Re: [Tagging] Is the difference between power station and sub station clear?

[oligo]

I completely second these arguments: using power=substation whatever the 
size of the substation, and storing other details in other tags.


In the wiki we could encourage mappers to no longer use power=station 
(and power=sub_station if we decide to abandon it as well), that way 
we'll slowly migrate to the new tagging power=substation while 
maintaining backward compatibility.


Olivier

Le 27/01/2013 16:04, Janko Mihelic' a écrit :
2013/1/27 Martin Koppenhoefer >


2013/1/26 François Lacombe mailto:francois.laco...@telecom-bretagne.eu>>:

-1, don't share this idea. IMHO a completely different substation
apperance and size, usage etc. are sufficient arguments to keep
different main entities (classes) in osm. There is no rule that we
have to have strictly functional classification, and in the past
mappers had found it useful to have the classes like this.


History has shown that mappers around the world have been mapping 
substations differently, because these two tags are so vague. They 
have been mapping power plants with power=station, big substations 
with power=sub_station, little substations with power=station.Why? 
Because a mapper layman has to know the difference between a high 
voltage substation, and a middle/lower voltage substation to map them 
correctly. That is a recipe for faults.


If you only have power=sub_station, beginners are much more likely to 
map correctly. And if they know more, they can put in a 
voltage=high;medium;low. But even if they don't, you can guess which 
kind of a station it is. If it has power=sub_station + building=yes, 
it is probably a middle or low voltage substation. If the area of the 
power=sub_station is bigger than 60m2, then it is probably a high 
voltage substation. I think that is much better than to force the 
mapper layman to decide.


Janko Mihelic'


___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging


___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[François Lacombe]

2013/1/27 Martin Koppenhoefer 

> why using 2 tags if you can solve it with one ;-)
>

1 tag = 1 idea. Think versatile.

 2013/1/27 Janko Mihelić 

> You also have to map these two with same tags, but mappers have no
> problems with that:
>
> http://farm4.staticflickr.com/3231/3612088299_4886057d1b_z.jpg
>
> http://1.bp.blogspot.com/_q4w5GY0uBAU/TG2j3tGzz2I/BLg/EQ9YBbhrwz4/s1600/Large+view+of+school.JPG
>
> And these:
>
>
> http://3.bp.blogspot.com/-FboxEgz3Zm8/ToN98JRlyyI/BLs/uIfFLPEqR7E/s1600/St%2BPeters%2B1.jpg
>
> http://pixelprayers.com/wp-content/uploads/2012/03/1.1274402303.the-world-s-smallest-church.jpg
>
> The word "substation" says nothing about it's size, just like "school" or
> "church". Why should we invent new meanings for words?
>
>
+2e8000. Good job :)


*François Lacombe*

francois dot lacombe At telecom-bretagne dot eu
http://www.infos-reseaux.com
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Ole Nielsen]

On 27/01/2013 17:15, Janko Mihelić wrote:

You also have to map these two with same tags, but mappers have no
problems with that:

http://farm4.staticflickr.com/3231/3612088299_4886057d1b_z.jpg
http://1.bp.blogspot.com/_q4w5GY0uBAU/TG2j3tGzz2I/BLg/EQ9YBbhrwz4/s1600/Large+view+of+school.JPG

And these:

http://3.bp.blogspot.com/-FboxEgz3Zm8/ToN98JRlyyI/BLs/uIfFLPEqR7E/s1600/St%2BPeters%2B1.jpg
http://pixelprayers.com/wp-content/uploads/2012/03/1.1274402303.the-world-s-smallest-church.jpg

The word "substation" says nothing about it's size, just like "school"
or "church". Why should we invent new meanings for words?


+1

Ole / polderrunner


___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Janko Mihelić]

2013/1/27 Martin Koppenhoefer 

>
> If you have a closer look you will find that
> there are lots of different types for substations, e.g. transmission
> substations, distribution substations, collector substations,
> converter substations, switching substations, etc.
> Voltage is just one possible criterion for their classification, there
> are also different ones possible (as always).
>

That's the best possible reason for a unique substation tag. You have
power=sub_station + substation:type=switching;converter;collector +
substation:structure=pole;tower;house...

That way unrelated renderers only look at the power=sub_station tag, and
don't bother about all the different substation types that exist (or will
exist).

