Behavior of Metal Objects in Radiation Fields

These articles address the remote sensing of metallic space objects at radar, infra-red, and visible frequencies.

This article (text, figures) summarizes the geometric optics limit of the interaction of electromagnetic waves with metals. The components of the description are a complex index of refraction that depends on frequency and conductivity, and the Fresnel equations describing the reflection and transmission of a monochromatic wave incident on a planar surface. From this follows a characterization of the heating and emissivity of metals at frequencies below the visible. I address the specific case of the heating and equilibrium of a metal surface exposed to earth and sun radiation fields. A follow-on calculation provides the perpendicular and parallel components of the emissivity of a metal.

This article addresses in more detail the thermal, emissive, and reflective behavior of spheres in earth and sun radiation fields. Three different emissivity models are considered. Specular and diffuse reflection are considered, as are point and extended sources.

This article develops a description of radar cross section in the physical optics limit. Analytical expressions are developed for the radar cross section of various simple shapes.

This article describes the electrical properties of the fair weather atmosphere and considers the possibility of electrical discharge on moving objects. It is a fun introduction to the global electric field in which the surface of the earth and the ionosphere form the two plates of a global capacitor.