geo-extension-waypoints

Geo Waypoint Trails

An exploration of publishing information about sequences of geographical points using series of Geo (or other) microformats.

Terms

Conceptually, a collection of points, with no sequential relationship (the county towns of England, say, or all skyscrapers in New York), is deemed a collection (or set) of individual Waypoints. A sequentially-ordered collection of points may be expressed as a track or a route. Tracks are a record of where a person has been, routes are suggestions about where they might go in the future. So, for instance, there might be timestamps for each point in a track (because someone is recording where and when they were there), but timestamps for each point in a route are unlikely to be provided, because the author is suggesting it, and nobody might ever have travelled it.

A route which ends at its beginning may also describe a boundary (also called a box or polygon). A boundary may be for an object or area on any scale, from a small building or plot of land to a continent, at any level of granularity.

It may therefore be appropriate to use a sequence of hCalendar microformats for tracks and of hCard microformats for routes, boundaries and waypoints.

The Problem

To allow the publishing of series of waypoints in such a way that they are downloadable and that their ordering is parsable.

Participants

• Andy Mabbett

Real-World Examples

• Jiri to Everest Trek in Nepal
  • (or any other treks on that site)
  • relevant mark-up: <tr><td>Jiri Bus Park</td><td>27° 38.173'</td><td>86° 13.909'</td><td>1924</td></tr> ("1924" is the elevation)
• http://members.aol.com/gpspage/waypoints.html
• Freshman Seminar Waypoint Hunt
  • relevant mark-up: <tr><td>BENCH</td><td>40.33855</td><td>-74.66465</td><td><a href="bench.html"><img src="bench_c.gif" alt="[...]"></a></td></tr>

Collections

• POI66
  • example: Amsterdam CS-Alkmaar CS walking route (n.b long page; 612 waypoints)
  • relevant mark-up: <li><div>waypoint 10<br/>Latitude 52.386165<br/>Longitude 4.91199</div></li>

  <tr>
  <td>10</td>
  <td>
    <div class="geo">
      <span class="latitude">52.38616</span><br/>
      <span class="longitude">4.91199</span>
    </div>
  </td>
  <td ><a href="...">Waypoint 10</a></td>
  <td >Amsterdam (3 km) <a title="" href="...">Map</a></td>
  </tr>

Other

• GPX - XML schema for trails
  • GPX on Wikipedia
  • example (extract):

  <wpt lat="39.921055008" lon="3.054223107"> 
  <ele>12.863281</ele> 
  <time>2005-05-16T11:49:06Z</time> 
  <name>Cala Sant Vicenç - Mallorca</name> 
  <sym>City</sym> 
  </wpt>

Typical mandatory attributes

• Latitude (WSG84, using decimal or degrees-minutes-seconds values)
• Longitude (ditto)
• text label

Typical optional attributes

• timestamp
• elevation
• image
• note ?
• url ?

Issues

• How to indicate that a set of waypoints is a specific, but unordered, collection (i.e. a set of all the metro stations in Paris, and another set of all the underground stations in London, may be published on the same page)
  • KML uses "Folder" for each such set. e.g [1]
• How to sequence routes
  • Perhaps using order in source code, ordered lists, hCalendar or hAtom?
  • We could use hAtom and the feed category to distinguish between ordered, unordered and polygons.
    • hAtom requires both an author and date, neither of which are required for routes or polygons. Andy Mabbett
• How to timestamp tracks (timestamps imply a chronological sequence)
  • Perhaps using hCalendar?
• How to differentiate between a route (for example in the shape of a letter "U") and a boundary (or polygon) - in other words, to say whether or not, after the last point, the line returns to the first.
  • Suppose we use class="folder" for a sequence (per KML; see above). We could have class="folder route" or class="folder polygon".
• What can we learn, or use, from the GPX (XML schema for GPS data) specification?

References

• DCMI Box Encoding Scheme

Existing formats

A number of formats (which route/ track parsers may wish to export) are listed at http://www.gpsbabel.org/capabilities.html

GPS Babel is a free command line utility (there is a gui but it has limited functionality) for converting between these formats.

See Also

• Geo
• Geo cheatsheet
• Geo examples
• geo formats - previous/other attempts at geo related formats
• Geo brainstorming - brainstorms and other explorations relating to Geo (and Geo in hCard).
  • see also hCard brainstorming
• Geo advocacy - encourage others to use Geo.
• Geo examples in the wild
• Geo forms part of hcard, so please use:
  • hCard FAQ. If you have any questions about Geo, check the hCard FAQ.
  • hCard feedback
  • hCard issues
• location-formats - research which led to the development of Geo.
• proposed extensions
  • geo-extension-nonWGS84 - extend Geo for representing coordinates on other planets, moons etc.; and for other terrestrial schema
  • geo-extension-waypoints - extend Geo for representing: sets of waypoints; tracks; routes; and boundaries
• Geo profile - draft