Noise in radar refers to unwanted random signals or interference that can degrade the quality of radar measurements or detections. It usually manifests itself as random variations in the resistance or disturbances of the received signal in radar data processing. Noise can come from a variety of sources, including thermal noise from electronic components, atmospheric disturbances, artificial interference, and unintended reflections or echoes.
In radar systems, noise can reduce sensitivity, limit detection range, and affect the accuracy of target measurements.
The source of radar noise primarily includes internal electronic components within the radar system itself. These components generate thermal noise due to their inherent random movement of electrons, which is proportional to their temperature.
This thermal noise contributes to the overall noise figure of the radar receiver and can affect the system’s performance in detecting weak signals or targets amidst background noise.
The noise figure of a radar receiver quantifies its ability to preserve the signal-to-noise ratio (SNR) of incoming radar signals. It is defined as the ratio of the signal-to-noise ratio at the receiver input to the signal-to-noise ratio at the output, after processing the signal through the receiver chain.
A lower noise figure indicates better performance, because it involves less SNR degradation from internal receiver noise sources. Radar receivers with lower noise figures can detect weaker signals more effectively, improving the sensitivity and range of the radar system.
Noise temperature is a concept used to describe the equivalent temperature of thermal noise power generated by a component or system.
In radar systems, noise temperature represents the hypothetical temperature of a resistor that would generate the same amount of thermal noise power as the actual electronic components in the radar receiver. It is measured in Kelvin (K) and provides a standardized way to compare and characterize noise performance on different radar components or systems. Lower noise temperatures indicate lower levels of thermal noise and better sensitivity of the radar receiver to weak signals or targets