[Talk-ca] GeoBase import discussion Re: Talk-ca Digest, Vol 10, Issue 18
Sam Vekemans
acrosscanadatrails at gmail.com
Wed Dec 17 07:40:19 GMT 2008
Hi, very sorry i forgot to add you on the direct list before i sent it out.
I'm pleased to see that all the discussions were done direct from those who
deal with the data (the guy that did the Tiger Import, and the guy from the
Yukon, and from UBC)
I think i just need to talk to someone from GeoBC, as they would be
interested in these discussion too.
I also need to find someone from Nova Scotia & Alberta, as they would have a
good perspective also.
Have a great day,
Sam Vekemans
Across Canada Trails
On Tue, Dec 16, 2008 at 11:21 PM, <talk-ca-request at openstreetmap.org> wrote:
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> Today's Topics:
>
> 1. Re: GeoBase and OpenStreetMap (Dave Hansen)
> 2. Re: GeoBase and OpenStreetMap (Dan Putler)
> 3. Re: GeoBase and OpenStreetMap (Matt Wilkie)
> 4. Re: GeoBase and OpenStreetMap (Dave Hansen)
> 5. GeoBase Node Import idea ver 1.0 (Sam Vekemans)
>
>
> ----------------------------------------------------------------------
>
> Message: 1
> Date: Mon, 15 Dec 2008 14:32:37 -0800
> From: Dave Hansen <dave at sr71.net>
> Subject: Re: [Talk-ca] GeoBase and OpenStreetMap
> To: "Mepham, Michael" <Michael.Mepham at NRCan-RNCan.gc.ca>
> Cc: talk-ca at openstreetmap.org
> Message-ID: <1229380358.17206.244.camel at nimitz>
> Content-Type: text/plain; charset=UTF-8
>
> On Thu, 2008-12-11 at 15:02 -0500, Mepham, Michael wrote:
> > My first question has to be ?Why are you doing this??. I have spent
> > some time looking through the OSM web site and I understand the
> > rational for building street maps where none exist or at least are not
> > generally available but that is not the case here. I know of at least
> > two other complete downloads of the GeoBase data for redistribution
> > but still do not fully understand the reasons for replication /
> > duplication.
>
> The basic reason is that we need to be able to edit it. We can't simply
> put data back into GeoBase, so we need a copy on which to work. Is
> there a way we even could get changes back to the "owners" of the data?
>
> I think the core of it is that OpenStreetmap isn't your normal user. We
> don't want to just take the data and put it on a map, or figure out
> where all the residents in an area live. One of our core goals is to be
> able to update and change the map.
>
> > Secondly ? How does this group expect maintenance to work? When the
> > data suppliers pass updates to the GeoBase portal team and those
> > updates are made available then GeoBase and OSM will be out of sync.
> > What are the expectations on how or when they will be brought back
> > into sync?
>
> For the US TIGER data, we are simply diverging. There is no plan that I
> know of, and relatively little need right now, to bring things back into
> sync.
>
> It is just a huge problem with no easy solutions. The easiest solution
> that I see is what we're doing now: leave the data, and let the users
> improve it, just like the rest of the world.
>
> These huge government databases have, in effect, been a jump start for
> OSM. But, I'm afraid they're a one-time thing.
>
> -- Dave
>
>
>
>
> ------------------------------
>
> Message: 2
> Date: Mon, 15 Dec 2008 14:55:06 -0800
> From: Dan Putler <dan.putler at sauder.ubc.ca>
> Subject: Re: [Talk-ca] GeoBase and OpenStreetMap
> To: Dave Hansen <dave at sr71.net>
> Cc: talk-ca at openstreetmap.org
> Message-ID: <1229381706.6683.157.camel at whitebox>
> Content-Type: text/plain; charset=UTF-8
>
> Hi Dave,
>
> There is one important difference between the Canada NRN and the US
> TIGER data. Specifically, the locational accuracy for the NRN is much
> better than is the case with TIGER. As a result, the need to undertake a
> big effort editing ways to fix their locational accuracy isn't going to
> be nearly as critical (put another way, what do you trust more,
> someone's Garmin eTrex or the provincial highway department's Trimble
> differential gps unit?). As a result, the potential loss of information
> from "forking" the data is relatively more important for the Canada NRN
> then the US TIGER data. In my opinion the current US situation is
> unfortunate. As a data user you have the choice of one publicly
> available road network that is very good with respect to locational
> accuracy (OSM), and another that has much poorer locational accuracy but
> has address range and local area identifier information (TIGER) which
> allows it to be used in geocoding and certain types of routing
> applications (although, its locational accuracy is a problem for this).
