Statistical behaviour of refractivity gradient in the tropics

Author

Dhein, N.R. ; Pontes, M.S. ; da Silva Mello, L.A.R.

Author_Institution

Catholic Univ. of Rio de Janeiro, Brazil

fYear

1993

fDate

1993

Firstpage

340

Abstract

The knowledge of the spatial behaviour of the refractivity in the lower troposphere is an essential information for the design of UHF and SHF radio links, as well as for the evaluation of interference between terrestrial communication systems. The paper presents results of refractivity measurements at 16 sites in several climatic regions in Brazil. An experiment underway in seven additional links, aiming to estimate the effective K factor of the Earth from attenuation measurements in diffracted links is also described. Depending on the site, different measurement methods were employed: radio sonde measurements or direct measurements using refractometers. The probability distributions obtained from measured data indicate that, in tropical regions, the media values of refractivity gradient are usually significantly higher than those found in temperate climates

Keywords

atmospheric electromagnetic wave propagation; attenuation measurement; electromagnetic wave diffraction; probability; radio links; radiowave propagation; Brazil; Earth; SHF; UHF; attenuation measurements; climatic regions; diffracted links; direct measurements; effective K factor; interference; lower troposphere; measured data; measurement methods; probability distributions; radio links; radio sonde measurements; refractivity gradient; refractivity measurements; refractometers; spatial behaviour; statistical behaviour; terrestrial communication systems; tropical regions; tropics;

fLanguage

English

Publisher

iet

Conference_Titel

Antennas and Propagation, 1993., Eighth International Conference on

Conference_Location

Edinburgh

Print_ISBN

0-85296-572-9

Type

conf

Filename

224705