A review of recent developments in radar signal processing in the presence of clutter is presented, with particular reference to an air-traffic environment. Two different signal processing issues are considered. The first issue relates to the adaptive suppression of clutter (of unknown statistics) and consequent enhancement of the echo produced by a moving target (e.g., aircraft). Here, several adaptive techniques are presented to respond to changes in environmental conditions. The second issue relates to the problem of identifying the sources of clutter with the aim of vectoring aircraft around hazardous areas. In both cases, results based on real-life radar data are presented to support the theory.