROM Sender email is commonly abused enduser mail provider (markusvester[at]aol.com) -0.0 T_RP_MATCHES_RCVD Envelope sender domain matches handover relay domain 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: 96c1546db5321e0e52b4c66d17932f07 Subject: Re: LF: 8269.9 kHz EbNaut 27/12/17 - decoding ethics? Content-Type: multipart/alternative; boundary="----=_Part_26249_995114732.1514634681597" X-Spam-Checker-Version: SpamAssassin 2.63 (2004-01-11) on post.thorcom.com X-Spam-Level: ** X-Spam-Status: No, hits=2.1 required=5.0 tests=HTML_MESSAGE, MAILTO_TO_SPAM_ADDR,NO_COST 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 ------=_Part_26249_995114732.1514634681597 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Let's say station A (e.g. Dex) is transmitting, receiver B (e.g. Paul) know= s the message (no matter if by a local decode or by some other means), and = receiver C (e.g. Alex) is trying to achieve a decode, assisted by informati= on from B. As a guideline for possible rules, I would propose the following= : Assume that C has not received any energy from A. Then information from B= should not eventually lead to a false positive decode at C, not even incre= ase it's probability. > So, do ethics accept a decode claim if it is necessary to use published i= nformation about the transmit phase to facilitate stacking? Clearly yes. As you say, information from B describes a property of A's tr= ansmitter (e.g. the accurate frequency), which is not related to message co= ntent. > And what about using information published from other sites about the str= ength and success of the transmission? Obviously yes, if it's related tro transmitter itself (e.g low tx antenna c= urrent, aborted transmissions etc. during certain nights). In my opinion, this should also extended to propagation-related information= (e.g. the phase change between A and B due to transversing the Atlantic). = That is more or less equivalent to using other available data for propagati= on estimates (like Navy-MSK magnitude and phase, electron content, solar da= ta), which is "legal". > Pushing this further, once the message is published, the repeats can be s= elected for stacking based on their cross-correlation.=20 Accorduing to the "guideline", neither B or C may make use of the actual no= ise instance at receiver C to preselect C's data, because that could bias t= he noise statistics at C towards a decode. So the knowledge of A's message = and C's noise should not be combined. Clearly, C may not apply knowledge of= the message to make correlations with his own noise, and use them to weigh= t or preselect his data.=20 On the other hand, in my opinion correlation results from B (based on propa= gation A-B and noise at B) could "legally" be used for stacking by C. This = implicitly assumes that noise instances at B or C are uncorrelated, so appl= ying B's weights at C won't bias C's noise towards the correct message. Howecver theoretically the noise at B and C could be correlated, for exampl= e if the dominant noise source is a very localized thunderstorm, affecting = both B and C. Then B has indirect access to noise at C, and application of = B's correlation results could bias C's noise statistics. Depending on phase= differences, this could increase or decrease the likelyhood of a correct d= ecode at C. In practice, given the size and movement of thunderstorms acomp= ared to the wavelength, I would not expect a large noise correlation betwee= n far-spaced receiver sites (unless for certain special geometries, e.g. al= l three stations and noise sources arranged in-line on the same great-circl= e). Thus in my opinion, the application of B's correlations at C should not= be generally forbidden.=20 So like with many questions in ethics, the answers are not always purely bl= ack or white. I have to say I'm glad Ive become an engineer rather than a l= awyer ;-) Best 73, Markus (DF6NM) -----Urspr=C3=BCngliche Mitteilung-----=20 Von: Paul Nicholson An: rsgb_lf_group Verschickt: Fr, 29. Dez 2017 19:29 Betreff: Re: LF: 8269.9 kHz EbNaut 27/12/17 Dex wrote: > New message tonight [27th] > 3 chars 16K21A CRC20 > 30 second symbols > Start 22:30 UT Decoding from 8269.9 Hz, 2017-12-XX_22:30,+27900 vtfilter -h bp,f=3D8270,w=3D3000 vtblank -a12 -d0 -t100 ebnaut -dp16K21A -r1 -S30 -k20 -N3 -PU -L500000 -v Todmorden (6194 km) ------------------- 27/28 Eb/N0 +9.2 dB, S/N -22.9 dB/1Hz, phase -140.9 *Decoded* 28/29 Eb/N0 +5.4 dB, S/N -26.7 dB/1Hz, phase 108.7 *Decoded* Bielefeld (6917.7 km) --------------------- 27/28 Eb/N0 -2.6 dB, S/N -34.7 dB/1Hz, phase 71.2; 28/29 Eb/N0 -2.3 dB, S/N -34.4 dB/1Hz, phase -45.2; Fails to decode with stacking, Eb/N0 -5.0 dB due to phase change. Warsaw (7681.3 km) ------------------ 27/28 Eb/N0 -7.4 dB, S/N -39.6 dB/1Hz, phase 143.3; 28/29 Eb/N0 -11.5 dB, S/N -43.7 dB/1Hz, phase 85.6; Cumiana (7173.4 km) ------------------- 27/28 Eb/N0 +0.6 dB, S/N -31.6 dB/1Hz, phase 164.1 *Decoded* 28/29 Eb/N0 -2.1 dB, S/N -34.2 dB/1Hz, phase 63.2; Hawley TX (1816.2 km) --------------------- 27/28 Eb/N0 7.8 dB, S/N -24.3 dB/1Hz, phase -86.3 *Decoded* 28/29 Eb/N0 1.3 dB, S/N -30.8 dB/1Hz, phase -163.5 *Decoded* Forest VA (254.2 km) -------------------- 27/28 Eb/N0 21.2 dB, S/N -10.8 dB/1Hz, phase 115.9 *Decoded* 28/29 Eb/N0 20.4 dB, S/N -11.8 dB/1Hz, phase -14.0 *Decoded* All the rx sites show a similar phase change between the two nights, even Warsaw with the very weak signal. So, do ethics accept a decode claim if it is necessary to use published information about the transmit phase to facilitate stacking? One might argue that knowledge of the tx phase is no different to knowing the tx frequency and start time. Such knowledge does not bypass any propagation. And what about using information published from other sites about the strength and success of the transmission? A problem with stacking is the number of permutations as the number of repeats increases. Eg with four repeats, there are: One run with all four; Four runs with one repeat dropped; Six runs with two repeats dropped; Four runs with single repeats; 15 runs altogether and the operator is obliged to accept the strongest looking decode out of all of them. Each of the 15 runs has the chance of throwing up a false decode which will beat the correct decode. Therefore, knowledge that a particular repeat performed poorly at other sites allows you to drop that one with no cost in terms of false decodes. Pushing this further, once the message is published, the repeats can be selected for stacking based on their cross- correlation. You might for example have 10 repeats and be able to get a decode from the best 5, Without that knowledge you would need 252 full runs of the decoder to go through all permutations of 5 out of 10 repeats, surely enough to suffer a stronger false decode. -- Paul Nicholson -- ------=_Part_26249_995114732.1514634681597 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Let's say station A (e.g. Dex) is transmitting= , receiver B (e.g. Paul) knows the message (no matter if by&= nbsp;a local decode or by some other means), and receiver C (e.g. Alex) is = trying to achieve a decode, assisted by information from B. As a guide= line for possible rules, I would propose the following: Assume that C has n= ot received any energy from A. Then information from B should not even= tually lead to a false positive decode at C, not even increase it's probabi= lity.

