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REU - DSC Logs from Ariano Irpino, South Italy

ros.palermo@...
 

Report from      :Rosario Palermo iz8294swl

QTH                  :Ariano Irpino, AV, Italy

Locators           :41°08'01.8"N 15°04'54.3"E

Receiever(s)     :SDRplay RSP1A / JRC NDR 525 /R1000

Antenna(s)        :genuine PA0RDT MiniWhip at 4m / dipole 30 mt

Decoder           :Yadd 1.7.1



Hi all,
Recent DSC logs.

A mistake?
Please help me.

20190723 1939  2187.5 002734412 Vladivostok Radio, RUS, 8821 Km

RX:2187.5
SYMB: 120 120 027 033 057 065 000 108 000 027 034 041 026 118 126 ~~~ 126 ~~~ 126 126 126 ~~~ ~~~ 040 ~~~
FMT:SEL  CAT:SAF TO:SHIP,273357650,GELIUS 1,UGIA,Cargo FR:COAST,002734412,RUS,Vladivostok Radio
TC1:TEST  TC2:NOINF  FREQ:--  POS: -- EOS: UNK/ERR ECC: 84 ERR


20190723 1823  2187.5 002371000 Olympia Radio, GRC, 674 Km
20190723 1902  2187.5 002070810 Varna Radio, BUL, 1071 Km
20190723 1927  2187.5 002470124 Crotone Radio, I, 285 Km
20190723 2010  2187.5 002241024 Valencia Radio, E, 1412 Km
20190723 2025  2187.5 002241022 Coruna Radio, E, 1904 Km
20190723 2123  2187.5 002711000 Istanbul Radio, TUR, 1154 Km
20190723 2129  2187.5 002734411 Novorossiysk Radio, RUS, 1889 Km
20190723 2132  2187.5 002610210 Witowo Radio, POL, 1492 Km
20190723 2133  2187.5 002734487 Taganrog Radio, RUS, 1966 Km
20190723 2154  2187.5 002715000 Izmir Radio, TUR, 1032 Km
20190723 2156  2187.5 002712000 Samsun Radio, TUR, 1778 Km
20190723 2156  2187.5 002275200 CROSS Jobourg, F, 1629 Km
20190723 2158  2187.5 002734414 Arkhangelsk Radio, RUS, 3064 Km
20190723 2158  2187.5 002713000 Antalya Radio, TUR, 1429 Km
20190723 2221  2187.5 002442000 Netherlands CG Radio, HOL, 1475 Km
20190723 2222  2187.5 002191000 Lyngby Radio, DNK, 1687 Km
20190723 2223  2187.5 002653000 Goteborg Radio, S, 1836 Km
20190723 2235  2187.5 002241026 Las Palmas Radio, E, 3083 Km
20190723 2240  2187.5 002470002 Palermo Radio, I, 365 Km
20190723 2244  2187.5 002320010 Dover Coastguard, G, -- Km
20190723 2244  2187.5 002320001 Shetland Coastguard, G, 2438 Km
20190723 2302  2187.5 002733700 Saint Petersburg Radio, RUS, 2315 Km
20190723 2329  2187.5 002570300 Rogaland Radio, NOR, 2064 Km
20190724 0017  2187.5 002470128 Mazara del Vallo Radio, I, 438 Km
20190724 0018  2187.5 002320018 Holyhead Coastguard, G, 2007 Km
20190724 0033  2187.5 002320021 Belfast Coastguard, G, 2330 Km
20190724 0050  2187.5 002652000 Stockholm Radio, S, 1603 Km
20190724 0051  2187.5 002570000 Public Correspondence, NOR, -- Km
20190724 0143  2187.5 002570500 Floroe Radio, NOR, 2379 Km
20190724 0152  2187.5 002320007 Humber Coastguard, G, 1972 Km
20190724 0206  2187.5 002320004 Aberdeen Coastguard, G, 2165 Km
20190724 0507  2187.5 002470125 Genova Radio, I, 624 Km


20190723 1616  6312.0 002371000 Olympia Radio, GRC, 674 Km
20190723 1702  6312.0 005671000 Bangkok Radio, THA, 8652 Km

