Abstract

SANDIANES GALVEZ, José Rafael. Alternative for calculation of reduced heights over a spherical earth. EAC [online]. 2021, vol.42, n.1, pp. 21-33.  Epub May 17, 2021. ISSN 1815-5928.

During determination of coverage zones of radio mobile services, transmitters of television and others emitters of ultra-short-waves and, also, when is realized the analysis of radio relay lines or radar range, is necessary to predict the intensity E of electric field taking on account Earth´s sphericity. This prediction is realized, in illuminated region or zone, using earth´s plane expressions, but taking reduced heights instead of real heights. Reduced heights (RH) diminish when distance R grows, but is more notable the affectations when we are near the limit of maximum direct visibility distance: Ro. The limit distance Ro is an important magnitude during determination of coverage in cited radio services. In this article are summarized expressions present in references but the main objective is propose another derivate expressions that depends of relatives distances ( and relation m of antennas heights. With this proposition is wished to facilitate the analysis and calculation of RH, but with normalized dependences, avoiding unnecessary recurrences and with reduced processing time of computing calculations.

Keywords : reduced heights; range of direct visibility; illuminated zones; coverage zones.

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