Constant false alarm rate - or CFAR - is easily one of the most well-known radar detection algorithms.
This is due in part to its simplicity if implementation and relative effectiveness over using a static threshold or getting just saying the maximum values are the targets. It can also be used on different measurement types, and even in multiple dimensions (e.g., range, Doppler velocity, 2D range-Doppler spectrum).
In this video I go over the motivation, implementation, and some of the design knobs available when using CFAR.