https://obs-web.rs.umbc.edu/ 2026-09-09T18:32:08+00:00 https://obs-web.rs.umbc.edu/ https://obs-web.rs.umbc.edu/lib/tpl/bootstrap3/images/favicon.ico text/html 2023-11-14T13:11:58+00:00 Anonymous (anonymous@undisclosed.example.com) https://obs-web.rs.umbc.edu/doku.php?id=wiki:astronomy:observational_astronomy:observational_astronomy:extinction&rev=1699985518&do=diff Atmospheric Extinction Atmospheric extinction is the term used to describe any removal of radiance from incidence. This removal can be due to scattering events that scatter radiance out of incidence or due to absorption events that directly remove the radiance via transformations of the radiant energy to another form.$$dI_\lambda = 0$$$$dI_\lambda \propto - I_\lambda \sec{z} dx$$$\alpha_\lambda(x)$$$dI_\lambda = - \alpha_\lambda(x)I_\lambda \sec{z} dx$$$$\int_b^t \frac{dI_\lambda}{I_\lambda} = …