What is the difference between active radar and passive radar?
Active radar involves transmitting radio waves from a radar transmitter and receiving reflections or echoes from objects in the environment. It actively emits signals and measures the delay and Doppler shift of reflected signals to determine the distance, direction and speed of targets. In contrast, passive radar detects and tracks objects by analyzing signals unintentionally emitted by other sources, such as commercial radio or television broadcasts, without emitting its own signals.
Passive radar systems rely on these ambient signals to detect targets, providing stealth and emissions reduction advantages over active radar systems.
Active homing refers to a homing system used in missiles or other projectiles where the missile actively emits a signal, such as radar or infrared, to detect and be home on its target. It actively seeks and locks onto the target using its own emitted signals for guidance. Passive housekeeping, in contrast, involves guidance systems that rely on signals from the target itself or other ambient sources of tracking and guidance.
It does not emit its own detection signals but rather houses on emissions or signals naturally emitted by the target.
Passive radar is used primarily for surveillance and tracking purposes without emitting detectable radar signals. It takes advantage of signals from existing radio frequency sources, such as radio and television broadcasts, to detect and track targets such as aircraft, ships and vehicles. Passive radar systems provide advantages in stealth and covert operations by avoiding active radar emissions that could be detected by adversaries.
They are used in military applications for situational awareness, border surveillance, and surveillance of airspace and maritime activities.
Active jamming involves deliberately transmitting jamming signals to disrupt or interfere with enemy radar, communications, or navigation systems. It actively emits signals to overwhelm or deceive radar or communications receivers, causing interference and preventing accurate detection or communication.
Passive jamming, on the other hand, uses techniques such as bullets or decoys to passively reflect or scatter radar signals, create false targets, or reduce the effectiveness of radar systems. Passive jamming does not emit its own jamming signals but rather exploits the radar environment to deceive or degrade the performance of enemy radar systems