Janko
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Martin Koppenhoefer]

2013/1/27 Janko Mihelić :
> The word "substation" says nothing about it's size, just like "school" or
> "church". Why should we invent new meanings for words?


As the word "substation" doesn't distinguish between those two: maybe
it is not a good choice for the tag? IMHO it feels like a step back
instead of progression. If you have a closer look you will find that
there are lots of different types for substations, e.g. transmission
substations, distribution substations, collector substations,
converter substations, switching substations, etc.
Voltage is just one possible criterion for their classification, there
are also different ones possible (as always).

cheers,
Martin

___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Janko Mihelić]

2013/1/27 Martin Koppenhoefer 

>
> OK, but then they would have to map this:
> http://www.flickr.com/photos/mamboman/448479749/
> and this:
> http://www.flickr.com/photos/rene-germany/5723334544/
> http://www.flickr.com/photos/zarner01/6899597110/
>
> with the same tags. Why not have distinct classes for those two?
>

You also have to map these two with same tags, but mappers have no problems
with that:

http://farm4.staticflickr.com/3231/3612088299_4886057d1b_z.jpg
http://1.bp.blogspot.com/_q4w5GY0uBAU/TG2j3tGzz2I/BLg/EQ9YBbhrwz4/s1600/Large+view+of+school.JPG

And these:

http://3.bp.blogspot.com/-FboxEgz3Zm8/ToN98JRlyyI/BLs/uIfFLPEqR7E/s1600/St%2BPeters%2B1.jpg
http://pixelprayers.com/wp-content/uploads/2012/03/1.1274402303.the-world-s-smallest-church.jpg

The word "substation" says nothing about it's size, just like "school" or
"church". Why should we invent new meanings for words?

Janko
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Martin Koppenhoefer]

2013/1/27 François Lacombe :
> 2013/1/27 Martin Koppenhoefer 
>> the sense in OSM is perfectly clear and defined in the osm wiki:
>> power=station describes a substation for high voltage.
>> power=sub_station is a substation for transforming medium to low
>> voltage. This is also defined in the wiki.
>
> This discussion shows there's a little doubt about the correctness of this
> business.


yes, you can always find someone in OSM who disputes the way stuff is
mapped. I also agree with you in principle that the current situation
is unfortunate, because the tags are not corresponding with the actual
linguistic meaning of the words used, and this might cause confusion
and problems. Redefining the same tags also causes confusion and most
probably wrong tagging. Your ideas are not stupid (using different
words instead of redefining in-use ones, e.g. substation for
substations (instead of the in-use "sub_station") and plant instead of
station or generator (hope I got this right and this is what you
want). Still a different key would make it less error-prone (the
differences are somehow subtle and you want to reuse generator for
generators i.e. a different thing than what they are used now).


> If mappers see a substation, they can map a substation in OSM,
> power=substation.
> But if they can't determine the voltage, they're not required to put this
> information in their upload instead of publishing wrong data.


OK, but then they would have to map this:
http://www.flickr.com/photos/mamboman/448479749/
and this:
http://www.flickr.com/photos/rene-germany/5723334544/
http://www.flickr.com/photos/zarner01/6899597110/

with the same tags. Why not have distinct classes for those two?


> Putting two tags instead of one allows people to act like that.


why using 2 tags if you can solve it with one ;-)


> How can you be sure the distinction you made is right if voltage isn't
> mandatory in the equation?


2 main tag-values for quite different looking objects ensure (in my
opinion) much better the consistency of the data than relying on
voltage-values (which also might be missing quite a lot, following
your own suggestion to omit this in case of doubt).

cheers,
Martin

___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Janko Mihelić]

2013/1/27 Martin Koppenhoefer 

> 2013/1/26 François Lacombe :
>
> -1, don't share this idea. IMHO a completely different substation
> apperance and size, usage etc. are sufficient arguments to keep
> different main entities (classes) in osm. There is no rule that we
> have to have strictly functional classification, and in the past
> mappers had found it useful to have the classes like this.
>

History has shown that mappers around the world have been mapping
substations differently, because these two tags are so vague. They have
been mapping power plants with power=station, big substations with
power=sub_station, little substations with power=station.Why? Because a
mapper layman has to know the difference between a high voltage substation,
and a middle/lower voltage substation to map them correctly. That is a
recipe for faults.

