What does RADAR stand for?

RADAR stands for "Radio Detection and Ranging." This term is used to describe a technology that employs radio waves to identify the distance, speed, and other characteristics of objects, such as aircraft or ships. The system sends out a radio signal that bounces off objects and returns, allowing the system to calculate distance based on the time it takes for the signal to return.

The terminology highlights both the detection aspect, whereby the presence and movement of objects are reported, and the ranging aspect, which refers to the measurement of their distance from the radar source. This foundational understanding of radar technology is crucial for various applications, including military operations, air traffic control, and meteorology, where accurate detection and distance measurement are vital.

The other options do not correctly define RADAR and instead present alternative phrases that do not accurately reflect its function or purpose within radio technology.