In this data article, analysis of surface refractivity and water vapour density in Southeast, Nigeria were reported. The meteorological data were collected for the period of 39 years between 1973 and 2012 from National Oceanic and Atmospheric Administration (NOAA) Climatology Centre. Five locations considered in the study area includes: Enugu, Onitsha, Abakaliki, Aba and Ihiala. Descriptive sta...

Radio occultation events recorded on 28–29 July 2004 by the " BlackJack " GPS receiver aboard the GRACE-B satellite are analyzed. The high stability of the receiver clock allows for the implementation of a zero difference technique rendering clock calibrations with concurrent observations of a reference GPS satellite unnecessary. Thereby the usage of ionospheric correction procedures for the de...

The Climate Absolute Radiance and Refractivity Observatory will be a climate benchmarking mission intended to include instruments for measuring Earth’s atmospheric refractivity by GNSS radio occultation (RO), high spectral resolution thermal infrared spectra emitted from the Earth, and the spectrally resolved reflected shortwave spectrum. Climate benchmarking is necessary to establish a record ...

In this study different approaches based on multilayer perceptron neural networks are proposed and evaluated with the aim to retrieve tropospheric profiles by using GPS radio occultation data. We employed a data set of 445 occultations covering the land surface within the Tropics, split into desert and vegetation zone. The neural networks were trained with refractivity profiles as input compute...

In this paper, clear-air fade depth and outage probability occurrence of microwave signals is estimated based on the effect of tropical geoclimatic factor derived from atmospheric refractivity gradient computed for three years (January 2011-December 2013) of measurement of air temperature, pressure and relative humidity for terrestrial line of sight (LOS) link design application in Akure, Niger...

Large-eddy simulation (LES) has been successfully used by the atmospheric community to generate fine resolution fields of turbulent refractivity. These fields can be directly used for the wave propagation problem in the megahertz range but not for the waves of higher frequencies. Numerical computation of these high frequency waves require very fine grid resolution, which is beyond the capabilit...

In this paper, a method for estimating atmospheric refractivity from sea and land clutters is proposed. To estimate the refractivity, clutter power spectrums based on an artificial tri-linear model are calculated using Advanced Refractive Prediction System (AREPS) simulator. Then, again obtained measured data AREPS actual operation, spectrum reflectivity can be replaced with real-time collected...

PURPOSE The recently defined molar-refractivity-partition index was applied to a family of 1,3,5- thiadiazin-2-thione derivatives in order to establish quantitative structure-antitumoral models. The goal of this effort is to establish the relationships between the structure and biological response of these compounds. METHOD After the splitting of the sample in two sets, their indices were cor...