Reflectance

Reflectivity is the limit value of reflectance as the sample becomes thick; it is the intrinsic reflectance of the surface, hence irrespective of other parameters such as the reflectance of the rear surface.

Albedo can then be given as: : Directional-hemispherical reflectance is sometimes referred to as black-sky albedo and bi-hemispherical reflectance as white-sky albedo.

The individual reflectance or transmittance of the domains is averaged if the macroscopic reflectance or transmittance is to be calculated.

Shan Kothari et al, Predicting leaf traits across functional groups using reflectance spectroscopy, DOI: 10.1111/nph.

To make this discovery, Li, Paul Lucey and others analysed the hyperspectral reflectance data acquired by the Moon Mineralogy Mapper (M3) designed by NASA JPL onboard India's Chandrayaan-1 mission.

Although such reflectance properties are different from those of any terrestrial terrains, they are typical of the regolith surfaces of airless Solar System bodies.

And let P be the Planar Albedo, which represents the total reflectance from the scene.

Another derivation of the formula, based on a physical reflectance transmittance model, can be found in a 1981 paper by Bruce A. Wallace. citation A third approach is found by starting out with two very simple assumptions.

Assuring luminaire setback is greater than 90° from highly reflective surfaces also diminishes reflectance.

Communications Modulated retroreflectors, in which the reflectance is changed over time by some means, are the subject of research and development for free-space optical communications networks.

Hand-held OTDRs are commonly used to measure fiber links and locate fiber breaks, points of high loss, high reflectance, end-to-end loss, and Optical Return Loss (ORL).

Here satellites use different sensor packages to passively measure the reflectance from parts of the electromagnetic spectrum or radio waves that were sent out from an active sensor such as radar.

In practice, a bidirectional reflectance distribution function (BRDF) may be required to accurately characterize the scattering properties of a surface, but albedo is very useful as a first approximation.

In remote sensing applications, anisotropy functions can be derived for specific scenes, immensely simplifying the calculation of the net reflectance or (thereby) the net irradiance of a scene.

Male jumping spiders have visual patches of UV reflectance, which are ornamentations used to attract females.

Nano-porous materials can achieve refractive indices nearly that of vacuum, in one case obtaining average reflectance of 0.045%.

Process yellow is based on a colorant that reflects the preponderance of red and green light, and absorbs most blue light, as in the reflectance spectra shown in the figure on the lower right.

The combined reflectance for this case is 2R/(1 + R ), when interference can be neglected (see below).

The most important properties are the surface reflectance ( albedo ), the ability to transfer heat (thermal diffusivity), and the ability to change state ( latent heat ).

The product of the source spectrum and the reflectance spectrum of the pigment results in the final spectrum, and the appearance of blue.