Coordinate System – Differences Between EPSG:4326 and EPSG:900913

coordinate systemepsg

I am a bit confused on EPSG:4326 and EPSG:900913. I thought that they were both same. Though as I am placing my features over GMaps, which is EPSG:4326, I need to define the srsname of the WFS layer as EPSG:900913 to get it into the right place. If I define srsname as 4326 it is projected somewhere completely wrong.

Could someone explain it a bit more in detail as to what is wrong here?

Best Answer

They are not the same. EPSG:4326 refers to WGS 84 whereas EPSG:900913 refers to WGS84 Web Mercator. EPSG:4326 treats the earth as an ellipsoid while EPSG:900913 treats it as a sphere. This affects calculations done based on treating the map as a flat plane which is why your features got plotted on the wrong places.

Related Solutions

Coordinate System – Difference Between WGS84 and EPSG:4326

4326 is just the EPSG identifier of WGS84.

WGS84 comprises a standard coordinate frame for the Earth, a datum/reference ellipsoid for raw altitude data.

[GIS] How to convert EPSG:26986 coordinate pairs to EPSG:4326 from the MassGIS web service, the Linux command-line, or PHP

Do you know about cs2cs ?

> # usage: cs2cs [proj.source] +to [proj.target]
> cs2cs -r +init=epsg:4326 +to +init=epsg:3857 << EOF
> 45 12
> 45 13
> EOF
1335833.89  5621521.49 0.00
1447153.38  5621521.49 0.00

I translated two coordinates (45ºN,12ºE) and (45ºN,13ºE) to EPSG:3857 (web mercator).

I specified -r (reverse) so to input latitude first (as is defined in EPSG:4326).

The third number in the output triplets is the height Z.

See man cs2cs (APT package is proj-bin here in APT world).

Best Answer

Related Solutions

Coordinate System – Difference Between WGS84 and EPSG:4326

[GIS] How to convert EPSG:26986 coordinate pairs to EPSG:4326 from the MassGIS web service, the Linux command-line, or PHP

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