Ranging signals are transmitted by GPS satellites to allow the receiver to determine which measurement?

• A. Speed of the receiver.
• B. Range (distance) to each satellite.
• C. Altitude above earth's surface.
• D. Antenna orientation.

Answer: (B)

The main idea is that GPS ranging signals are used to measure the distance from the receiver to each satellite. Each satellite transmits a precisely timed code, and the receiver correlates with that code to determine how long the signal took to travel from satellite to receiver. Multiplying the travel time by the speed of light yields the range to that satellite. Having ranges to at least four satellites lets the receiver solve for its three‑dimensional position and its own clock bias, which is essential for accurate positioning. The other options aren’t obtained from the ranging signals: speed is usually inferred from Doppler shifts, while altitude and antenna orientation aren’t determined directly from these range measurements.