20190723 1602  8414.5 002711000 Istanbul Radio, TUR, 1154 Km
20190723 1605  8414.5 005671000 Bangkok Radio, THA, 8652 Km
20190723 1621  8414.5 004122100 Shanghai Radio, CHN, 9016 Km
20190723 1659  8414.5 005741040 Hai Phong Radio, VTN, 8593 Km
20190723 1718  8414.5 002371000 Olympia Radio, GRC, 674 Km
20190723 1812  8414.5 004122100 Shanghai Radio, CHN, 9016 Km
20190723 1824  8414.5 002241022 Coruna Radio, E, 1904 Km
20190723 1905  8414.5 005671000 Bangkok Radio, THA, 8652 Km
20190723 2013  8414.5 002371000 Olympia Radio, GRC, 674 Km
20190723 2024  8414.5 006221111 Alexandria Radio, EGY, 1725 Km
20190724 0411  8414.5 002070810 Varna Radio, BUL, 1071 Km

73,Rosario


Jay Law
 

On Wed, Jul 24, 2019 at 11:11 AM, <ros.palermo@...> wrote:


20190723 1939  2187.5 002734412 Vladivostok Radio, RUS, 8821 Km

RX:2187.5
SYMB: 120 120 027 033 057 065 000 108 000 027 034 041 026 118 126 ~~~ 126 ~~~ 126 126 126 ~~~ ~~~ 040 ~~~
FMT:SEL  CAT:SAF TO:SHIP,273357650,GELIUS 1,UGIA,Cargo FR:COAST,002734412,RUS,Vladivostok Radio
TC1:TEST  TC2:NOINF  FREQ:--  POS: -- EOS: UNK/ERR ECC: 84 ERR


Hi Ros

My guess (!) is the 026 is an error as it should always end in a zero....Peter?
 
--
Best Regards & Good DX

Jay

peter
 

On 24/07/2019 11:39, Jay Law wrote:
On Wed, Jul 24, 2019 at 11:11 AM, <ros.palermo@...> wrote:



20190723 1939  2187.5 002734412 *Vladivostok Radio* , RUS, 8821 Km

RX:2187.5
SYMB: 120 120 027 033 057 065 000 108 000 027 034 041 *026* 118 126 ~~~ 126
~~~ 126 126 126 ~~~ ~~~ 040 ~~~
FMT:SEL  CAT:SAF TO:SHIP,273357650,GELIUS 1,UGIA,Cargo
FR:COAST,002734412,RUS,Vladivostok Radio
TC1:TEST  TC2:NOINF  FREQ:--  POS: -- EOS: UNK/ERR ECC: 84 ERR

*
*
Hi Ros

My guess (!) is the *026* is an error as it should always end in a zero....Peter?

--
Best Regards & Good DX

Jay

Hi Rosario & Jay,
I tend to agree with Jay though my knowledge on the *026* is poor - but the message was signed as an *ERR* I have nothing logged here at that time relevant.  Maybe John can explain more..

73, Peter

Jay Law
 

Rosario

Is there a corresponding message from the ship station addressed to Vladivostock...?
You have an ID for the ship station - what is it's present position ie Sea of Japan / East China Sea area.... on 2 MHz it is likely to be fairly close to the coast station?

You can enter the MMSI of the ship into marinetraffic.com...

If its in that area, and assuming the rest of the MMSI is correct, the only other RSE station in the East is 002734421 Vanino Radio.

As Peter says, there are lots of errors (and assumptions)!

All good stuff - I like to investigate...even if it comes to nothing
--
Best Regards & Good DX

Jay

John Pumford-Green
 

On 24/07/2019 14:15, peter via Groups.Io wrote:

Hi Rosario & Jay,
I tend to agree with Jay though my knowledge on the *026* is poor - but the message was signed as an *ERR* I have nothing logged here at that time relevant.  Maybe John can explain more..
73, Peter

I agree that there's at least one error in the message - the ECC check fails - hence the "ECC: 84 ERR"

Looking at YaDDNet I see that there's a message from Novorossiysk Radio, 002734411 at the same time as Rosario's report of "Vladivistok", addressed to the same vessel, and received without ECC errors by Frikko Nuijen (NL8811):


Input : [NL8811];2187.5;SEL;273357650;SAF;002734411;TEST;NOINF;--;--;ACK;ECC 62 OK
Time : 2019-07-23 19:39:12
Monitor : NL8811
Frequency : 2187.5 kHz
Format : SEL
To : SHIP 273357650 : GELIUS 1, UGIA, Cargo : Russia
Category : SAF
From : COAST 002734411 : Novorossiysk Radio : Russia
Tele 1 : TEST
Tele 2 : NOINF
Freq : --
Pos : --
EOS : ACK
ECC : OK


Rosario's message is almost certainly the same one, from Novorossiysk.

The correct symbols for the "real" message would have been:

120 120 027 033 057 065 000 108 000 027 034 041 010 118 126 126 126
126 126 126 126 122 062 122 122

The "062" is the transmitted ECC character, obtained by XORing together the message symbols:

"120 027 033 057 065 000 108 000 027 034 041 010 118 126 126 126 126 126 126 126 122"


Compare this to Rosario's message:

120 120 027 033 057 065 000 108 000 027 034 041 *026* 118 126 ~~~ 126
~~~ 126 126 126 ~~~ ~~~ 040 ~~~

