What distinguishes coherent radars from incoherent radars?

Coherent radars utilize phase information of the received signal, allowing them to measure the radial velocity of scatterers with high precision. This capability stems from their use of a stable reference frequency, which enables the differentiation between the frequency of the emitted signal and the frequency of the reflected signal from the moving targets. As a result, coherent radars can perform Doppler processing, which is essential for determining how fast objects are moving toward or away from the radar. This is particularly beneficial in meteorology for detecting wind patterns and storm movements.

In contrast, incoherent radars primarily rely on the amplitude of the returned signals for detection and do not include phase information, which limits their ability to evaluate velocity. This distinction is crucial in radar meteorology, where understanding the dynamics of weather systems is essential for accurate forecasting and surveillance.