Bonjour James, Really interesting suggestion! Actually, it is a natural step in data consideration : - First, you need data; - Then, you need information about the data!
So, I will soon include metadata generation in the conversion process. A Metadata.txt file will be added to each .zip file. This file will contain the following information about .osm files content. - DateRange: Years range at which the data was captured/validated - CMAS: Circular Map Accuracy Standard Value in meters (Circular Accuracy at 90%) - TagValue: Corresponding Osm feature tag The content of the Metadata.txt file will look like this... DateRange CMAS TagValue ------------------------- 2006-2011 03 highway=unclassified 2005-2011 03 highway=track 2005-2011 03 highway=secondary ... 1974-1974 25 tourism=attraction 1974-1974 25 railway=station 1974-1974 25 railway=rail 1974-1974 25 power=line 1974-1974 25 natural=wood 1974-1974 25 natural=wetland 1974-1974 25 natural=water ... 1974-1974 -1 natural=beach 1974-1974 -1 natural=bay 1974-1974 -1 leisure=nature_reserve Note: -1 stands for unknown values I'm completing tests and I'll add it to the conversion process. Regards, Daniel -----Original Message----- From: James A. Treacy [mailto:[email protected]] Sent: April 17, 2012 15:26 To: Bégin, Daniel Cc: Paul Norman; [email protected] Subject: Re: [Talk-ca] Canadian imports: good or bad? Daniel, As always, your work is really appreciated. Would it be possible, for at least some of the data, to have the age of the data included in the releases? While age by itself is not necessarily indicitave of the quality of the data, it is a factor that could help users when deciding to use it or not. For example, if I saw a road that was surveyed and built within the last 5 years I'd tend to put some trust in its location. If the data was 25 years old, not so much. On Tue, Apr 17, 2012 at 05:34:30PM +0000, Bégin, Daniel wrote: > Bonjour Paul, and all osmers > > Let me summarize the situation regarding NRCan-Canvec data. > > Good news... > - about a thousand files (maps) are brand new around Ellesmere Island > - Road network is updated every year for most of the provinces > > Old stories... > - YK,NT,NU were checked for changes about 10 years ago using 20m resolution > imageries. Some areas were updated using this imagery. > - We are replacing some of our hydrographic network with provincial data (BC > was the first replaced). It is usually more than 10 years old , our is older > than 25. > > Much older stories... > Actually, the rest of the NRCan-Canvec content is older than 25 years > (average 30, older 64). It concerns southern Canada... > - Buildings, railroads and other structures (obviously) > - Vegetation (wooded areas) - could soon be replaced with a 5 year old > automated classification using 30m imagery > - Wetlands > - Built-up areas > > You should not be surprise that some features are not up-to-date... > > I know that I've already done this exercise before but it is important > that the community is aware of the limitation of the data. This is the > same for all NRCan digital product (Canvec, Toporama, ...) and worst > for paper maps :-( > > As mentioned in another email, the main objective of providing the Canvec.osm > product was to help the community to focus on updating available data instead > of recapturing everything from scratch. And from there, eventually use it to > update our products. > > Since then, as a lot of Canvec data was imported, and updated ... > - we now use OSM data for changes detection (it help us planning GPS > field campaign for road updating in some provinces) > - we are looking at using OSM data to help us updating the entire Canvec > Product! > > It looks like a win-win situation for me! > > Best regards, > Daniel > > > Note: If anybody think this information should be added to the Canvec > wiki page, you can use the above information > > -----Original Message----- > From: Paul Norman [mailto:[email protected]] > Sent: April 17, 2012 05:00 > To: [email protected] > Subject: Re: [Talk-ca] Canadian imports: good or bad? > > > From: Ian Bruseker [mailto:[email protected]] > > Sent: Sunday, April 15, 2012 9:31 PM > > To: [email protected] > > Subject: Re: [Talk-ca] Canadian imports: good or bad? > > > > On 2012-04-15, at 6:37 PM, Steve Singer <[email protected]> wrote: > > > > > I also feel that not of all data sources are equal. Even within > > > Canvec some layers are excellent (ie roads and lakes in most of > > > the > > > country) while others are often so out of date it isn't worth the > > > time to import (ie buildings in much of Southern Ontario) > > > > > That's the third mention in a row of bad building data in Canvec. > > I'll chime in on that to say I found a hospital in St. Albert, > > Alberta that was marked as having come from an import. The hospital > > hasn't been there for 20 years. The new building is several > > kilometers away. Not just bad, full on dangerous if someone actually > > believed the data in OSM and tried to find help when they were hurt. > > :-( > > I thought it was just BC but it sounds like it's everywhere. > > Would I be correct in summarizing the opinions so far as 1. The buildings > data from CanVec should not be imported unless it can be verified against > imagery, in which case you might as well trace the buildings from imagery. > > 2. There is not a consensus among the community that CanVec data can be > imported without verifying the data for internal consistency and where > possible against imagery. > > > _______________________________________________ > Talk-ca mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-ca > > _______________________________________________ > Talk-ca mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk-ca -- James (Jay) Treacy [email protected] _______________________________________________ Talk-ca mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-ca
