Google has introduced an interesting solution to the problem of creating interior maps for malls, stores and so on, to use in Google Maps. The company debuted interior maps a few months ago, but it required it to work directly with the places being featured.
Later, it started allowing business owners to upload floor plans
for their places and have them converted to an interior map that works with the Google Maps Android app. But even this required quite a bit of work, from the business owners and from Google.
Now it's introducing an even easier way of creating an accurate interior map, but more importantly, of providing accurate directions inside buildings, the Google Maps Floor Plans Maker app
"If you’ve uploaded a floor plan through the Google Maps Floor Plans tool, once you install the Google Maps Floor Plan Marker app, you’ll be guided through the process of walking around the entire surface area of your place of interest," Google explained
"Using the app, you collect data from sources such as GPS, cell tower, and publicly broadcast WiFi information that can help us make the My Location feature’s familiar 'blue dot' icon accessible for Android users when they’re inside the venue," it added.
Google determines location from a number of sources. The most accurate, but also the most prone to interference is GPS, which works poorly in cities and doesn't work at all inside.
Cell towers can also be useful, a device's location can be determined fairly accurately by triangulating its position from the signal strength. Finally, WiFi routers can be used, in the same way as cell towers, to determine a location, but they're the last option since their own location is harder to pinpoint.
All of this works well enough outdoors, but it gets even more complicated inside. Which is why Google is asking business owners to record signal strengths in their venues.