The interpretation of radar echoes from meteor trails

Electromagnetic-wave theory is applied to various cylindrically symmetric distributions of electron density to ascertain the dependence of reflected radio signals upon the system parameters. Results are expressed in terms of the average effective dielectric constant, the circumference/wave-length ratio of the cylinder, and the incident wave polarization. Two models have been mainly considered—a linear radial variation of electron density, and a constant density distribution. The general properties and dependences of the echoes are summarized for each major region of trail parameters, and the transitional characteristics are indicated. A qualitative comparison of these results with published observational data leads to a new picture of the trail decay period.