Radar is a set of advanced, intelligent, Wireless-Intrusion-Detection-Service-Wireless-Intrusion-Prevention-Service (WIDS-WIPS) features that are integrated into the Wireless Controller and its access points (APs). Radar provides a basic solution for discovering unauthorized devices within the wireless coverage area. Radar performs basic RF network analysis to identify unmanaged APs and personal ad-hoc networks. The Radar feature set includes: intrusion detection, prevention and interference detection.
Definition as per the manual. Hope this helps.