His message shows that YaDD calculated an ECC value of 84 (ECC: 84 ERR) which was obtained by XORing together the available symbols:

"120 027 033 057 065 000 108 000 027 034 041 026 118 126 126 126 126 126 040"

There are a few things wrong :

1) the message does not have ALL the symbols to work with (some have failed the earlier parity test and are displayed as ~~~ but are ignored in the overall checksum calculation)

2) the MMSI symbol "026" is wrong (in 99.9% of cases the final digit should be "0", but there are some rare exceptions, and AKAIK never used by coast stations)

3) the "040" symbol at the end is the "End of Sequence" symbol and cannot have a value of 040. The only acceptable values are
117 = REQ
122 = ACK
127 = EOS



Rosario, in general ONLY messages that have "ECC xx OK" are to be believed. If a message has "ECC xx ERR" this means the checksum has not calculated correctly and there are errors in the message - which could include the MMSI of the coast station.

Regards,

John

John Pumford-Green
 

On 24/07/2019 17:19, John Pumford-Green wrote:
Compare this to Rosario's message:
120 120 027 033 057 065 000 108 000 027 034 041 *026* 118 126 ~~~ 126
~~~ 126 126 126 ~~~ ~~~ 040 ~~~
His message shows that YaDD calculated an ECC value of 84 (ECC: 84 ERR) which was obtained by XORing together the available symbols:
"120 027 033 057 065 000 108 000 027 034 041 026 118 126 126 126 126 126 040"
A slight error in my explanation....

In Rosario's message YaDD calculated the ECC of 84 from the symbols:

120 027 033 057 065 000 108 000 027 034 041 026 118 126 126 126 126 126

This gives a value of 84.

Although the "040" is the "EOS" symbol YaDD doesn't use it in its ECC calculation:

The EOS symbol is sent 3 times:

In the "correct" version the final 4 symbols are :

122 062 122 122
EOS ECC EOS EOS


YaDD appears to only use the EOS found in the first of these positions. In Rosario's message this was not received (~~~).

~~~ ~~~ 040 ~~~
EOS ECC EOS EOS


The second EOS copy was received as "040" but is ignored in the ECC calculation. the value of "40" is what gives rise to YaDD's display of "EOS: UNK/ERR" since 40 is not a valid decipherable EOS symbol.


The message also contains no ECC value, so the assumed "transmitted ECC" is thus "0". The calculated "received ECC" is "84" and thus the ECC check leads to the "ECC 84 ERR" error being displayed ( 84 != 0 ).

Cheers,

John
Gm4SLV

ros.palermo@...
 

Hallo,Jay & Peter & John

Thank you all for your interest.
Your intervention John was exhaustive and formative.
You have all been very helpful.

73,Rosario