Cool, feel free to post your notes on this talk-ca list, its always helpfull to see other peoples views, perhaps you can describe the python sticking point you had? Perhaps others on this list can help?
Cheers, Sam On 2/5/10, JOHN SMART <[email protected]> wrote: > Hello Sam > > Yes I took an initial look at this stuff back in > November or so but got stuck at a python problem. Taking another look at it > now. I decided to try to write a few notes in my diary to record my > learning experience, mostly for my own benefit at this time. I had not > realised at first that it is a public diary but I did see that later. > > At this point I am learning, with a view to contributing some to the > map. Eventually I will probably put some Canvec data in and improve > some of the NB mapping (roads) that are there. If I have any questions > I'll be sure to ask. Probably if I do stick some data in I will ask for > people to review it to be sure I am doing the "right" thing. > > I have also browsed talk-ca a bit and there is much more I could learn in > there I'm sure. I see your name in there a lot :) > > John > > > > ________________________________ > From: Sam Vekemans <[email protected]> > To: Talk-CA OpenStreetMap <[email protected]> > Sent: Fri, February 5, 2010 9:06:15 PM > Subject: [Talk-ca] jsmart09's diary (canvec/ geobase discussion) > > Hi, Just forwarding this message, > It looks like we have someone interested in helping solve the CanVec.Geobase > Hydrography delema :-) > > > jsmart09's diary2010-02-04 > > Today I have looked through the Canvec documentation, which is here: > http://geogratis.cgdi.gc.ca/geogratis/en/collection/28954.html > In particular, the Data Product Specifications > http://ftp2.cits.rncan.gc.ca/pub/canvec/doc/CanVec_product_specifications_en.pdf > and the Feature Catalogue: > http://ftp2.cits.rncan.gc.ca/pub/canvec/doc/CanVec_feature_catalogue_en.pdf > I want to understand these so that I can understand the rules files that Sam > Vekemans has set up. > Incidentally Geobase or Canvec? From what I can see Geobase is an > initiative, to bring in data from multiple authorities. There is a > variety of types of geo data. Canvec is basically the NTS topo map data > but it has been reformatted / remodelled. New editions of Canvec are > brought out, apparently every 6 months. We are onto edition 4 for NB at > least for Fredericton area. The actual spatial data rarely seems to > change and some parts are just as out of date in the newest edition > (well actually they're more out of date!). > NRN (National Road Network) has been incorporated into Canvec so > there seems to be no difference in the data whether you get roads from > Canvec or from NRN files. > How to figure out what SHP file some entities / objects are in? Two > letter code indicates general theme e.g. HD is hydrography, TR is > transportation, TO is toponymy. Within the theme, there is a 7-digit > code that indicates the entity type (what I'd think of as "object > class"). E.g. 1480009 is the generic code for a Waterbody. Geometry > (point, line, area) is split out into separate SHP files. So we have > e.g. > 021g15_4_0_HD_1480009_2.shp for: > NTS tile 021G15 > Edition 4 > Version 0 > HD for hydrography > 1480009 for waterbody objects > 2 for area geometry > Inside this SHP file there are all the waterbody objects for the area of > 021G15. > To encode the particular types of waterbody object there are further > 7 digit codes, stored as the value of the CODE attribute. E.g. a CODE > 1480272 is an "unknown / non-isolated" waterbody. A 1480092 is a > "liquid waste, isolated" waterbody (i.e. a sewage holding pond) > Hydrography: I thought it might be simple to get lakes and rivers > out of Canvec, but some of the data is a bit strange. In 021G15 I have > Mactaquac Lake and a big chunk of the St John River as the same area > object. In Edition 3 it all had the name "Mactaquac Lake". Edition 4 > has removed the name. Likewise for the Oromocto River, a bunch of lakes > adjacent to the river are all bundled into the same area object as the > river. > So how does Toporama - > http://atlas.nrcan.gc.ca/site/english/maps/topo/map?mapsize=1150%201350&lat=45.85204497&long=-66.48944242&mapxy=2170329.14209+130644.561916&scale=5000000&feature_na=Oromocto+River&location1=13&unique_key=0c803390849c20c3b25c26ef7b645fbd&searchstring=oromocto%20river&entity=RIV&layers=fapfeature+nodata_ntdb_50k%20north_arrow%20other_features%20roads%20hydrography%20boundary%20builtup%20vegetation%20populated_places%20railway%20power_network%20manmade_features%20designated_areas%20water_features%20water_saturated_soils%20relief%20contours%20toponymy%20contour&urlappend=%26unique_key%3D0c803390849c20c3b25c26ef7b645fbd%26map.layer[textzoom03]%3DFEATURE+POINTS+2169671.31541+142309.976588+END+TEXT+%22Oromocto%2BRiver%22+END%26map.layer[textzoom46]%3DFEATURE+POINTS+2169671.31541+142309.976588+END+TEXT+%22Oromocto%2BRiver%22+END%26map.layer[lineresultzoom0]%3DDATA+fap_rivers%26map.layer[lineresultzoom1]%3DDATA+fap_rivers%26map.layer[lineresultzoom2]%3DDATA+fap > _rivers%26map.layer[arrowzoom03]%3DFEATURE+POINTS+2169671.31541+142309.976588+END+END > manage to get nice-ish looking lake and river names? Answer: there > are TO (toponymy) theme point objects which have been digitized > someplace inside the waterbody. As I mentioned above the waterbody > could encompass multiple lakes and rivers. There is no relationship at > all between the toponymy objects and the waterbodies. > TO objects seem to have a generic theme number 1580009. Each object > also has a CODE but its value always seems to be 1580010, for all the > names I've looked at. There is an additonal attribute, CONCISECODE, and > this is the one which differentiates e.g. French Lake (the lake, > CONCISECODE=150) from French Lake (the hamlet, CONCISECODE=80). > Actually if you look at the Feature Catalogue you can see that 80 is an > "unincorporated area). > How does OSM deal with area names? It seems it's all free and easy > and varies depending on your mood. I looked at a lake or two in Maine > and the area objects had no names but there were point names, like > Canvec has. I also looked at a couple of lakes in Switzerland and saw > that they had names as attributes of the lake edges. The Osmarenderer > seems to pick up those attributes for display as names (if you zoom in > far enough...) (Which raises another topic: where are the rules for the > renderer? If I knew that, I could figure out what attributes are useful > to include and what names to give them.. I think). > Back to the Canvec data. If I want to use the hydrography, I just > don't like the approach of the unrelated point objects. I'd prefer to > make the name an attribute of the area object. That would mean I had to > split up those humungous waterbodies into separate lakes and rivers. > More work. Should I do it the simple way first then make another pass > later to improve? Seems like the better approach. > Maybe tomorrow I shall take another look at Sam Vekeman's rules > files with a view to running the shp-to-osm.jar app to generate some > .osm from one or two .shp files. Then I'll look at those in e.g. GM. > I'll get a feel for what attribution the .osm is going to have. I > should try to find whether there is any accepted standard for > attribution for Canada at least. > Question (to myself, rhetorical!): do we want to > Posted by jsmart09 at Fri, 05 Feb 2010 02:51:03 +0000 in English (English) > ________________________________ > > Comment from acrosscanadatrails at Sat, 06 Feb 2010 01:04:33 +0000 > Hi, I've emailed the [email protected] list, and copied your > message, please join the list, as im sure others would be interested to > hear from you. > Cheers, > Sam Vekemans > acrosscanadatrails at gmail.com > > > > Twitter: @Acrosscanada > Blog: http://Acrosscanadatrails.blogspot.com > Facebook: http://www.facebook.com/sam.vekemans > Skype: samvekemans > OpenStreetMap IRC: http://irc.openstreetmap.org > @Acrosscanadatrails > -- Twitter: @Acrosscanada Blog: http://Acrosscanadatrails.blogspot.com Facebook: http://www.facebook.com/sam.vekemans Skype: samvekemans OpenStreetMap IRC: http://irc.openstreetmap.org @Acrosscanadatrails _______________________________________________ Talk-ca mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk-ca
