The map is the last step
A GPS receiver listens to satellite signals carrying timing and orbital information. Comparing when a signal was sent with when it arrived helps estimate a distance. Several such measurements, together with satellite positions, allow the receiver to solve for its location. The map application then places that calculated location on a map; the satellite is not sending a ready-made photograph of your street.
Why the clocks matter
Signals travel at approximately the speed of light. The satellites carry atomic clocks, while the receiver must account for its own clock offset. A conventional three-dimensional GPS solution uses at least four satellite measurements to solve for three position coordinates and the receiver’s time offset. The four unknowns are the key idea. Additional measurements can support a better solution, but satellite geometry and measurement quality still matter.
Turn time into a range error
Light travels 299,792,458 metres per second in vacuum. Multiply by one nanosecond—one billionth of a second—and the result is 0.299792458 metres, or about 30 centimetres. At 100 nanoseconds, the equivalent range difference is about 30 metres. The slider demonstrates that conversion for a single signal. It does not convert timing error directly into the same-sized horizontal error on a map.
The real world is not an empty vacuum
Atmospheric effects, blocked signals and reflections can affect a receiver. Geometry determines how range uncertainties influence the estimated position, and receiver processing also matters. The explorer isolates the arithmetic of time and distance; it does not simulate a full navigation solution or promise a device’s accuracy. That distinction explains why excellent satellite clocks and a poor position fix can coexist. The engineering challenge is to preserve timing information and interpret several imperfect measurements together.
Sources & further reading
Sources checked 14 November 2026. Educational models are labelled with their assumptions. These organisations do not endorse this website.