Map

Database: geo_maps

This database is designed to store geo-based information like the street, node, regions.

• osm_node
• osm_way
• osm_highway
• hk_node
• hk_link

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osm_node

Nodes are used to define a standalone geo-points in the map. Some of the nodes have special meaning like the crossroad or postbox, while some other points only defined for the purpose to describe a street. Ref: http://wiki.openstreetmap.org/wiki/Node

• _id: an object id created by mongodb
• id: string, an unique id for all ndoes assigned by the osm system
• location: two elements array([lat, lon], lat, lon: float), the location of the node
• tag: description of node(k-v pairs, k and v are unicode string), the tag main contains

an example

 {
     "_id" : ObjectId("59145f9ae177d259648c7fc6"),
     u 'id': u '24330691',
     u 'location': [22.350627, 114.1849161]
     u 'name:en': u 'Hong Kong',
     u 'ref:en': u 'HK',
     u 'is_in:country': u 'China'
 }

---

osm_way

A way is an ordered list of nodes, it could be a region or a street. Ref: http://wiki.openstreetmap.org/wiki/Way

• _id: an object id created by mongodb
• id: string, an unique id for all way assigned by the osm system
• ng: [ref], ref is the id of nodes(osm_node.id)
• tag: description of node(k-v pairs, k and v are unicode string), the tag main contains

an example

 {
     u '_id': ObjectId('5929848c038f304e04bf2466'),
     u 'id': u '4181592',
     u 'nd': [u '253333910', u '3304026514', u '2291194554'],
     u 'tag': {
         u 'bridge': u 'yes',
         u 'layer': u '1',
         u 'name:en': u 'MTR Airport Express',
         u 'name': u '\u6e2f\u9435\u6a5f\u5834\u5feb\u7dab MTR Airport Express',
         u 'start_date': u '1998-07-06'
     }
 }

osm_highway

A highway is an ordered list of nodes, used for identifying any kind of road, street or path. Ref: http://wiki.openstreetmap.org/wiki/Key:highway

• _id: an object id created by mongodb
• id: string, an unique id for all way assigned by the osm system
• ng: [ref], ref is the id of nodes(osm_node.id)
• tag: description of node(k-v pairs, k and v are unicode string), the tag main contains

an example See the example of way

hk_node

All the nodes used for the "TRAFFIC SPEED MAP", the description can be found in Ref1 and the raw data can be found in Ref2 Ref1: https://data.gov.hk/en-data/dataset/hk-td-tis-traffic-speed-map Ref2: http://www.gov.hk/en/theme/psi/datasets/tsm_link_and_node_info_v2.xls Ref2: https://data.gov.hk/en/datagovhk-api/coordinate-conversion

• _id: an object id created by mongodb
• id: string, an unique id for all nodes in the tsm system
• hk80: hk1980 coordinates[northings, eastings], the methods transform hk80 to gps can be found in Ref3
• position: the corresponding gps results

an example See the example of way

 {
       "_id" : ObjectId("592a4619038f3082303a4620"),
       "position" : [22.28599503, 114.155241726],
       "id" : "722",
       "hk80" : ["816345.067", "834038.674"]
 }

hk_link

All the links used for the "TRAFFIC SPEED MAP", the description can be found in Ref1 and the raw data can be found in Ref2 Ref1: https://data.gov.hk/en-data/dataset/hk-td-tis-traffic-speed-map Ref2: http://www.gov.hk/en/theme/psi/datasets/tsm_link_and_node_info_v2.xls Ref2: https://data.gov.hk/en/datagovhk-api/coordinate-conversion

• _id: an object id created by mongodb
• id: string, an unique id for all links in the tsm system
• source: string, the id of source node
• source_position: [lat, lon], the gps position of source node
• target: string, the id of target node
• target_position: [lat, lon], the gps position of target node
• region: string, the region of the link: (HK – Hong Kong, K – Kowloon, TM – Tuen Mun, ST – Sha Tin)
• type: string, the type of road(MAJOR ROUTE – Refers to roads with speed limit of 70km/h or above; URBAN ROAD – Refers to roads with speed limit of 50 km/h )

an example See the example of way

 {
       "_id" : ObjectId("592a4619038f3082303a4620"),
       "id" : "722-50059"
       "source" : "722",
       "source_position" : [ 22.28599503, 114.155241726],
       "target" : "50059",
       "target_position" : [22.286866123, 114.15353399],
       "region" : "HK",
       "type": "MAJOR ROUTE",
 }