Google Maps - Lars Rasmussen

Google Maps has a new branch in Darling Harbour, Sydney.

GM has about 500 million squares. Within weeks they hope to have high res of Sydney; once or twice more zoom over the current even. Zachary's pizza, Berkeley is Lars' tip for best Pizza in the world.

Originally was a C++ browser with Where2. They took it to Google who said they liked the web. They tried plugins/flash. With AJAX it was 4 weeks for prototype; as opposed to years for C++ app. Javascript has inconsistencies across browsers, but compared to C++ across OS it is easy. However, compared to Google Earth it is nowhere near as rich in features.

On the first day hit top load they predicted for 6 months. Satellite imaging caused traffic to grow exponentially in one day.

Their design philosophy

  • end-user is royalty
  • go beyond browser lowest-common-denominator : because they're Google browser people ask them what they want.
  • dynamic as native apps; simple as google website
  • do what it takes
  • launch early + often : with 4 months dev, figure 3 months to launch. Larry Page played with demo and said "just go". labs.google.com playground.

Now under Google local. They listen to feedback; they discussed frame layout endlessly for the merge; launched and people hated it, changed in a week.

DHTML overview : javascript handles events, which can modify the structure of the page. browser does nothing until event handler finishes, then re-renders the page off screen and displays it.

Back-button was solved with virtual pages. What does it mean to push the back button? Back should go back through search history, not random junk. Normally the browser remembers clicks in iframes as history. To get around this you use a "virtual" iframe which copies what is happening into a main page. this way you can control the pages that are shown and consequently the back bar.

Backend map providers got nervous about hacks. housingmaps.com had inadvertently broken a link back to the data provider so Google weren't weren't being charged. API wasn't a technical challenge, but a contractual one. Google loved the maps hacks but couldn't tell anyone.

Google would never build a bus map route for Seattle, but they are inspired by it. Google watches the api key to see what cool things are happening. Katrina imagery request was from the government. If you want a job write a good maps hack.

Growth areas is mostly about integrating all of Googles data sources.

Cafe in san-fran? 20 billion web pages that probably can tell you where "Silicon Valley" is, but Google maps doesn't know. User logs show that users think google knows that stuff -- maybe comes from the "know it all" search box which people think can do anything.

Processing : different data and different confidence; can you join it? API is telatlis(?) data ... navtech data is on the site. can they merge? can they merge other databases? adding spacial infrastructure to google search infrastructure. "cheapest gas via work"

Routing: shortest path algorithm with weighted graph. If underlying data is correct works fine. However traffic not taken into account; taxi driver berated him that maps takes him straight into traffic -- some drivers love it because tourists bring it and they make money. Ridefinder -- nobody uses it but you get gps feeds from taxi drivers which you can use to re-weight your maps.

Drawing: pretty anti-aliased is nice. Others have had to catch up

Questions: When is Sydney maps coming? They are very tied to data format ... and Sydney maps don't' come in that format. working to remove that, early next year. where can you get Aussie map data? sensis, map data sciences. all comes from the government in some form.

Different grid systems around the world? No cartographers on the team really. In japan, use different datum; lat/long use different views of ovalness of the earth. datums need to be normalised.

How make money? Haven't settled on that just yet. Google figures users == money; not sure how but something will come up. Advertisements is obvious for "local search" stuff.

API via c++? no, web is focus.

Satellite tile age? higher == fresher. Google Earth looks after imagery; new Sydney about 6 months. Imagery has a "novelty" feel; big hits when first released but users don't always come back.

Censorship of photos: have to respect.

Obfuscated javascript? makes code smaller. time to download is now in seconds, needs to be milliseconds.

Government fudging? Not that he knows about ...

Projections of tiles? New different ones on the way, maybe. Night satellite, etc. winter/summer etc. geological features, historical maps. Have the data any maybe one day.

Disputed borders: no easy answers. Chinese laws say you can't move maps out of the country; but they do have maps on servers in China. Might have to present different things to different users.