This is the second post in our Making of Maps series. Here you’ll get a glimpse of the information we use to build Google Maps from authoritative sources and our own mapping tools. —Ed.

With Google Maps by your side, you have a co-pilot for everything from turn-by-turn directions, to discovering new restaurants to deciding which hiking trails to climb next. This is possible in large part because Google Maps includes information from thousands of authoritative sources as varied as the U.S. Geological Survey, the Ordnance Survey of Ireland, and Mexico’s National Institute of Statistics and Geography (INEGI). But even all this isn’t enough to build the most comprehensive map. To give you the highest quality results, we need to fill in details like the right place to turn on an unmarked road and indoor maps of your local museum.

Over the years, we’ve created new sources of information to fill in those details. In fact, one of the most important sources for Google Maps is our own Street View imagery. In addition to giving you a way to virtually explore the world, Street View has helped to improve the quality of what we call our “basemap.” With ground-level images, we can identify one-way roads, pinpoint addresses on the map, and verify street names. This added level of detail gives you better search results, more accurate directions, and smoother turn-by-turn navigation.

Adding and verifying street names and turn restrictions in Taipei City, Taiwan

But Street View isn’t the only way we fill in details on Google Maps. Today, we’re releasing six indoor maps created with our new mapping tool called Cartographer. Cartographer is a backpack equipped with Simultaneous Localization and Mapping (SLAM) technology.

The Cartographer creates indoor floor plans on the fly

As the backpack-wearer walks through a building, SLAM technology generates the floor plan in real time and displays it on an Android tablet connected to the backpack’s computer. The wearer can then add points of interest on the go, such as a T-rex replica in a museum. As fast as you can walk, you can map with Cartographer—so you can create floor plans for a 39-story building, like the San Francisco Marriott Marquis hotel, in just a few hours!

Deutsches Museum in Germany features aircrafts and helicopters in historic hangars

Projects like these make Google Maps unique. Our own mapping tools supplement the information from authoritative sources, making it easier for you to get where you need to go.

But the world is big and changes happen every day—businesses open and close, roads go under construction, and new parks are built. You know your neighborhood and what’s important to your local community better than anyone, which is why we created a tool called Map Maker that empowers anyone—from the avid mapper to the traveling businesswoman—to update the map as the world changes. Next up, we’ll talk to members of the Map Maker community to hear their stories. Until next time!