> If the TIGER TILD's had been maintained on the OSM ways life would be a
> lot easier for a lot of potential users of the OSM data.
>
> My two cents.
>
> Dan
>
> On Mon, 2008-12-15 at 14:32 -0800, Dave Hansen wrote:
> > On Thu, 2008-12-11 at 15:02 -0500, Mepham, Michael wrote:
> > > My first question has to be ?Why are you doing this??. I have spent
> > > some time looking through the OSM web site and I understand the
> > > rational for building street maps where none exist or at least are not
> > > generally available but that is not the case here. I know of at least
> > > two other complete downloads of the GeoBase data for redistribution
> > > but still do not fully understand the reasons for replication /
> > > duplication.
> >
> > The basic reason is that we need to be able to edit it. We can't simply
> > put data back into GeoBase, so we need a copy on which to work. Is
> > there a way we even could get changes back to the "owners" of the data?
> >
> > I think the core of it is that OpenStreetmap isn't your normal user. We
> > don't want to just take the data and put it on a map, or figure out
> > where all the residents in an area live. One of our core goals is to be
> > able to update and change the map.
> >
> > > Secondly ? How does this group expect maintenance to work? When the
> > > data suppliers pass updates to the GeoBase portal team and those
> > > updates are made available then GeoBase and OSM will be out of sync.
> > > What are the expectations on how or when they will be brought back
> > > into sync?
> >
> > For the US TIGER data, we are simply diverging. There is no plan that I
> > know of, and relatively little need right now, to bring things back into
> > sync.
> >
> > It is just a huge problem with no easy solutions. The easiest solution
> > that I see is what we're doing now: leave the data, and let the users
> > improve it, just like the rest of the world.
> >
> > These huge government databases have, in effect, been a jump start for
> > OSM. But, I'm afraid they're a one-time thing.
> >
> > -- Dave
> >
> >
> > _______________________________________________
> > Talk-ca mailing list
> > Talk-ca at openstreetmap.org
> > http://lists.openstreetmap.org/listinfo/talk-ca
> --
> Dan Putler
> Sauder School of Business
> University of British Columbia
>
>
>
>
> ------------------------------
>
> Message: 3
> Date: Tue, 16 Dec 2008 12:15:57 -0800
> From: Matt Wilkie <matt.wilkie at gov.yk.ca>
> Subject: Re: [Talk-ca] GeoBase and OpenStreetMap
> To: Dave Hansen <dave at sr71.net>
> Cc: "Mepham, Michael" <Michael.Mepham at NRCan-RNCan.gc.ca>,
> talk-ca at openstreetmap.org
> Message-ID: <49480C7D.3020302 at gov.yk.ca>
> Content-Type: text/plain; charset=UTF-8; format=flowed
>
> Dave Hansen wrote:
> > The basic reason is that we need to be able to edit it. We can't
> > simply put data back into GeoBase, so we need a copy on which to
> > work. Is there a way we even could get changes back to the "owners"
> > of the data?
>
> This is a key question and worth exploring in depth. An off the cuff
> answer is that sometimes the owners will accept changes and sometimes
> not. As Mike outlined earlier, Geobase is a collection of data from
> various entities and thus sending updates back upstream will work (or
> not) differently depending who the provider is.
>
> Most of the data providers I work with are interested in feedback on
> their stuff (though sometimes it takes a fair bit of detective work to
> learn how to get that feedback to the right persons!). For OSM, I would
> probably start with the approach of learning who the closest to source
> provider is for data X, and submit "bug reports" and "patches" to them.
