location-formats
Location Formats
This is a list of previous efforts at location / geographic ("Geo") data formats and protocols, as background research for developing a location format.
vCard & hCard
vCard (RFC2426) and hcard includes 'adr', a way to markup addresses. There is also a field called 'geo' for lat/long.
UPU S42 & OASIS xNAL
UPU S42 is a standard for representing postal addresses. UPU, the Universal Postal Union, is the consortium of all national posts. See UPU S42 Announcement. xNAL, the XML Name and Address Language, is an earlier attempt to standardize on the components of addresses developed by OASIS, a consortium of business-process weenies. The distinction between vCard/hCard and S42/xAL/xNAL comes down to whether the address line elements themselves are decomposed. For example, in xNAL you can specify components like street number, street prefix directional, street name, street type, street postfix directional, subaddress type (Suite), subaddress number.
It is not always possible to conclusively determine these components from an address line, even in the US where addresses are more canonical than others. "A 4TH ST W STE 10" is a legal address line in the US. The street number and name are required (in the US) so this could be canonically decomposed as streetnumber="A", streetname="4TH", streettype="ST", postdirectional="W", subtype="STE", subtypenumber="10".
UPU S42 and OASIS xNAL standards are likely overkill for tagging general web content. However, they are important standards that should be considered in web-services involving both geocoding and reverse-geocoding. Perhaps standards related to decomposed addresses is something that should be placed on another page.
In addition, there should be pointers to national address standards.
USPS publishes a complete list of canonical abbreviations for both streettypes and subtypes. Their publications are self-inconsistent, but it is easy to infer the correct mappings. See USPS Acronyms & Abbreviations
New Zealand apparently adopted a variant of xNAL NZ xNAL Guidelines Release 1.0.
ICBM
Comma seperated list of lat/long <meta name="ICBM" content="XXX.XXXXX, XXX.XXXXX">
[1]
This is incorrect. It is one pair, not a list.
GeoUrl
Flickr Geotags
- Flickr GeoTagging A Greasemonkey script for adding lat and long tags to flick pictures. He uses Google Maps to get the lat and long. Users have to enter search terms (address, etc) and then select a point on the google map. Photos are tagged with "geo:lat=xx.xxxx", "geo:lon=xx.xxxx" and "geotagged" and aggregated at [2]
- A Flickr Group related to the topic
- A visual walkthrough of the technique.
- As of today (2005-06-01), 14k photos have been geotagged on Flickr.
- mappr, mapping flickr also support these geotags.
- flickr also supports EXIF headers, which can be used for storing location.
Geotagging
A2B
A2B is a location based search engine. Lat and long only. Seems to pick stuff up from geo meta tags. Pages can either be manually entered or pinged. They support lat/long and ICBM meta tags.
RSS
Several people have tried putting geographic information into RSS.
- This site uses icbm coordinates and has plugins for several blogging packages.
- BlogMapper - appears to be adding a namespace to RSS.
- BlogMap - picks up RSS extension and meta tag values
- worldKit RSS docs - worldKit advocates and understands various flavors of geocoded RSS; particularly the "geo" namespace.
- USGS earthquake feed - most widely used geocoded RSS feed
- Polygons and lines in polygons - A simple format for expressing polygons and lines is defined for worldKit
Address2Coordinates
Both of these systems are freely available sources of address to lat/long mappings (US only). I think they're based on US Census data, so they might be up to date.
- TIGER
- FIPS
- geocoder
- You can get coordinates from UK post-codes from streetmap
- Worldwide city level location data (over 4 million entries) is available from the GNS. This is accessible as a REST service from the worldkit geocoder
Plazes
Plazes is a system that does geo-info based on the network access point that the user's computer is connected to. They use tagging to identify locations.
Mapping Sites
Semantic Web
- Geosemantics Interest Group
- GeoOnion - a SW vocuabulary for relating items by distance from each other.
- RDFMap
- GeoRDF similar effort to collect prior art, for an effort in interoperability between OGC standards and various lightweight geo formats.
GML
Geographic Markup Language - a "600 page standard"
Google Earth XML
20050629 at Where 2.0 conference:
"Google Earth has an XML schema for describing a place on the earth. Will be releasing today or tomorrow." - John Hanke of Google/Keyhole.
Reverse engineered here today...
Google Maps API
- Google Maps API documentation
- KML = keyhole markup language KML Reverse Engineered Schema (for Google Earth, not Maps)
Yahoo Maps API
OGC
WCS
Web Coverage Service
NMEA
Standard and Proprietary NMEA Sentances
Wikipedia
Geo:Coordinates in Wikipedia Project
What People are Publishing
- links to mapping services, canonical URLs to 3rd party services like:
- Google Maps
- Map Quest
- Yahoo Maps
- human / named / legislated formats
- named places, e.g. Westin St. Francis
- addresses, including zip codes
- global/mathematical/geometrical
- Lat & Lon
- MAKE has a GeoURL button
- Geo in RSS. Means a particular blog post is associated with a specific lat/long. Not specific about whether it means the location that the post was made from or the location was the post was about.
- Lat & Lon
Other Formats
(move these into lists near top of document)
- GPX = GPS XML format
- Wikipedia markup styles