信号伝搬とターゲット

Propagation environments have significant effects on the amplitude, phase, and shape of propagating space-time wavefields. In some cases, you may want to simulate a system that propagates narrowband signals through free space. If so, you can use the phased.FreeSpace System object™ to model the range-dependent time delay, phase shift, Doppler shift, and gain effects.

A two-ray propagation channel is the next step up in complexity from a free-space channel and is the simplest case of a multipath propagation environment. The free-space channel models a straight-line line-of-sight path from point 1 to point 2. In a two-ray channel, the medium is specified as a homogeneous, isotropic medium with a reflecting planar boundary. The boundary is always set at z = 0. There are at most two rays propagating from point 1 to point 2. The first ray path propagates along the same line-of-sight path as in the free-space channel (see the phased.FreeSpace System object). The line-of-sight path is often called the direct path. The second ray reflects off the boundary before propagating to point 2. According to the Law of Reflection , the angle of reflection equals the angle of incidence. In short-range simulations such as cellular communications systems and automotive radars, you can assume that the reflecting surface, the ground or ocean surface, is flat.

Model targets with fluctuating and nonfluctuating radar cross-sections.