[Talk-ca] canvec or NHN

[Daniel Begin]

Hi,

 

About canvec/geobase. It's just as good in canvec as it is in geobase
(actually, depending on the process that creates it, the data is moved from
one product to the other) 

 

But there are slight differences between them and it makes me wondering if
it makes sense to copy everything from geobase. My question is the following
- How are we going to work/update/render duplicate feature?  

 

Why duplicate features?  NHN/geobase product has for (4) packages and
geometries may be duplicated between packages

 

For example, a lake is described in Hydrographic and Hydro Network packages
by at least two overlapped features . 

Bank (Hydro Network) - A feature delimiting all or part of a Waterbody
feature (ie at least one line, usually many line segments delimiting a
Waterbody)

Waterbody (Hydrographic) - A polygon feature describing a body of water
delimited by one or more Bank or Delimiter features (ie one closed line
describing the Waterbody)

 

It's the same with a small river/stream. It's described by at least two
overlapped lines .

Network Linear Flow (Hydro Network) - A feature that traces the movement of
water in a one-dimension virtual water flow route (ie a line that traces the
water flow)

Single Line Watercourse (Hydrographic) - A linear feature describing the
path of a narrow flow of water on the earth's surface (ie a line describing
the path of a narrow flow of water)

 

Should we really copy everything (packages) from geobase and put those
duplicates ways in osm?  For waterbody we might use a relation that point to
bank segments but it won't work for Network linear flow/single line
watercourse.  Anyway it's the same for many hydrographic features.  What
have been decided?

 

The subject may have been asked/answered before but I'm a kind of newbie in
Talk-CA so let me know !-)

 

Regards, 

 

Daniel

 

 

  _____  

From: samvekemans at gmail.com [mailto:samvekemans at gmail.com] On Behalf Of Sam
Vekemans
Sent: March 13, 2009 19:59
To: jfd553 at hotmail.com; Talk-CA OpenStreetMap; Kevin Farrugia; Simon Wood;
Michel Gilbert; Steve Singer
Subject: canvec or NHN

 

Hi thanks for the Summery details, much appreciated :)

 

As im going through the data, and have now matched up all the features, i
just have a few left in which I put a "*" and a note beside indicating that
it's a feature that needs to be proposed to the OSM community, so it can be
rendered differently.  (i think there are 20 or so left)

 

Anyway, what i want to know if the Geobase NHN data which is shown in the
CanVec set is just as good... or would it be better if i use the SHP files
direct from GeoBase NHN?  

 

http://www.geobase.ca/doc/catalogue/GeoBase_NHN_Catalogue_1.0.1_EN.html#Cont
ent

As im going through the list, they are described as 'names' rather than
canvec #'s making it slightly harder to spot if features are missing in the
canvec set.

 

 Thanks,

Sam Vekemans

Across Canada Trails

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