Threat simulation in electronic warfare training requires both signal fidelity and tactical realism. These aspects of simulation are generally not in conflict. However, as tactical realism is increased - through the use of autonomous tactics models responsive to simulated ownship position and crew countermeasures - training value can be compromised. Specific problems can include: inability to "schedule" the hostile signal environment to avoid trainee overload or to present very specific signal combinations; loss of insight into exactly what situation confronted the trainee at any given moment; and loss of repeatability in a given mission, hence loss of the ability to deliver equivalent, objective-oriented training to successive trainees.
Modern training systems must balance these issues to assure the development and maintenance of superior skills in the electronic combat community. This paper describes the tradeoffs to be considered in the design of threat libraries, selection algorithms, and tactics models, it further indicates approaches to be considered as a function of purpose of the simulation and the level of training to be delivered.