Beam attenuation coefficient from absorption and scattering.

The beam (total) attenuation coefficient is the sum of the absorption and scattering coefficients, \(c = a + b\) (Johnsen 2012, ch. 5). It governs how a collimated beam — and the contrast of a sighted object — fades with distance, and is always larger than the diffuse attenuation \(K_d\).

Usage

beam_attenuation(absorption, scattering)

Arguments

absorption

Absorption coefficient \(a\) (1/m). Vectorised.

scattering

Scattering coefficient \(b\) (1/m). Vectorised.

Value

Beam attenuation coefficient \(c\) (1/m).

References

Johnsen S (2012) The Optics of Life. Princeton University Press, ch. 5.

See also

single_scattering_albedo, transmittance, visual_range

Examples

beam_attenuation(absorption = 0.1, scattering = 0.05)   # 0.15
#> [1] 0.15