>
> Dear Office of Roads & Trails,
> I was recently biking 'Beaten Path' and discovered there is a
> washout at 131.32?W, 62.24?N, which looks a few years old, with
> a well travelled detour via 'Off The'. This was a bit of surprise
> as I was using your Hikes & Bikes Mapset and the half hour detour
> is not marked.
> The attached shapefile contains the detour captured with my
> XYZ GPS unit, with attributes and metadata conforming to your
> standards as seen on the Office of Roads & Trails ftp site.
> Sincerely,
> Oscar Steward Mapper
>
> A few iterations of this kind may eventually lead to a formal update
> mechanism.
>
> This paints a pretty rosy picture; there are generous and kindly people
> I know with GPS units whose data I would not accept as their enthusiasm
> outstrips their skill. Some filtering and verification is needed, but
> I'm confident that can be addressed if there is a will to do so.
>
> cheers,
>
> matt wilkie
> --------------------------------------------
> Geographic Information,
> Information Management and Technology,
> Yukon Department of Environment
> 10 Burns Road * Whitehorse, Yukon * Y1A 4Y9
> 867-667-8133 Tel * 867-393-7003 Fax
> http://environmentyukon.gov.yk.ca/geomatics/
> --------------------------------------------
>
>
>
>
>
> ------------------------------
>
> Message: 4
> Date: Tue, 16 Dec 2008 18:47:27 -0800
> From: Dave Hansen <dave at sr71.net>
> Subject: Re: [Talk-ca] GeoBase and OpenStreetMap
> To: Dan Putler <dan.putler at sauder.ubc.ca>
> Cc: talk-ca at openstreetmap.org
> Message-ID: <1229482047.17206.397.camel at nimitz>
> Content-Type: text/plain
>
> On Mon, 2008-12-15 at 14:55 -0800, Dan Putler wrote:
> > There is one important difference between the Canada NRN and the US
> > TIGER data. Specifically, the locational accuracy for the NRN is much
> > better than is the case with TIGER. As a result, the need to undertake a
> > big effort editing ways to fix their locational accuracy isn't going to
> > be nearly as critical (put another way, what do you trust more,
> > someone's Garmin eTrex or the provincial highway department's Trimble
> > differential gps unit?).
>
> >From the OpenStreetmap perspective, I think of it this way: do you want
> to trust some government dude who drove down my street once and decided
> how it should look on a map? Or, do you want to trust *me* who is on
> the street every day to decide how it should look on a map?
>
> > As a result, the potential loss of information
> > from "forking" the data is relatively more important for the Canada NRN
> > then the US TIGER data.
>
> I'm not sure I understand your argument. Are you saying that coming up
> with a plan to merge the OSM changes back into the NRN data is more
> important that it would be for the TIGER?
>
> > In my opinion the current US situation is
> > unfortunate. As a data user you have the choice of one publicly
> > available road network that is very good with respect to locational
> > accuracy (OSM), and another that has much poorer locational accuracy but
> > has address range and local area identifier information (TIGER) which
> > allows it to be used in geocoding and certain types of routing
> > applications (although, its locational accuracy is a problem for this).
>
> I actually think that locational accuracy is one of the smaller problems
> here. Yes, some of the TIGER data are atrocious. But, on a day-to-day
> basis, I'd be willing to be that the consumer's GPS and things like
> urban canyons cause more problems than TIGER inaccuracy.
>
> Are you saying that every single piece of data in the "GeoBase" data set
> has been verified with "the provincial highway department's Trimble
> differential gps unit"? I'd certainly believe that a good bit of it is.
> *But* a good bit of the TIGER data came from the same place: some very
> precise state and local government surveys. I believe the stuff created
> from aerial (not even satellite) maps tends to be the worst for
> locational accuracy.
>
> > If the TIGER TILD's had been maintained on the OSM ways life would be a
> > lot easier for a lot of potential users of the OSM data.
>
> The TLIDs were preserved for each and every way. I've introduced
> changes into JOSM to even preserve them as data are modified. Why would
> you think otherwise?
