Modified refractive index

From Glossary of Meteorology



modified refractive index[edit | edit source]

In radio engineering, the refractive index of air on a hypothetical flat earth, given by
ams2001glos-Me14
where z is the height above the surface, R is the earth's radius, and n is the actual refractive index of air.

For a spherical earth with an atmosphere having a uniform refractive index, rays are curved relative to the earth. This is approximately equivalent to a flat earth with an atmosphere in which the refractive index varies with height as z/R.
See modified refractivity.


Copyright 2024 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.