Field Guide · hardware

Also known as: GNSS receiver

A GPS receiver determines a device’s position by timing radio signals from a constellation of navigation satellites, yielding location, speed, and a very precise time reference.1

Overview

The receiver listens for the faint signals of satellites overhead and, from the time each took to arrive, solves for its own position — needing a clear sky view and signals from at least four satellites for a 3D fix. Modern chips are GNSS receivers, combining the US GPS system with GLONASS, Galileo, and BeiDou for faster, more reliable fixes.2 In a phone the GPS block sits in or beside the SoC, with its own antenna, and often takes hints from the cellular modem (assisted GPS) to lock faster.

Where it fits

Location is the killer feature GPS adds to phones, smartwatches, and wearables — maps, fitness routes, geotagging. Its precise one-pulse-per-second timing is also valuable beyond navigation: a GPS-disciplined clock can give an SDR setup like GopherTrunk an accurate frequency and time reference, useful for stable tuning and for timestamping decoded calls across distributed capture nodes.

Sources

  1. Satellite navigation — Wikipedia, on GNSS positioning. ↩

  2. Global Positioning System — Wikipedia, on the GPS system specifically. ↩

See also