Final answer:
GPS receivers calculate an exact position by detecting signals from at least four satellites and computing the travel time of those signals. This process requires precise synchronization of satellite clocks, taking into account special and general relativity to achieve accurate location determination.
Step-by-step explanation:
To determine a location, GPS receivers need to perform two critical functions to calculate an accurate position:
- Detect signals from at least four overhead satellites.
- Calculate the receiver's position based on the time it takes for those signals to reach the receiver.
GPS technology relies on an array of 24 satellites that orbit the Earth, each equipped with precise atomic clocks. A GPS receiver utilizes the timestamps from these signals to compute its exact position. GPS satellite signals travel at the speed of light, and the time taken for these signals to reach the receiver is used to determine location with high accuracy. In fact, the clocks must be synchronized to a precision that accounts for relativistic time dilation effects, as even the minuscule time differences due to the speeds of the satellites and their different gravitational potential relative to that on Earth's surface can lead to significant errors in location determination. Therefore, both special relativity and general relativity are accounted for in GPS signal processing.