>
> -- Dave
>
>
>
>
> ------------------------------
>
> Message: 5
> Date: Tue, 16 Dec 2008 23:21:26 -0800
> From: "Sam Vekemans" <acrosscanadatrails at gmail.com>
> Subject: [Talk-ca] GeoBase Node Import idea ver 1.0
> To: "Mepham, Michael" <Michael.Mepham at nrcan-rncan.gc.ca>, "Michel
> Gilbert" <michcasa at gmail.com>, "Richard Weait" <richard at weait.com
> >,
> "Richard Degelder" <rtdegelder at gmail.com>, "Jason Reid"
> <osm at bowvalleytechnologies.com>, "Steve Singer"
> <ssinger_pg at sympatico.ca>, "Dale Atkin" <datkin at ibycus.com>,
> "Dan
> Putler" <dan.putler at sauder.ubc.ca>
> Cc: talk-ca at openstreetmap.org
> Message-ID:
> <9dbbf3b20812162321n3df6ca16m22718df82ad899e6 at mail.gmail.com>
> Content-Type: text/plain; charset="windows-1252"
>
> Hi there,
> After some serious review, (writing a hudge essays about the answer to the
> question. What do you want to get from GeoBase? (Answer: a better free
> wiki
> map showing more of Canada) and Why Import GeoBase to openstreetmap?
> (Answer: because it will make the map better)
> I came up with new questions and an idea.
>
> Question 1:
> >From looking at the entire GeoBase/CanVec collection, which is held in
> Sherbrook. Is this data stored in a form where the Images/Shapes/Lines are
> all available a nodes. .. a point in space?
> So for the images, 4 nodes representing that image cover area.
> For shapes, all the nodes representing the polygon, which has a relation
> together so the interface shows it as a shape.
> For the lines, it contains a series of nodes.
> If yes, then this should be true.
> Each node would have all the attributes which GeoBase needs to make the
> datasets, and to provide the WMS feed, and provide different types of data
> that you make available for all the different usergroups that GeoBase has.
>
> Question 2:
> Out of the CanVec collection which also has NID's, for Images/Shapes/Iines,
> these are also made up of a series of relations, so it knows that point
> A,B,C & D are all part of the polygon that make up this area... this area
> is
> labled.
> Then, looking at each node individually, your software that you use to
> extract this data, needs to know the exact coordinates of the node, and how
> it relates to eachother. Is that right?
>
>
>
> Here's the Idea:
>
> We import to OpenStreetMap the full NRCan/GeoBase/CanVec database.. not as
> shapes/ways/and lines.. but just as nodes.. and do not connect these nodes.
>
> We essentially import a Canada Node dump into OpenStreetMap, which shows
> all
> of the attributes that the nodes have. .. making sure to include:
>
> -NID
>
> -the name in English/French
>
> -the object type that NRCan uses.
>
> -the date at which the data was collected.
>
> -accuracy of the node
>
> -maybe the GPS coordinates
>
> ... and everything else that is relevant and included on the node. (and
> everything else which is needed for GeoBase/CanVec/NRCan 's use)
>
> -and the date at which it was imported into OSM (is already on there)
>
> -and who imported it.. is already on there
>
>
> Then after the "Great Canadian ? Node Dump Party".. we relax. And know
> that
> updates to GeoBase/CanVec/NRCan will be made available sometime.. and shown
> as more nodes to be added.
>
>
> Then after that..
>
> For those areas which contain no OSM data.. we can go ahead and import all
> the data as shape file/ways/lines/points.. and make up a possible OSM
> relation that it could be, we can fix the import script so then it would
> show it better (closer to what it should be). ... but don't really need to
> be that picky. (covering up the lonely nodes) ... it's kind of random... as
> thats whats made for the Ibycus topo map.. it's a match-up which is
> estimated, as a best guess. ... at least it shows up as the right colour
> and
> line type.. so when your looking at it on the Garmin.. its looks good. ...
> even though the ocean is listed as a lake. .. it's still blue...