> So, do ethics accept a decode claim if it is necessary to= use published information about the transmit phase to facilitate stacking?=

Clearly yes. As you say, information from B describes a property of=   A's transmitter (e.g. the accurate frequency), which is no= t related to message content.

> And what about using information = published from other sites about the strength and success of the transmissi= on?

Obviously yes, if it's related tro transmitter itself (e.g low t= x antenna current, aborted transmissions etc. during certain nights).
In my opinion, this should also extended to propagation-re= lated information (e.g. the phase change between A and B due to transv= ersing the Atlantic). That is more or less equivalent to using other a= vailable data for propagation estimates (like Navy-MSK magnitude and phase,= electron content, solar data), which is "legal".

> Pushing this = further, once the message is published, the repeats can be selected for sta= cking based on their cross-correlation.

Accorduing to the "guidelin= e", neither B or C may make use of the actual noise instance at r= eceiver C to preselect C's data, because that could bias the noise sta= tistics at C towards a decode. So the knowledge of A's message and C's nois= e should not be combined. Clearly, C may not apply knowledge of the message= to make correlations with his own noise, and use them to&nb= sp;weight or preselect his data. 

On the other hand, in my= opinion correlation results from B (based on propagation A-B and noise at = B) could "legally" be used for stacking by C. This implicitly ass= umes that noise instances at B or C are uncorrelated, so applying B's = weights at C won't bias C's noise towards the correct message.

