This document describes the system performance and interoperability requirements for non-cooperative UAS detection systems in airport environments. The document is intended to summarise the different aspects of the Counter UAS (C-UAS) system and to have a better understanding of the C-UAS system components at the detection level. This document will identify performance requirements parameters of the Counter UAS detection system as it has been defined in the ED 286 / DO-389 Operational Services and Environment Definition (OSED) for Counter UAS in Controlled Airspace.