Radar accurately detects objects by transmitting electromagnetic waves, usually in the form of short pulses or continuous waves, from an antenna. These waves travel through space until they encounter objects in their path. When hitting an object, some of the radar energy reflects back to the radar antenna as an echo. The radar system receiver then captures and processes these echoes. By analyzing the time it takes for the radar pulses to travel to the object and return (known as time of flight), the radar calculates the distance to the object.
This process involves precise timing mechanisms and signal processing techniques that allow the radar to determine distances with high accuracy, even when distinguishing between multiple objects in its field of view.
Radar detects objects through the principle of echo going. When radar waves encounter an object, they reflect off its surface in all directions, including toward the radar transmitter/receiver. The resistance of the returned echo depends on the size, shape, material composition of the object, and orientation relative to the radar beam.
Radar systems are designed to detect these weak echoes amid background noise and interference, using sensitive receivers and sophisticated signal processing algorithms. Doppler radar, for example, not only detects echoes, but also measures the frequency shift caused by moving objects, providing additional information about their speed and direction of movement.
To determine the distance to an object, radar relies on measuring the delay between the transmission of a pulse and the reception of its echo.
This delay directly corresponds to the distance traveled by the radar pulse to the object and back. Radar systems use precise timing mechanisms, often synchronized with transmitted pulses, to accurately measure these time intervals. Knowing the speed of light, the radar calculates the distance to the object using the formula: distance = (delay × speed of light) / 2. This simple principle forms the basis of radar variation, allowing precise measurement of distances ranging from meters to meters to hundreds of kilometers, depending on the radar design and operational parameters