Results 261 to 270 of about 1,255 (307)

A Simple Radio Refractivity Computer

IETE Journal of Research, 1966
ABSTRACTA simple electrical circuit analogue designed for use in rapid calculation of atmospheric refractive indices from the Radio Sonde data is described. The circuit yields the dry and wet terms of refractivity separately within ±1N units of accuracy.
openaire   +1 more source

Predicting radio refractivity using a stochastic model

2014 XXXIth URSI General Assembly and Scientific Symposium (URSI GASS), 2014
The radio refractivity of the atmosphere is a very important variable in radio communication. This paper attempts to model the radio refractivity over a tropical station (Akure, Southwestern Nigeria) with the aim of predicting future values. Atmospheric variables (temperature, pressure and relative humidity) were obtained over a period of eighteen ...
Samuel T. Ogunjo, Moses O. Ajewole, A. T. Adediji, J. S. Ojo   +3 more
openaire   +1 more source

Refractive scintillation of extragalactic radio sources

AIP Conference Proceedings, 1988
Compact extragalactic sources can display intensity fluctuations which are caused by fluctuations in the electron density of the interstellar medium. The 1/e time scale of these ‘‘refractive scintillations’’ can be many years. The intensity structure function D1(τ)=
openaire   +1 more source

Modeling Surface Radio Refractivity in Ulaanbaatar, Mongolia

2018 USNC-URSI Radio Science Meeting (Joint with AP-S Symposium), 2018
This paper presents a hybrid model for surface radio refractivity. This model is a combination of deterministic and probabilistic models. The deterministic model represents regular changes in refractivity and the probabilistic model indicates random variations in the regular behavior.
Jamiyan Sukhbaatar, Nyamjav Jambaljav
openaire   +1 more source

Models of the Atmospheric Radio Refractive Index

Proceedings of the IRE, 1959
Evaluation of atmospheric refraction effects on UHFVHF radio propagation has long been accomplished with the convenient four-thirds earth concept of Schelling, Burrows, and Ferrell. This method has proven particularly useful in evaluating performance of point-to-point radio communications systems.
B. Bean, G. Thayer
openaire   +1 more source

A Nomogram for Atmospheric Radio Refraction

Radio Science, 1967
A six‐stage nomogram is presented for determining the refraction of a radio wave entering the earth's atmosphere in terms of surface meteorological conditions and the apparent elevation angle of the incoming wave.
openaire   +1 more source

Refractive Indexes of Gases at High Radio Frequencies

Nature, 1941
SINCE atmospheric refraction plays an important part in the bending of ultra–short radio waves round the surface of the earth, an adequate study of the propagation of these waves requires a knowledge of the refractive indexes of gases at very high frequencies.
openaire   +1 more source

Ionospheric refraction in radio source observations at long radio wavelengths

Journal of Astrophysics and Astronomy, 1984
Ionospheric refraction effects encountered in radio source observations in the 30 to 75 MHz range with the Clark Lake TPT telescope are discussed. It is found that simple calibration procedures are sufficient to provide positions of unknown sources with an accuracy of approximately one arcmin.
openaire   +1 more source

The Radio Refractive Index of Air

Proceedings of the IRE, 1962
This is a tutorial paper. The derivation of the classical Debye expression for the radio refractive index is reviewed. Recent determinations of the constants in this expression are reviewed and the conclusion reached that differences between constants are small compared with the error in using standard meteorological data in the formula.
openaire   +1 more source

Sensing of radio refractivity and aerosol extinction

Proceedings of IGARSS '94 - 1994 IEEE International Geoscience and Remote Sensing Symposium, 2002
Sensing of radio refractivity has historically been accomplished with direct sensing techniques such as radiosondes. While direct sensing techniques provide good data for propagation assessment purposes, remotely sensed data would be more desirable. Various direct and remote sensing techniques and an assessment of their potential operational usefulness
openaire   +1 more source