Lichtinterception

Lichtinterception is the process by which light from a source is intercepted by matter, resulting in attenuation, redirection, or alteration of the original beam. The concept is used across optics, atmospheric science, and solar energy studies to describe how much light is available at a target surface or within a system after interaction with intervening material.

Interception occurs through absorption, scattering, reflection, and, in some cases, refraction. The fraction of light intercepted depends on geometry (relative positions and angles of source, surface, and observer), surface properties (roughness, albedo, refractive index), and the spectral composition of both light and material. In canopies or layered media, the interception also depends on the distribution of matter along the light path.

Quantitative descriptions often use the Beer–Lambert law for simple absorptive media, with transmitted intensity I = I0 e^{-αx} and intercepted fraction f = 1 − e^{-αx}. In more complex settings, optical depth τ = ∫ κρ ds and radiative transfer equations are used. In architectural and solar-thermal contexts, view factors and shading analyses estimate interception of daylight or solar radiation.

Applications include daylighting design in buildings, optimization of solar panels, crop light-use studies in ecology, and the calibration of radiometric instruments. The term is related to photon attenuation, radiative transfer, and shading analysis, and is often considered together with transmission and reflection in a complete description of light–matter interaction.