Country detection failed: OH Finland CEPT prefix

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OE5JFE
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Country detection failed: OH Finland CEPT prefix

Post by OE5JFE » 29 Jun 2019, 13:50

Hello,

Today I hade a SOTA contact to Finland. The operating callsign was OH/OE6PGM/P
Entering that callsign to Log4OM still gave Austria as the country.
I manully needed to change to Finland.

It seams to happen only for OH/ CEPT prefix. Normal OH callsign work fine.

I tested the same callsign with other CEPT prefixes and that works fine too (ie. HB0/ also OH0/ (Aland island in Finland works) )

Version 1.38

73 de Joe

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G4POP
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Re: Country detection failed: OH Finland CEPT prefix

Post by G4POP » 29 Jun 2019, 15:28

I think this is because he should sign OH with a number 1 - 9/ because there as variations of OH so just the two letters is insufficient.

For example he could be in Aland Island OH0 where as OH1 through 9 are Finland

However I will double check this for you
73 Terry G4POP

OE5JFE
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Re: Country detection failed: OH Finland CEPT prefix

Post by OE5JFE » 29 Jun 2019, 21:21

Hi,

I have not found any addition of a number to OH in the CEPT rules for Finland. Only Aland Ilands have the 0 added.
Thanks for having a look.

73 de Joe

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IW3HMH
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Re: Country detection failed: OH Finland CEPT prefix

Post by IW3HMH » 01 Jul 2019, 09:41

Hi, this is a limit of the actual country detection system that does a "single pass" on the country file and get the first country that matches requisites.
This means each rule must be not overlapping with another rule, or the first rule parsed wins.

Aland island rules says:
^O[FGI]0.*|^OH0[A-LN-Z].*|^OH0.*

This will be used both for prefix and callsign, so a "strong" match with O<something>0(zero) is required or the system will go forward to find another suitable match, that by the way is Finland, with rule:

^O[F-J][1-9].*

This will match O<everything from F to J><number from 1 to 9>
Theoretically i can remove constraint [1-9] to let the system match finland as Aland is parsed before due to his position in the list, but this will rely on a not-safe condition that may create unpredictable issues (an user may manually change country file).

On the other side, this system is really fast.

On Version 2, to bypass this kind of issue we will parse callsign/prefix by length, exploring prefixes from the longest to the shortest. In this case, Finland matches all OH, while Aland matches OH0. If call or prefix is OH0 Aland is found before than Finland, if not, finland matches all.

This system elaborate public data from Clublog and make a valid system that is able to deal with prefix attribution along the decades, being able to correctly identify historical QSO countries even when the prefix has been reallocated in the latest years.

Unfortunately this system is much slower, and we experience an ADIF import 4 times slower than actual V1. Luckily it's a "one time" usage that can be widely accepted, as no noticeable impacts are present while running on normal QSO. We have actually no solutions for that issue, that is a peculiar situation. Moving V2 logic into V1 will require some days and a full retest of the engine. We'll think about but it's something we took from new major version release work
Daniele Pistollato - IW3HMH

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