As the training industry converges on standards for Distributed Interactive Simulation, the next critical need is for better representations of electromagnetic propagation phenomena. Realistic radio simulation is essential for proper representation of command, control and communication functions. Accurate radar simulation is critical for the representation of various sensor and weapon systems for many types of platforms. Electronic countermeasures and counter-countermeasures must also be incorporated to adequately reflect the growing complexity of the modern battlefield.

This paper describes some electromagnetic propagation models that have been implemented for simulations commissioned by the U.S. Army Communications-Electronics Command (CECOM) and the Defense Advanced Research Projects Agency (DARPA) and discusses the "lessons learned" from those efforts. An approach for the efficient computation of radar intervisibility and target detection is described. Finally the DIS protocol extensions that will be needed to support and extend these models are discussed.