If you only have power=sub_station, beginners are much more likely to map
correctly. And if they know more, they can put in a
voltage=high;medium;low. But even if they don't, you can guess which kind
of a station it is. If it has power=sub_station + building=yes, it is
probably a middle or low voltage substation. If the area of the
power=sub_station is bigger than 60m2, then it is probably a high voltage
substation. I think that is much better than to force the mapper layman to
decide.

Janko Mihelić
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[François Lacombe]

Hi Martin,

2013/1/27 Martin Koppenhoefer 

>
> the sense in OSM is perfectly clear and defined in the osm wiki:
> power=station describes a substation for high voltage.
> power=sub_station is a substation for transforming medium to low
> voltage. This is also defined in the wiki.
>
This discussion shows there's a little doubt about the correctness of this
business.


> why should we create a situation where you will no more be able to map
> substations if you don't know the voltage? There is really no
> advantage from excluding mappers.
>
That wasn't my idea.

If mappers see a substation, they can map a substation in OSM,
power=substation.
But if they can't determine the voltage, they're not required to put this
information in their upload instead of publishing wrong data.

Putting two tags instead of one allows people to act like that.


> fine. You can do this. But it isn't necessary to keep this in mind to
> map substations. Never had a problem distinguishing power=station from
> power=sub_station.
>
How can you be sure the distinction you made is right if voltage isn't
mandatory in the equation?

If all kind of substation are mapped with power=substation, the set could
just incomplete because we'll sometimes lack the voltage tag but existing
data is obviously right.
If the distinction is made on the power tag value, mistakes are easier to
be made.


I've got an answer from aliponte this morning. I'll ask him if I can
copy/paste his whole message here as for not extracting sentences from
their context.

Cheers.


-- 
*François Lacombe*

francois dot lacombe At telecom-bretagne dot eu
http://www.infos-reseaux.com
___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging

Re: [Tagging] Is the difference between power station and sub station clear?

[Martin Koppenhoefer]

2013/1/26 François Lacombe :
> According to some previous explanations, power=station and power=sub_station
> must be renamed since the sense isn't clear at all.


the sense in OSM is perfectly clear and defined in the osm wiki:
power=station describes a substation for high voltage.
power=sub_station is a substation for transforming medium to low
voltage. This is also defined in the wiki.


> If "normal" (what is normal please?) mappers don't know the voltage, they
> don't upload data, that's all.


why should we create a situation where you will no more be able to map
substations if you don't know the voltage? There is really no
advantage from excluding mappers.


> We can have the information just by looking how the substation is built. Air
> insulation distances are highly representative of the voltage. A wiki page
> already gives the method : 1m per 100kV.
> http://wiki.openstreetmap.org/wiki/Key:voltage


fine. You can do this. But it isn't necessary to keep this in mind to
map substations. Never had a problem distinguishing power=station from
power=sub_station.


> Physically : You're right, I see a difference. But it's only due to voltage.
> Voltage is requiring air insulation distances which must be respected! Thus,
> in a 400 kV substation, design will be very different than the residential
> surburbs 380V one. Moreover, power exchanges between the two interfaces of a
> power transformer has an influence on the size of that transformer. That's
> all.
> Functionally : It's the same. The power is switched and transformed the same
> way in both places. There's really no difference.


maybe you have to accept that OSM tagging is not always following
consistent classifications or logics. Please keep in mind that we are
not discussing how we could map something that wasn't mapped until
now. You are questioning the established system of how things were
done in the past years (and which had worked well until now). We (i.e.
the community) should decide if the benefits of introducing more
consistency are bigger than the hazzle which mappers, editor
maintainers and data consumers will have when changing the system.

To reduce potential problems I still suggest not to remain under the
"power"-key with a potential redesign but INTRODUCE A NEW KEY!


> With this in mind, we'd better to tag every substation with power=substation
> and put any extra tag to define what kind of substation it is.


-1, don't share this idea. IMHO a completely different substation
apperance and size, usage etc. are sufficient arguments to keep
different main entities (classes) in osm. There is no rule that we
have to have strictly functional classification, and in the past
mappers had found it useful to have the classes like this.

cheers,
Martin

___
Tagging mailing list
Tagging@openstreetmap.org
http://lists.openstreetmap.org/listinfo/tagging