How does GPS work in navigation?

GPS, or Global Positioning System, operates by utilizing a network of satellites orbiting the Earth. These satellites continuously transmit signals containing precise time and positional information. A GPS receiver on the Earth's surface collects signals from multiple satellites and uses the time delay of the received signals to calculate its own geographical location through a process called trilateration.

The key aspect of this system is the interaction between the satellites and the receiver. By triangulating the signals from at least four different satellites, the GPS receiver can accurately determine its 3D position (latitude, longitude, and altitude), as well as the precise time. This process allows for very accurate positioning and navigation across various applications, such as in vehicles, smartphones, and other navigational equipment.

The other options do not accurately describe how GPS functions. A single terrestrial station would not provide the global coverage needed for GPS, and underwater cables are not relevant to satellite-based positioning. Similarly, while a magnetic compass provides directional guidance, it does not contribute to the precise positional data that GPS offers.