Where the Heck Am I? Understanding Location in Your Application
summary
Explains how satellite navigation actually fixes a phone: a constellation of 25 satellites in six orbits at ~20,000 km broadcasts ephemeris and almanac data, receivers need signals from at least four satellites to solve position and clock offset, almanac download can take 12.5 minutes without assistance, assisted GNSS (AGPS) speeds that up, real-world accuracy is about 5 m in ideal conditions and degrades with reflections and ionospheric delay, and Android exposes raw measurements via Android location.gnssmeasurements.
AI-written summary · about
chapters (8)
- 0:00Introduction to location importance
- 3:51History of GPS development
- 9:27Understanding latitude and longitude
- 13:17How GPS satellites work
- 18:50Trilateration and satellite positioning
- 24:10Measuring distance to satellites
- 28:49GPS accuracy limitations
- 34:47Other GNSS systems overview
related talks
50mDo you know where you are? How satellites keep us from getting lost
47mThe 20,000km view: How GPS works
39mHow to get one-meter location-accuracy from Android devices
17mGlobal Positioning System
19mLoRa Geolocation
24mEuropean Satellite Navigation Systems
36mSeamless and Smooth Location Everywhere with the new FusedLocationProvider
15mBluetooth® Technology Introduction: Exploring Major Recent Advancements