无法在Google地图上映射坐标

Question

I have a list of coordinates that I want to plot on Google Maps, but I can't figure out how to do that. The coordinates, depending on how I plot them, appear to be all around the globe, while they should be placed in Trondheim, Norway. (And the application I have extracted them from successfully places them in Trondheim, so I know they are correct.)

A normal Google Maps coordinate from Trondheim looks like this:

63.4304, 10.395069

My coordinates, however, look like this:

long,    lat
1154262, 9182277
1143762, 9184473
1157168, 9194133
1157375, 9200167
1164505, 9209786

I believe that these are in some kind of WGS84 format, but as I am a complete novice on this field, I am not completely sure. I think so because of the headers in the XML I have extracted them from:

<rss version="2.0" 
xmlns:geo="http://www.w3.org/2003/01/geo/wgs84_pos#" 
xmlns:georss="http://www.georss.org/georss" 
xmlns:gml="http://www.opengis.net/gml" 
xmlns:mappoint="http://virtualearth.msn.com/apis/annotate#">

When I try to use this coordinate converter , it returns coordinates in Kazakhstan. I am utterly confused. All other converters I have tried either returns locations in strange countries or in the middle of the oceans, or they fail to convert my data at all.

Does anybody here know what kind of coordinates I have, and how I can convert them to normal latitude and longitude degrees?

A formula is enough, but if there exists any libraries for this, I am using C# as development language. Any other languages would suffice, however, as I am probably able to convert them to my own anyway.

Answer 1

WGS-84 is Spherical Mercator, the projection system used by Google, so the coordinates you have provided are obviously not. Unfortunately for any formula to work you will need to find out the projection that your points are in.

Some more detailed information on projection is available here: http://courses.washington.edu/gis250/lessons/projection/

And a library to convert between common coordinate systems in .net is available at: http://www.doogal.co.uk/dotnetcoords.php .

Would it be possible for you to open the map layer in an GIS program such as: http://www.qgis.org/en/site/ and use the options available to determine the projection of the layer?

Some tips for identifying the coordinate system (written for ARCGIS but the programs are similar): http://resources.arcgis.com/en/help/main/10.1/index.html#//003r00000004000000 https://gis.stackexchange.com/questions/7839/best-practices-for-identifying-the-unknown-coordinate-system-of-a-shapefile