An Interactive Explanation of GPS (2022)

a year ago

GPS is a crucial invention of the late 20th century, enabling precise location tracking for ships, airplanes, cars, and hikers.
GPS relies on satellites orbiting Earth, which are part of a larger system that includes ground control stations and receivers.
The system uses trilateration, measuring distances from multiple satellites to determine a receiver's position and time bias.
GPS satellites operate in specific orbits with precise timing, corrected for relativistic effects due to their speed and altitude.
The navigation message from satellites includes data like clock corrections, ephemeris (orbital parameters), and almanac (coarse data for all satellites).
Signal propagation is affected by atmospheric conditions, requiring receivers to account for delays and ignore low-elevation signals.
GPS signals use binary phase-shift keying and pseudorandom noise codes to distinguish between satellites and decode data amidst noise.
Receivers correlate incoming signals with known codes to determine time offsets, enabling precise time-of-flight measurements.
The system's accuracy is enhanced by using data from multiple satellites, improving position and time calculations.
GPS technology integrates advancements in rocketry, atomic clocks, radio transmission, and microchip technology.

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