My Location: smaller is better!

My Location just got better for all the applications that use Google's geolocation service!

In November 2007 we launched My Location on Google Maps for mobile, and in the past few months, we've location-enabled other applications from third parties and Google. Hundreds of location-enabled iPhone applications, including the Google Mobile App, use Google's database of cell towers to determine approximate location. And just last week we announced Mobile Search with My Location, powered by the Gears Geolocation API.

With today's launch, your location estimate will be centered closer to your true location, and we have also improved the calculation of just how good our estimate is. When we originally launched the "blue circle" on Google Maps for mobile, the circle usually stayed the same size no matter if you were in downtown Manhattan or rural Iowa. Now, the next time you're using Google Maps in downtown Manhattan, expect to see a much smaller circle that's also far more accurate. Conversely, when you're in a lightly populated area like rural Iowa, expect to see a much larger circle which also happens to be centered closer to your true location. Check out these screenshots to get a better idea of the before and after effects of today's change:

New York City -- a smaller light blue circle denotes that we're more confident of your actual location.




Slater, Iowa - the light blue circle is larger because there are fewer cell towers with which to determine your location, but the dark blue circle is more accurately centered in downtown Slater


So how exactly have we made these improvements? Mobile operators typically need a lot more cell towers in populous areas to service all the users. This means each individual tower provides a much smaller coverage footprint. On the other hand, in a very sparsely populated area, towers provide much larger coverage footprints. We've developed algorithms to try and figure out what the right circle size should be and are pleased to make this available to you today.

There's actually nothing you need to do to start enjoying the new improvements to My Location. Any application powered by Google's geolocation service automatically benefits from today's launch. Enjoy!

Posted by Zhengrong Ji, Software Engineer