Day1-1410-Challenges in geonames and address extraction

Friday 2:10pm, Room 1
Stefan Keller

http://2017.stateofthemap.org/2017/challenges-in-geonames-and-address-extraction/

Transcript

1. Challenges in geonames
   and address extraction
   Prof. Stefan Keller

   Geometa Lab HSR

   University of Applied Sciences 

   Rapperswil (Switzerland)
   

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2. Agenda
   • Motivation
   
   • Geonames
   
   • Adresses
   
   • Issues
   

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3. Geoname search:
   Where is Aizu-Wakamatsu?

   Address geocoding:
   Tokyo Central Post Office
   5-3, Yaesu 1-Chome
   Chuo-ku, Tokyo 100-8994
   

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4. Search components
   • Data

   

   

   • Data pre-processing software

   

   • Search engine software
   

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5. Geonames with
   containment hierarchy
   

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6. Geoname Ex.: Aizu
   

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7. Nominatim.osm.org
   

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8. OSMNames.org
   

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9. Enriched Geonames Data
   "name": "会津若松市",
   "alternative_names": „Aizuwakamatsu, Айдзувакамацу"
   "street": "",
   "county": "Fukushima",
   "city": "",
   "state": "Fukushima",
   "country": "Japan",
   "boundingbox": [139.8389,37.3229,140.1133,37.5831],
   "osm_id": "4174424",
   "type": "administrative",
   "importance": 0.4,
   …
   

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10. The power of hierarchy!
    1. country, national level (ev. main land!)
    
    2. state, subnational level
    
    3. city
    
    4. county/town
    
    5. village / suburb / neighborhood
    All administrative divisions are polygons (well: almost…)
    

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11. What’s a name anyway?
    • Toponymie: Endonym, Exonym.Example
    
    • name = ձ௡एদ৓
    
    • name:jp = ձ௡एদ৓ (Aizu-Wakamatsu-jō)
    
    • name:en = Aizu-Wakamatsu Castle
    
    • name:de = Burg Aizu-Wakamatsu
    
    • alt_name:en = Tsuruga Castle
    
    • alt_name:jp = ௽ϲ৓ (Tsuru-ga-jō)
    

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12. Issues in tagging geonames
    • Tag name: „Name is the name only“: Names are often misused to
    describe all kinds of things
    
    • Ranking of geonames!
    
    • Tag admin_level: There is no unified tagging yet in OSM for town
    parts and village parts
    
    • Issues in assigning hierarchy of city/town/village/suburb/
    neighborhood
    
    • How to deal with objects of larger aerial extent? Currently often
    captured as node: which to choose? what is the extent? what is
    the bbox?
    

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13. Addresses
    

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14. (Postal Building) Addresses
    • Given list of street geonames as processed before,
    including hierarchy
    
    • Select all OSM objects (node, way, relation) with key
    „addr:housenumber“ (Karlsruhe Schema)
    
    • Goal: Generate list of addresses pointing to a street
    (osm_id)
    

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15. Karlsruhe Schema
    Addresses can be tagged with key addr:housenumber and
    other addr keys on…
    
    • an node, isolated or other (e.g. shops)
    
    • a node on top of a building boundary with tag entrance=yes
    
    • a node on a polygon with key building
    
    • a node on a polygon representing the perimeter of a site
    
    • an relation with key associatedStreet
    
    • an invisible line (way) with key addr:interpolation
    

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16. Options to relate a house
    number to a street
    1. House number as part of relation exists? 

    
    
    2. Do addr:street or addr:place exists and match directly? 

    
    
    3. Apply fuzzy string/text search if street/place do not
    match.

    
    
    4. Apply street proximity search if there is no street/place

    
    

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17. Not covered here
    • Ways with addr:interpolation tag
    
    • Nodes with associated_street tag
    
    • POIs without addr:* get addr:* from buildings with addr:s
    
    • Zip codes
    
    • …
    

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18. Issues in tagging addresses
    • Misused name tags which introduce ambiguity
    
    • Sharing/deduplicating addr tags among objects inside a
    building polygon
    
    • addr nodes with entrance=yes sitting on top of a building
    (way): have to give addr to building (and building would
    have to give addy to everything inside
    
    • Special treatment of nodes with tag
    addr:housenumber=1;3;5 with values separated by
    semicolon
    

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19. Message to go
    • Addresses are an important asset of OSM
    
    • Geonames too
    
    • Wishlist:
    
    • A more consistent assignment of admin levels is needed
    
    • More consistent name content
    
    • Discussion on how to map geonames of larger aerial extent
    
    • …
    

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