Since the end of the Cold War it is widely perceived that the main theatre of naval operations has shifted from open ocean to littoral regions. These regions pose difficult problems for surveillance radars, due to the different characteristics of land and sea clutter. For example, if a cell-averaging (CA) CFAR window passes from sea to land over a sea cliff, or some other topographical feature with large radar cross-section, then the CFAR algorithm may yield an unacceptably high number of false alarms due to the large and abrupt increase in clutter power. If the same CFAR window were to pass in the opposite direction, from land to sea, then the CFAR output can exhibit a 'blind zone' of degraded detection performance in the coastal water, due to slow threshold adaptation. In this paper, which is a development of earlier work by the authors, these and other problems are investigated. Firstly we describe how we create a synthetic environment to test CFAR design, and how CFAR performance depends upon environmental and target parameters. (This work forms part of the ARES [Airborne Radar Environment Simulation] software suite under development at BAE SYSTEMS, which provides scenarios against which airborne radar detection and tracking algorithms are tested.) Secondly we demonstrate CFAR algorithm performance when applied to real littoral data.
展开▼
