The output• Coords – latitude, longitude, altitude, accuracy, altitudeAcc uracy, heading, speed, verticalSpeed• Address – country, region, county, city, street, streetNumber, premises, postalCode• timestamp
What makes it complex?
Triangulation/forward link examples• GPS – Accuracy about 10m – Does not work indoors• Wi-Fi – Accuracy about 20m – Works indoors• Cell tower – Accuracy depends on cell coverage
Geo IP example• Mobile phone ip address is ephemeral?• Latency and traceroute information
Social network example• likelihood of friendship with a person is decreasing with distance• Your friend shared location with GPS• Your friends profile has an address Good enough for marketing, goodcomputational performance and increasedlocation probability when used with geo IP
Search query analysis exampleWWW 2008 / Refereed Track: Search - Query Analysis April 21-25, 2008 · Beijing, China F i gur e 8: Spher es of i nﬂ uence of basebal l t eam s.
References• Spatial variation in search engine queries, www2008, L. Backstrom, J. Kleinberg, R. Kumar, J. Novak• Find me if you can: improving geographical prediction with social and spatial proximity, www2010, L. Backstrom, E. Sun, C. Marlow,• Uses of W3C’s geolocation API, CINTI 2010, B. Pejic, A. Pejic, Z. Covic• The locative Web, locweb2008, E. Wilde, M. Kofahl