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i have got these two coordinates x and y from an external database.

X = 30490, y = 31430

was trying to figure out how to plot these coordinates on to google map? As google map only accept lat and lon value...

Any help is most appreciated!! Thanks...

winwaed
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Dayzza
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2 Answers2

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This may help.

How do I convert coordinates to a Latitude & Longitude?

Community
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Vishwanath
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You will need to know the coordinate system that was used for those coordinates. There are hundreds if not thousands of 'official' coordinate systems!

once you have the coordinate system, you can transform the coordinates to those used by Google (Longitude, Latitude degrees WGS84 with a spherical Earth).

You may want to do the transformation offline, but if you are doing it online with JavaScript, then take a look at the Proj4JS library.

For offline use, the standard open source library is Proj.4 but that is probably a bit daunting if this is your first experience with geographic coordinate systems and map projections.

winwaed
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  • any idea how to find out the coordinates sytems that is used? any file i should check.. sorry being very new in this. – Dayzza Nov 12 '10 at 05:48
  • whoever created the database is the most obvious answer. it may also depend on your area, eg. The UK uses the "National Grid" which is referenced to a point of the Scilly Isles. many US States have their own systems. UTM is another common system, but they don't look like UTM coordinates (they also have a zone which I don't see) – winwaed Nov 12 '10 at 13:40
  • if you have raw data files then Shapefiles often come with a PRJ file which contains the projection information. – winwaed Nov 12 '10 at 13:40