Reflexância

Reflexância is a term used in various scientific fields, particularly in optics and remote sensing, to describe the property of a surface to reflect incident radiation. It is a measure of how much light or other electromagnetic radiation is reflected by a material compared to how much is incident upon it. The value of reflexância is typically expressed as a ratio or a percentage. It is influenced by several factors including the material's composition, surface texture, and the wavelength of the incident radiation.

In the context of optics, reflexância quantifies the reflectivity of a surface for visible light. For example, a mirror has high reflexância, reflecting almost all incident light, while a black surface has low reflexância, absorbing most of the light. In remote sensing, reflexância is crucial for analyzing Earth's surface from satellite or aerial imagery. Different land cover types, such as vegetation, water, and soil, have distinct reflexância signatures across different wavelengths, allowing scientists to identify and map them.

The spectral reflexância refers to how reflexância varies with the wavelength of the electromagnetic spectrum. This spectral signature is unique to different materials and is used in spectroscopy and remote sensing for identification and characterization. Understanding reflexância is fundamental for applications ranging from designing optical instruments to interpreting environmental data.