How to implement Network Triangulation?

I am developing an application in android 2.2 to identify location of user by Network:

1) First:

location= (GsmCellLocation)tm.getCellLocation();

cellId= location.getCid();

lac= location.getLac();

2) Second

wonder "http://www.google.com/glm/mmap" to get latitude and longitude and range.

3) Third

I repeat this step three times to obtain information from three different cells

How can I implement the triangulation? It is开发者_JAVA百科 possible to perform a mapping between latitude/longitude and xy co-ordinates?

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I think I've solved it... many thanks.

1. I have converted coordinates into radians.

2. I have changed the latitude/longitude (in radians) to ECEF xyz.

3. I've done some math to calculate the intersection of three circles.

4. I've re-converted the coordinates of this intersection, from ECEF to latitude & longitude and subsequently to degrees.

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You do linear interpolation with the vertices of the triangle you got.