GeoRSS

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GeoRSS is a standard to using web feeds a georeferencing to be transmitted.

GeoRSS can be used by extending RSS  1.0, RSS 2.0 or Atom .

History and background

GeoRSS-Simple is a lightweight format that only supports basic geometries (point, line, box, polygon) and covers typical applications for georeferenced data. GeoRSS-GML is based on the GML format of the Open Geospatial Consortium (OGC) and supports a broader range of geometry objects than GeoRSS-Simple, in particular coordinate systems other than WGS84 . There is also a coding introduced by the W3C that, although partially out of date, is very widespread.

GeoRSS also serves informally as an extension of the W3C Geo (point) vocabulary by adding important additional types of positions (points, lines and boundaries) as well as other possibilities for extension.

In March 2007 GeoRSS was added to the Google Maps API together with KLM . The aim is to ensure that users are able to create data in any format and upload it to Google Maps.

Based on RSS, there are the following standards:

  • GeoRSS-Simple
  • GeoRSS- GML

geometry

The geometric shapes that can be used to represent the position in GeoRSS are point, line and boundary.

A point contains a single pair of coordinates. The coordinate pair contains a latitude value and a longitude value in that order. The preferred serialization of this method uses a space to separate the two values.

line

A line contains two or more pairs of coordinates. Each pair contains a latitude value and a longitude value in that order. The preferred serialization of this method uses a space to separate the two values. Pairs are separated from each other by a space.

square

A square contains exactly two pairs of coordinates. Each pair contains a latitude value and a longitude value in that order. The preferred serialization of this method uses a space to separate the two values. Pairs are separated from each other by a space. The first pair of coordinates (bottom corner) must be a point further west and south of the second pair of coordinates (top corner), and the box is always interpreted to mean that it does not contain the 180 (or −180) degree longitude line that is not at its boundary, and does not contain the North or South Pole except on its boundary. A box is typically used to roughly delimit an area that contains other data.

Polygon

A polygon contains at least four coordinate pairs. Each pair contains a latitude value and a longitude value in that order. The preferred serialization of this method uses a space to separate the two values. Pairs are separated from each other by a space. The last pair of coordinates must be identical to the first.

Coding

The individual components are coded as follows.

GML : point <gml: point> point>

  • Line <gml: LineString> string
  • Polygon <gml: polygon> polygon>
  • Square <gml: envelope>

GeoRSS Simple:

  • Point <georss: point> point>
  • Line <georss: line>
  • Polygon <georss: polygon >>
  • Square <georss: box>

advantages

The advantages of GeoRSS feeds lie in the possibilities of geographic search and aggregation. With GeoRSS it is possible to search for all geographical criteria, for example all earthquake-relevant areas within 200 kilometers around a certain location.

Examples

GeoRSS-Simple using Atom: 

 <?xml version="1.0" encoding="utf-8"?>
 <feed xmlns="http://www.w3.org/2005/Atom"
       xmlns:georss="http://www.georss.org/georss">
   <title>Earthquakes</title>
   <subtitle>International earthquake observation labs</subtitle>
   <link href="http://example.org/"/>
   <updated>2005-12-13T18:30:02Z</updated>
   <author>
      <name>Dr. Thaddeus Remor</name>
      <email>tremor@quakelab.edu</email>
   </author>
   <id>urn:uuid:60a76c80-d399-11d9-b93C-0003939e0af6</id>
   <entry>
      <title>M 3.2, Mona Passage</title>
      <link href="http://example.org/2005/09/09/atom01"/>
      <id>urn:uuid:1225c695-cfb8-4ebb-aaaa-80da344efa6a</id>
      <updated>2005-08-17T07:02:32Z</updated>
      <summary>We just had a big one.</summary>
      <georss:point>45.256 -71.92</georss:point>
   </entry>
 </feed>

GeoRSS-GML using RSS 2.0: 

  <?xml version="1.0" encoding="UTF-8"?>
  <rss version="2.0"
       xmlns:georss="http://www.georss.org/georss"
       xmlns:gml="http://www.opengis.net/gml">
    <channel>
    <link>http://maps.google.com</link>
    <title>Cambridge Neighborhoods</title>
    <description>One guy's view of Cambridge, MA</description>
    <item>
      <guid isPermaLink="false">00000111c36421c1321d3</guid>
      <pubDate>Thu, 05 Apr 2007 20:16:31 +0000</pubDate>
      <title>Central Square</title>
      <description>The heart and soul of the "old" Cambridge. Depending on where you
               stand, you can feel like you're in the 1970s or 2020.</description>
      <author>rajrsingh</author>
      <gml:Polygon>
        <gml:exterior>
          <gml:LinearRing>
            <gml:posList>
              -71.106216 42.366661
              -71.105576 42.367104
              -71.104378 42.367134
              -71.103729 42.366249
              -71.098793 42.363331
              -71.101028 42.362541
              -71.106865 42.366123
              -71.106216 42.366661
            </gml:posList>
          </gml:LinearRing>
        </gml:exterior>
      </gml:Polygon>
    </item>
   </channel>
 </rss>

GeoRSS-Simple using RSS 2.0 according to W3C: 

 <?xml version="1.0"?>
 <?xml-stylesheet href="/eqcenter/catalogs/rssxsl.php?feed=eqs7day-M5.xml" type="text/xsl"
                  media="screen"?>
 <rss version="2.0"
      xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#"
      xmlns:dc="http://purl.org/dc/elements/1.1/">
  <channel>
     <title>USGS M5+ Earthquakes</title>
     <description>Real-time, worldwide earthquake list for the past 7 days</description>
     <link>http://earthquake.usgs.gov/eqcenter/</link>
     <dc:publisher>U.S. Geological Survey</dc:publisher>
     <pubDate>Thu, 27 Dec 2007 23:56:15 PST</pubDate>
     <item>
       <pubDate>Fri, 28 Dec 2007 05:24:17 GMT</pubDate>
       <title>M 5.3, northern Sumatra, Indonesia</title>
       <description>December 28, 2007 05:24:17 GMT</description>
       <link>http://earthquake.usgs.gov/eqcenter/recenteqsww/Quakes/us2007llai.php</link>
       <geo:lat>5.5319</geo:lat>
       <geo:long>95.8972</geo:long>
     </item>
   </channel>
 </rss>

Examples of GeoRSS implementations

Example feeds

Use and implementation

  • GeoPress WordPress and MovableType plugins for adding GeoRSS to a blog.
  • MapQuest MapQuest Embeddable Map using GeoRSS Feed

Open source projects

Products

  • Cadcorp (PDF; 162 kB) GeoRSS built into Cadcorp SIS.
  • CubeWerx WFS (PDF; 242 kB) The new release of the CubeWerx OGC Web Feature Service product supports GeoRSS GML.
  • Ionic / Leica Geosystems The use of GeoRSS in Ionic redSpider products
  • Bay of Islands Contains GeoRSS information about local accommodation
  • MarkLogic Provides support for geospatial queries using GeoRSS / Simple markup.

Web links

Individual evidence

  1. ↑ a b GeoRSS Overview. Retrieved June 2, 2019 .
  2. ↑ KML and GeoRSS Support Added to the Google Maps API. March 21, 2007, accessed June 2, 2019 .
  3. ↑ GeoRSS model. Retrieved June 2, 2019 .
  4. ↑ GeoRSS in Atom. Retrieved June 2, 2019 .