[Talk-ca] Geobase data vs. OSM data on import

Austin Henry ahenry-ostcatalk at canoe.staticcling.org
Mon Jun 8 00:04:10 BST 2009


- Richard Weait arranged a host of electrons thusly: -
> On Sun, 2009-06-07 at 00:09 -0700, Austin Henry wrote:
> > Hi all,
> > 
> > I'm working on importing (most of) the 082E tile, 
> 
> Kelowna, Osoyoos, Grand Forks

That's the one.  Penticton was my original goal, because my Dad would
like to get involved in the project, and he lives there.  Figured it
would be nice for him to start from a place where the (for me) tedious
road mapping is done, and he can concentrate on the other stuff.

> > and the part of the
> > import process where you match roads in RoadMatcher is taking ages, 
> 
> Odd.  I've never seen RoadMatcher take more than about a minute to
> conflate.  Did you get any errors when opening the shape files?  

Oh, the conflation step takes about 30 seconds.  It's the manual step
after that to match the 100s of Km of highway with the geobase data
that was taking a long time.  Sometimes figuring out what should even be
matched was difficult, because the distance between the geobase road and
OSM road was up to about 80m (in a few places).

> We can expect the NRN to be generally "Excellent" with scattered "meh."
> They use better equipment than most of us.  Road centerlines should be
> right-on for when the data was taken.  The road configuration my have
> changed since then.  There may have been a construction diversion.  Or a
> large tractor-trailer in the next lane may have caused a reflection that
> hurt the location accuracy.  

That's what I figured, 

> Use your best judgement, you might be our only local expert for 082E.
> Continue to give preference to data from OSM contributors unless you
> have a good reason.  Consider contacting the previous contributors to
> see if they can shed some light on the discrepancies you are seeing.  

I had another look at some of the data in potlatch this morning, and it
looks like the majority of the areas I was having troubles with were
traced roughly from the low res yahoo imagery.

And to the local expert... well... I used to live in Penticton, and
never had my driver's license while I was there.  But I'll pass it over
to my dad after I've run the imports, and he's ridden his bike and
driven all over the place around there.  I'll pass the expert torch :)

> Best regards,
> Richard

Thanks for your help,
	Austin.


-- 
Build a man fire, he'll be warm for a day. 
Set a man on fire, he'll be warm for the rest of his life.




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