https://doi.org/10.1351/goldbook.14030
Physical process by which the incoming electromagnetic radiation is forced to deviate from a straight trajectory by non-uniformities in the medium.
Notes:
- Physical phenomenon taking into account scattered radiative energy from the rays in the direction \(\mathit{\Omega}\) considered in the radiative transfer equation (RTE) into any direction \(\mathit{\Omega}'\).
- Mathematical definition: \({\rm{Sc}}_{\rm{out}} = \sigma_{\lambda} (\boldsymbol{x},t) L_{\mathit{\Omega},\lambda} (\boldsymbol{x},t)\) where \(\boldsymbol{x}\) is the coordinate in a three-dimensional space in the path of the beam, \(t\) is the time coordinate, \(\sigma_{\lambda} (\boldsymbol{x},t)\) is the space- and time-dependent linear napierian scattering coefficient, \(L_{\mathit{\Omega},\lambda} (\boldsymbol{x},t)\) is the incident space- and time-dependent radiance in the direction \(\mathit{\Omega}\). SI unit is \(\pu{W sr-1 m-4}\). Common unit is \(\pu{W sr-1 cm-3 nm-1}\).
- The mathematical definition in photon terms is: \({\rm{Sc}}_{\rm{out}} = \sigma_{\lambda} (\boldsymbol{x},t) L_{\rm{p},\mathit{\Omega},\lambda} (\boldsymbol{x},t)\) with \(L_{\rm{p},\mathit{\Omega},\lambda} (\boldsymbol{x},t)\) the incident space- and time-dependent photon radiance. SI unit is \(\pu{s-1 sr-1 m-4}\) in photon number basis and \(\pu{mol s-1 sr-1 m-4}\) in chemical amount basis. Common unit in photon number basis is \(\pu{s-1 sr-1 cm-3 nm-1}\) and \(\pu{einstein s-1 sr-1 cm-3 nm-1}\) in chemical amount basis.