So THAT’S how my phone knows where I am!
summary
Phone location is traced to timestamps from spaceborne clocks and simple geometry not magic: devices compare satellite timestamps from about 24 satellites to compute distance and need three (plus one for clock error) to fix position, so line‑of‑sight or multipath in urban canyons explodes error from ~15–20 m to ~100 m while here the system gets 2–3 meters accuracy. Practical fixes mentioned include ground correction servers, Wi‑Fi and cell tower aiding, Bluetooth beacons and fingerprinting, 3D building models for side‑of‑street fixes, and deployed prototypes that demonstrably improve accuracy.
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chapters (8)
- 0:00Start
- 0:20Computational Flener
- 0:52Urban Canyons
- 1:52The Age of Exploration
- 2:29Dead Reckoning
- 3:26The Marine Chronometer
- 4:38The Cold War
- 7:54Indoor Location
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