Advanced Refractive Effects Prediction System (AREPS)

Since 1945, the Atmospheric Propagation Branch of Space and Naval Warfare System Center, San Diego and its predecessor organizations have provided a full spectrum research and development program, rapidly responding to critical fleet EM propagation requirements and deploying systems to address these requirements. From an urgent military operational requirement for propagation modeling within a terrain effects dominated environment, we developed the Advanced Propagation Model (APM), a hybrid ray-optic and parabolic equation (PE) model that uses the complimentary strengths of both methods to construct a fast, but yet very accurate composite model. Using its full hybrid mode, APM has proven to be much faster than PE models alone, with overall accuracy at least as good as the pure PE models. With its airborne sub-model, APM can solve problems for very high elevation angles, where PE methods would not normally be used.