Understanding map geometry

Windows Phone 7.5 supports two methods of map display in your mobile app:

• Bing Maps Silverlight Control for Windows Phone

• Bing Maps task Launcher

Before we delve into the methods, actions, and tasks of the Windows Phone Bing Maps Silverlight Control or the Bing Maps task Launcher, it is a good idea to get acquainted with the background of map geometry and how it works for Bing Maps. If you have a background in Computer Science, then you would be aware of keywords such as projection, trajectory, coordinate systems, raster and scalable graphics. If you are not from a Computer Science background, then a basic understanding of the Bing Maps API can be found at http://msdn.microsoft.com/en-us/library/ff428643.aspx. This should be good to get you started with Bing Maps.

Bing Maps uses the Mercator projection model of converting the Earth's sphere into a corresponding flat surface, grid-based, parallel map. In such a projection the longitude lines are parallel, and hence...