Updated at 12:30 p.m. on September 9, 2008 with more details about Google Maps' location accuracy.
This week, Google's mobile team let loose with an updated version of MyLocation, a feature of Google Maps that geolocates your position based on cell-tower triangulation. It fixes a minor, but distinct drawback: an overly generous target.
MyLocation, which launched about a year ago, was the first implementation of its kind we've seen for a mobile app, and it gave a taste of GPS to users whose low and midgrade phones were without it--the majority of the cell-phone-owning population. However, the best MyLocation could do was inscribe you on the map within a mile radius of your actual presence. Not bad when you compare it to the entirety of global geography, but not as precise as you'd like if you're, say, on foot in bustling New York City.
Google promises that the blue bubble mapping your location will become more precise, shrinking in size if you're amid dense population. In the way of specifics, Google's knowledge of mobile towers lets the map application nail down your location relative to your position among the cell towers. While that's nothing new, improvements to Google's cell-tower database directly informs accuracy, so the more towers its got in the system, the smaller the circle can be and the closer its center will be to where you've planted your feet. "At present," says a Google spokesperson, "in urban areas, MyLocation frequently broadcasts your location within one-third to one-half a mile of accuracy.
The improvement is mostly a unidirectional benefit for the urban populace--in rural locations where more people are served by a single tower, the MyLocation bubble will still cover more ground, though the placement of the circle's center should drift toward your true position.
With cell tower information, Google uses various algorithms to approximate a user's handset location relative to the cells nearest to him or her. The accuracy of this information depends on how big an individual cell is. So, areas with a denser concentration of mobile towers allow for a more accurate My Location reading. And as our database of cell locations continues to improve, so too will the accuracy and coverage of the My Location feature. Today, we frequently show 1/3- to 1/2-mile accuracy in urban areas."
This enhancement works nicely with Google's recent release of the new Google Mobile App for BlackBerry, but since it's Google, the API change also affects the gazillion iPhone applications that outsource location details to Google's maps.