A New Approach to Investigation of the Relationship of VLF Signals by Using Longitudinal Analysis Models

E Guzel,M Canyılmaz,M Yaşar,M B Kılıç

doi:10.1155/2013/861682

Abstract

Longitudinal analysis models are applied to analyze very low frequency (VLF) electromagnetic waves signals. They are useful in realization of nuance of relationship between parameters of concern which change over time. VLF data are so important for the communication and determining the disturbances in the lower ionosphere. In this study, we used a four-day VLF signal data which come from transmitter stations located at two different countries to Elazığ receiver system. A very important feature of this data is that there is a strong relationship between days and signals. At first, the exploratory data analysis was applied for identification of data. Then, marginal, random-effects, and transitional models were used to analyze the data, respectively. The marginal model is found more appropriate than the other models used for VLF data analyses. As a result of this process, a new method has been added to the analysis of VLF signal data.

Highlights

very low frequency (VLF) radio waves (3–30 kHz) are guided by the spherical waveguide formed between the Earth’s surface and the lower ionosphere and can propagate long distances [1]
Exploratory data analysis was promoted by Hoaglin et al to encourage statisticians visually to examine their datasets, to formulate hypotheses that could be tested on new datasets [8]
This paper presents a comparative study of longitudinal analysis techniques and models applied to experimental VLF signals and investigations of the relationship between two VLF transmitters

Summary

Introduction

VLF radio waves (3–30 kHz) are guided by the spherical waveguide formed between the Earth’s surface and the lower ionosphere and can propagate long distances [1]. The observed properties of VLF signals can be used to determine the spatial and temporal structure of localized disturbances in the lower ionosphere [3]. Statisticians, as well as others who apply statistical methods to data, have often made preliminary examinations of data in order to explore their behavior In this sense, exploratory data analysis has long been a part of statistical practice [7]. The aim of making longitudinal study is to look at the variation of process across time periods [9] From this point of view, marginal modeling allows for inferences about parameters averaged over the whole population. This paper presents a comparative study of longitudinal analysis techniques and models applied to experimental VLF signals and investigations of the relationship between two VLF transmitters.

Experimental Systems

Longitudinal Approach for the Analysis of VLF Signal Data

40 Day 4 40

Result and Discussion