> type=water.. as everything in the NHN thats a shape file.. and everything
> that is just a line can be a listed as a river. .. go for basics.
>
> ...
>
>
> The OpenStreetMap project is this:
>
> 'The Free Wiki World map'...
>
> It doesn't have to show exactly what GeoBase/NRCan says is there. ... this
> is why the nodes are imported... the nodes show all the technical details
> that GeoBase/NRCan/CanVec needs.
>
> When an update is available... we only import the new node dataset... and
> have the latest date attached as another tag. .. (it would anyway, but its
> important to have in planted in there, along with the source name)
>
>
> So for those areas which contain more data than GeoBase/CanVec (NRCan)
> has... all that will be made available is the nodes. .. so at all the
> intersections, there will be a point put in there.. and so, it would be up
> to the OSM Mappers discretion if they want to move the existing road-node
> on
> top of this node.. or leave it the way it is. .. the mappers can use those
> nodes as a 'guide' .. but not the 'rule' ... after all- we make up our own
> rules, and debate about it :) ... probably agree to import everything BUT
> the roads in many cases. :)
>
>
> These nodes will not be recognized by any renderer.. accept the GeoBase
> renderer, but it pulls the data from the feed. .. the real purpose these
> serve is to tell users that the road is 'officially-official' at that mark.
> ... as 'official-official maps are drawn from these nodes'... (and to use
> as
> a reference for OSM Mappers)
>
> (.. i would recommend importing all the different datasets from the
> different sources, and also importing the nodes from the source. .. so when
> the road numbers become available, they just show up as nodes... and wont
> effect the ways at all... as its a reference tool, as a program can be
> created to sort out all that stuff)
>
> (this way, government agencies are free to extract the specific tags out of
> the planet.osm file and should only get the NRCan data.) .. and make their
> own maps. ... and use OSM created stuff if they like. (cloudmade does show
> a
> file showing all the highway=* tags that are currently available)
>
>
> For most map users, weather or not the lines are 10 meters accurate or .5
> meters accurate. ...
>
> oh ya... Accuracy needs to be added if it isn't already a property of the
> NRCan -Canada dump node set.... ... remembering the discussion about
> accuracy vs. precision. If the nodes are already in the System, ya.. it's
> up
> to the user how many nodes they want to use. ... just like how many GPS
> track points you want to refer to when drawing a straight road.
>
>
> And so... for those areas in which contain 1 OSM 'thing', that particular
> user should be able to decide if they would like to import all of it, or
> just certain features.
>
> ...
>
> Then for the roads.. it would be a giant 'Connect-the-dots game'. ..
>
> ... it's a Wiki decision, so it would make sense that the road data would
> be
> the most sensitave area.. so for those tiles that are half mapped. .. these
> mapper would need help in, and those areas that have only 1 road. .. it
> would be worth it, to go ahead and import, rather than connect-the-dots.
>
>
> If these dots can ALSO be made available as a Plugin layer... WMS layer,
> we
> can see were these nodes have been moved (for reference, if needed)
>
>
> Pylons:
>
> Think of it this way:
>
> We have 1 billion pylons scattered all over Canada :)
>
> every pylon was placed there from Government of Canada. these are place
> holders, meant to tell GeoBase what exists at that point and how it relates
> to all the pylons around it. GeoBase keeps track of all the pylons, and all
> the information that is written on the pylon is legible by anyone. .. but
> some of it is just code.. and only needed for surveyors. ... but its all
> their and useful.
>
> All the different users out there can choose to use OpenStreetMap, when
> there working.. and simply double check to make sure that people didn't
> move
> the pylons, ... but most of the time... we trust each other, that these
> pylons were placed at this spot on purpose. :)
>
> And ya... pylons can be placed on top of each other.. where we know the
> latest pylon is on top
>
> JOSM might just 'squawk' at it. .. but there should be a way to look at
> each. .. anyway, the pylons are only to look at, and use if people want to
> use them.
>
>
> I hope that this makes sense.
>
> We can explore it further please :)
>
> Have a wonderful day,
>
> Sam Vekemans
>
> Across Canada Trails
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