Google Earth on 48 screens

Back in 2009, Google developed the first Liquid Galaxy, an entirely new way to display Google Earth on eight screens – which creates an immersive experience of virtually flying around the globe. Since then, we’ve built dozens of Liquid Galaxies all over the world and open sourced the code so anyone can build their own.

Late last year, the Paris Center for Architecture and Urbanism: Le Pavillon de l’Arsenal, approached us asking if they could use Google Earth to power a new interactive display highlighting the Paris metropolitan area in 2020 with upcoming buildings in 3D. Naturally, we were excited about the project, especially when they shared that the display would be 40 square meters – posing a fun and unique challenge.

A year later, we are excited to share that the first 48 screen Liquid Galaxy is now on display in Paris. We believe this to be the largest screen showing Google Earth to date!

Photo: Vincent Fillon
What started as a 20% project to support the new Google Cultural Institute resulted in a stunning display of the Earth in almost 100M pixels – powered by 48 instances of Google Earth synchronized and operated through 4 multi-touch screens with pinch and zoom functionality. The view is even sharper due to a refresh of the entire Paris area with higher resolution imagery.

As a Parisian, it’s amazing to be able to see what the city will look like in the future. If you can’t make it to France in the near future, you can preview it at home by downloading this KML file and opening it in Google Earth.

The Canopy and Transport Hub: Patrick Berger and Jacques Anziutti architects
This project was a close collaboration between Google and Le Pavillon de l’Arsenal, as well as technology JCDecaux, End Point and design partners ultranoir.

Over the next few months we’ll be fully open sourcing this work on Liquid Galaxy, as well as the graphical interface. Keep an eye out on our source code page for updates.


Every year in Boston, parents navigate the school selection process in an effort to get their kids into the best possible public schools. The process is complicated, and, depending on the outcome, can leave parents feeling frustrated and confused. DiscoverBPS was designed to make the process more intuitive, and to help parents make better choices for their kids.

Iteration #1 – Geocoded Addresses

In our first iteration, we used a home address and grade level to identify a student’s eligible schools, and then displayed the results on a map. In the screenshot below, the green circle represents the student’s “walk zone” (in this case, a 1.5 mile radius appropriate to a 7th grade student), the yellow polygon represents the North Assignment Zone, and the markers represent the schools.

With a little help from Google’s Geocoding and Maps APIs, we seemed to be well on our way!

On closer inspection, however, we noticed one school that fell just outside of the walk zone boundary, even though – after zooming in and switching to satellite view – the school campus was clearly overlapping with the walk zone:

Obviously, if our goal was to build a tool to make the process more intuitive, we needed to avoid introducing new ambiguities into the system.

Iteration #2 – School Parcel Shapefiles

To solve the overlap issue, we obtained shapefiles for all of the City’s school properties, and used a PostGIS-enabled database to calculate distances between the home address and the nearest point on the school parcel. In so doing, we were able to calculate walk zone distances, which allowed us to properly identify schools with walk zone eligibility:

After a several weeks of deep-diving into the internals of PostGIS mapping, we seemed to be back on track.

Stepping back, however, a new consideration came to light: was it fair to assume that a 7th grader could walk from downtown Boston, across the Charles River, and to a school in Charlestown in less than 1.5 miles? A Google Directions search suggested otherwise (the route below is estimated at 1.9 miles):

If the purpose of the walk zone policy was to determine which schools a student could reasonably get to on foot (and to discourage parents from busing their kids to schools on the other side of town), our walk zone circle began to seem misleading.

Iteration #3 – Walkshed Mapping

In the end, we decided to use an open source project called pgRouting (which extends PostGIS to provide geospatial routing functionality) along with OpenStreetMap to derive a “walkshed” polygon and to calculate street walking distances. We also could have used the Google Maps Distance Matrix API to calculate walking distance, but opted to go with pgRouting based on the need to create the walkshed polygon. These tools allowed us to then visualize the walkshed in Google Maps:

Aside from being noticeably smaller than the walk zone circle, the walkshed conveys a representation of walkability that is customized to the home address. Notice how the walkshed area is confined by bodies of water that are not spanned by any bridges.

DiscoverBPS is now live at The walkshed map (which would require policy changes by Boston Public Schools) is being considered for use in 2013.

The Philippines hosts a Maps for preparation of natural disasters

This summer, a group of Filipino mapping enthusiasts organized an impressive series of Google MapUps throughout the Philippines. The events brought together Google Map Maker mappers across the country to map their communities in preparation of natural disasters. Located in the western Pacific typhoon belt, the Philippines is struck by an average of 20 tropical cyclones every year. As demonstrated by the 2009 Typhoon Ondoy (Ketsana) and Pepeng (Parma), which left much of Metro Manila underwater, the storms are both persistent and devastating.

The extensive series of Summer MapUps was organized by mappers from Luzon, Visayas and Mindanao after meeting at the Google Geo User Summit in Singapore. Following in the footsteps of super mapper Rally de Leon, who mapped extensively after the 2009 typhoons, this summer of MapUps was designed as a volunteer project for the Philippine Red Cross. The objective was to map places used during crisis, including health centers, government offices, gymnasiums and public schools used for evacuation.

All of the schools (left) and hospitals (right) in the Philippines, as mapped on Google Map Maker.
The events kicked off in the Mindanao region, with MapUps in Malaybalay, Bukidnon and General Santos City. Northern Luzon followed with a MapUp in the City of Pines, Baguio City. Baguio City was hit by a devastating earthquake a decade ago, which took the lives of over a thousand people. Volunteers wanted to make sure that they tagged important places, such as evacuation relocation sites, that would help in rescue and relief.

MapUps in Iloilo City, Metro Manila, Zamboanga and Cebu City followed. Zamboanga mappers focused on Zamboanga Peninsula, one of the least mapped areas in the Philippines. The Cebu City volunteer mappers were geology students from University of the Philippines Visayas Cebu College. They enjoyed tagging, moderating and editing data, and vowed to continue mapping to complete the Cebu map.


Even though summer is over in the Philippines, we will still continue to add map data using Google Map Maker as an effort to help the Philippine Red Cross. If you are interested in hosting a MapUp in your neighborhood, or have other great mapping ideas, be sure to visit Map Makerpedia, which brings together lessons, tutorials and use cases from around the world.