Application of the MEI method to wave propagation predictions over irregular terrain

Electromagnetic wave propagation over hilly terrain is important in point-to-point communication over land, ground-to-air communication, PCS network design, etc. Janaswamy (1992) developed a numerical model for propagation predictions using the MFIE. Although the method could include all effects of wave propagation, a principal limitation of the method was the requirement of large computer resources. This was particularly true for electrically large terrain irregularities. The present authors use finite differences in conjunction with the the measured equation of invariance (MEI) [Mei et al., 1992] method to develop a computationally efficient model of wave propagation of two dimensional fields over an irregular, inhomogeneous terrain. Magnetic field, H/sub x/, generated by a TE/sub x/ line source is represented in an integral form in terms of the field, H/sub 0x/, over a flat, constant impedance plane, and the field scattered by the terrain irregularities and inhomogeneities. The MEI method is used to terminate the computational domain. Numerical results are presented for the ground wave as well as the sky wave, both for convex and concave geometries.