Radar Wave Propagation

Chapter 8 Radar Wave Propagation In the earlier chapters, radar systems were analyzed with the assumption that the radar waves that traveled to and from targets are in free space. Signal interference due to the earth and its atmosphere was not considered. Despite the fact that “free space analysis” may be adequate to provide a general understanding of radar systems, it is only an approximation. In order to accurately predict radar performance, we must modify free space analysis to include the effects of the earth and its atmosphere. This modification should account for ground reflections from the surface of the earth, diffraction of electromagnetic waves, bending or refraction of radar waves due to the earth’s atmosphere, Doppler errors, rotation of the polarization plane (Faraday effect), time delays, dispersion effects, and attenuation or absorption of radar energy by the gases constituting the atmosphere.