Decision Making in Airborne Surveillance Radars Employing an Electronically Scanned Antenna

In radars employing an electronically scanned antenna, the direction of the electromagnetic beam can be changed instantaneously, without being constrained to a mechanical motion of the antenna. The traditional revolving or repeating measurement patterns can be relaxed, leading to greater flexibility. It is assumed that the performance of the radar system can be improved by exploring this flexibility. Although it is easy to come up with ideas of how to use the flexibility, the design of a controller for such a system is a difficult task. The antenna can be regarded as a resource, which is time shared among all measurement tasks of the radar system. A measurement task is for instance tracking a target, or searching a sector for new targets. As in all time shared systems, there is a resource constraint, i.e. the scheduled time can not exceed the available time. If we decide on an increased share of resources to one of the tasks, some other task may have to be sacrificed. Thus, the exploration of the time shared properties must be done with care. In this report, the theory of decision-making is studied and applied to control problems of a time shared, airborne, surveillance radar. The main contribution is that many concepts in the field are discussed, in particular the concepts of decision-making. Also, an optimizing resource controller of a surveillance radar is built. The design is based on abstraction and modularization of the decision-making process. This reduces the number of parameters involved in each decision-making situation, and makes complexity manageable. Some models and measures useful in decision-making concerning resources are discussed separately. A case study of track initiation is included to illustrate the concepts of decision-making in radar control.