= Howecver theoretically the noise at B and C could be correla= ted, for example if the dominant noise source is a very localized= thunderstorm, affecting both B and C. Then B has indirect access to n= oise at C, and application of B's correlation results could bias = C's noise statistics. Depending on phase differences, this could incre= ase or decrease the likelyhood of a correct decode at C. In practice, = given the size and movement of thunderstorms acompared to the wavelength, I=  would not expect a large noise correlation between far-spaced receive= r sites (unless for certain special geometries, e.g. all three stations&nbs= p;and noise sources arranged in-line on the same great-circle). Thus in my = opinion, the application of B's correlations at C should not be generally f= orbidden.

So like with many questions in ethics, the answers a= re not always purely black or white. I have to say I'm glad Ive become= an engineer rather than a lawyer ;-)

Best 73,
Markus (DF6NM= )

-----Urspr=C3=BCngliche Mitteilung-----
Von: Paul Nicholson &l= t;vlf0403@abelian.org>
An: rsgb_lf_group <rsgb_lf_group@blacksheep= .org>
Verschickt: Fr, 29. Dez 2017 19:29
Betreff: Re: LF: 8269.9 k= Hz EbNaut 27/12/17

Dex wrote:

> New message tonight= [27th]

> 3 chars 16K21A CRC20
> 30 second symbols
&g= t; Start 22:30 UT

Decoding from 8269.9 Hz, 2017-12-XX_22:30,+27900vtfilter -h bp,f=3D8270,w=3D3000
vtblank -a12 -d0 -t100
ebnaut -dp1= 6K21A -r1 -S30 -k20 -N3 -PU -L500000 -v

Todmorden (6194 km)
-----= --------------

27/28 Eb/N0 +9.2 dB, S/N -22.9 dB/1Hz, phase -140.9= *Decoded*
28/29 Eb/N0 +5.4 dB, S/N -26.7 dB/1Hz, phase 108.7 *Decode= d*

Bielefeld (6917.7 km)
---------------------

27/28 Eb/= N0 -2.6 dB, S/N -34.7 dB/1Hz, phase 71.2;
28/29 Eb/N0 -2.3 dB, S/N -3= 4.4 dB/1Hz, phase -45.2;

Fails to decode with stacking, Eb/N0 -5.0= dB due to
phase change.

Warsaw (7681.3 km)
----------------= --

27/28 Eb/N0 -7.4 dB, S/N -39.6 dB/1Hz, phase 143.3;
28/29= Eb/N0 -11.5 dB, S/N -43.7 dB/1Hz, phase 85.6;

Cumiana (7173.4 km)<= br>-------------------

27/28 Eb/N0 +0.6 dB, S/N -31.6 dB/1Hz, phas= e 164.1 *Decoded*
28/29 Eb/N0 -2.1 dB, S/N -34.2 dB/1Hz, phase 63.2;<= br>
Hawley TX (1816.2 km)
---------------------

27/28 Eb/N0 = 7.8 dB, S/N -24.3 dB/1Hz, phase -86.3 *Decoded*
28/29 Eb/N0 1.3 dB, S= /N -30.8 dB/1Hz, phase -163.5 *Decoded*

Forest VA (254.2 km)
----= ----------------

27/28 Eb/N0 21.2 dB, S/N -10.8 dB/1Hz, phase 115.= 9 *Decoded*
28/29 Eb/N0 20.4 dB, S/N -11.8 dB/1Hz, phase -14.0 *Decode= d*

All the rx sites show a similar phase change between the two
n= ights, even Warsaw with the very weak signal.

So, do ethics accept a= decode claim if it is necessary to use
published information about the = transmit phase to facilitate
stacking?

One might argue that knowl= edge of the tx phase is no different
to knowing the tx frequency and sta= rt time. Such knowledge
does not bypass any propagation.

And wha= t about using information published from other sites
about the strength = and success of the transmission?

A problem with stacking is the numb= er of permutations as the
number of repeats increases. Eg with four rep= eats, there are:

One run with all four;
Four runs with one re= peat dropped;
Six runs with two repeats dropped;
Four runs with s= ingle repeats;

15 runs altogether and the operator is obliged to acc= ept the
strongest looking decode out of all of them. Each of the
15 = runs has the chance of throwing up a false decode which
will beat the co= rrect decode. Therefore, knowledge that a
particular repeat performed p= oorly at other sites allows you
to drop that one with no cost in terms o= f false decodes.

Pushing this further, once the message is published= , the
repeats can be selected for stacking based on their cross-
corr= elation. You might for example have 10 repeats and be
able to get a dec= ode from the best 5, Without that knowledge
you would need 252 full run= s of the decoder to go through all
permutations of 5 out of 10 repeats, = surely enough to suffer
a stronger false decode.

--
Paul Nicho= lson
--

------=_Part_26249_995114732.1514634681597--