EPSG: 900913

What’s that? What is EPSG: 900913? Do not worry, it is just a coordinate system, I would say, widely use. It is just WGS 84 Web Mercator. It is used by major internet map providers as:

  • Google maps
  • Bing maps
  • OpenStreet maps

It is coordinate system with high numbers. It is x/y axis coordinate system. It is EPSG:900913!

Beginning of EPSG: 900913

When Google and Bing started doing maps, it became more mainstream. From that time not only gis specialist started to work with maps, but also other people as well. For example web application developers. 26. June 2006 was new open source Javascript library initially released. Its main focus was displaying map data in web browsers. It is called OpenLayers. It is great web technology for displaying different type of map sources, for example WMS, WFS, KML, GML,… The ability to connect to almost every type of spatial data served by web, geo or tiling servers makes this library so powerful.

When  Mr. Christopher Schmidt was pinged by SharpGis, and was told that he should rework projection system for Google. After rework (sometimes before 6th August, 2007) OpenLayers developers had need for EPSG number. It was defined, but European Petroleum Survey Group did not allow to create this projection system, saying (as Mr. Morten Nielsen wrote here):

We have reviewed the coordinate reference system used by Microsoft, Google, etc. and believe that it is technically flawed. We will not devalue the EPSG dataset by including such inappropriate geodesy and cartography.

And this was the beginning of number 900913. After reject of EPSG, they decided their own number, which will not be in conflict with EPSG number ranges. EPSG: 900013 is GOOGLE in a 1447 leet alphabet. And it became popular:

9 – g
0 – o
0 – o
9 – g
1 – l
3 – e

Dead of EPSG: 900913

After this coordinate system became popular. EPSG changed their mind 🙂 Or just reevaluate their decision. And they created said yes to google projection. But they did not accept this great and special number EPSG: 900913! Instead of EPSG: 900913 they created new one: EPSG:3758. But after year they deprecated this number because of issues, and created new definition EPSG:3857 – WGS Pseudo-Mercator, which is used until these days!

PROJCS[“WGS 84 / Pseudo-Mercator”,
GEOGCS[“WGS 84”,
DATUM[“WGS_1984”,
SPHEROID[“WGS 84”, 6378137, 298.257223563, AUTHORITY[“EPSG”,”7030″]],
AUTHORITY[“EPSG”,”6326″]],
PRIMEM[“Greenwich”, 0, AUTHORITY[“EPSG”,”8901″]],
UNIT[“degree”, 0.01745329251994328, AUTHORITY[“EPSG”,”9122″]],
AUTHORITY[“EPSG”,”4326″]],
PROJECTION[“Mercator_1SP”],
PARAMETER[“central_meridian”,0],
PARAMETER[“scale_factor”,1],
PARAMETER[“false_easting”,0],
PARAMETER[“false_northing”,0],
UNIT[“metre”, 1, AUTHORITY[“EPSG”,”9001″]],
AXIS[“X”,EAST],
AXIS[“Y”,NORTH],
AUTHORITY[“EPSG”,”3857″]]

So just enjoy beautiful sound of history…

And do not be lost… You’ve got MAPS.

 

Please tell what you think