Published

2026-01-21

Calculating the Changes in the User Terminal Figure of Merit (G/T) as a Function of Link Conditions: A Review

Cálculo de los cambios en la figura de mérito de las estaciones de usuario (G/T) en función de las condiciones del enlace: una revisión

Keywords:

satellite communications, Earth stations, figure of merit, antenna temperature, sky brightness, system noise temperature (en)
comunicaciones satelitales, estación terrena, figura de mérito , temperatura de ruido de antena, temperatura de ruido (es)

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Activities such as the design and optimization of satellite constellations for telecommunications, communication solutions engineering, or GEO/non-GEO satellite inter-system coexistence applications benefit from methods to compute changes in Earth station equivalent noise temperature, a product of the dynamic nature of link geometry and the propagation channel. This paper addresses said requirement. Starting with a review of the user terminal G/T and Earth station noise temperature, methods are developed to compute the change in noise temperature introduced by varying elevation angle and propagation channel conditions. These methods are useful for engineering analyses when the noise contributions from each component of the Earth station receive chain are not known, especially considering the increased impact of clouds and gasses on GEO and non-GEO links operating in frequencies of the Q, E, and W bands. Examples of use and benefits are provided, as well as considerations on the applicability and validity of the methods.

Actividades como el diseño y la optimización de constelaciones de satélites para telecomunicaciones, la ingeniería de soluciones de comunicación o las aplicaciones de coexistencia intersistémica entre satélites GEO y no GEO se benefician de métodos para calcular los cambios en la temperatura equivalente de ruido de la estación terrena, un producto de la naturaleza dinámica de la geometría del enlace y del canal de propagación. Este artículo aborda dicho requerimiento. A partir de una revisión de la G/T del terminal de usuario y de la temperatura de ruido de la estación terrena, se desarrollan métodos para calcular el cambio en la temperatura de ruido introducido por la variación del ángulo de elevación y de las condiciones del canal de propagación. Estos métodos son útiles para los análisis de ingeniería cuando no se conocen las contribuciones de ruido de cada componente de la cadena de recepción de la estación terrena, especialmente considerando el mayor impacto de las nubes y los gases en enlaces GEO y no GEO que operan en las bandas Q, E y W. Se presentan ejemplos de uso y beneficios, así como consideraciones sobre la aplicabilidad y validez de los métodos.

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