Accuracy increase of determining navigation parameters for long-range radionavigation systems

In the given article the problem of increasing the objects coordinates’ determination accuracy from ground-based long-range radio navigation systems (RNS) was considered. The examples of such systems are the system of global coverage “Omega”, operating in VLF-band, the system of LF-band “Loran-C”, as well as MF-band systems “Sprut”, “Bras”, and others. As these systems operate in a low-frequency part of the radio spectrum, the results of measurements of the navigation parameters (differences of ranges, quasi-ranges, etc.) are influenced by characteristics of the underlying surface, resulting that the measured values of these parameters may vary significantly from their true values. The characteristics of the underlying surface include such parameters as resistivity and dielectric permittivity. If it is possible to provide a precise definition of the values of the characteristics of the underlying surface, it will be possible to calculate corrections to the measured values of the navigation parameters using known methods. Further, the measured values of the navigation parameters can be adjusted, which will increase the overall accuracy of determining the object’s coordinates. To determine the conductivity and the dielectric permittivity electromagnetic methods (EMM) equipment to determine the parameters of the underlying surface can be used. This equipment was developed in Krasnoyarsk Department of Geophysics OJSC “Almazzolotoavtomatika” with the participation of the Department of radio Electronic systems, of Siberian Federal University. The main purpose of this equipment is mineral exploration. The equipment provides measurements in the frequency band, corresponding to the operating band of the investigated radio-navigation systems. It allows to measure parameters of the underlying surface on the RNS operating frequencies values, and contributes to a more precise determination of the underlying surface parameters. In the article the mathematical expressions relating the parameters of the underlying surface with the measured values of the components of the field were presented, as well as a monogram, which can determine the values of conductivity and dielectric permittivity from measurements, made of the device. The description of the working program that performs the calculation of the parameters of the underlying surface, designed to run on a personal computer in the operating system environment Microsoft Windows XP/7/8 was given. The developed program provides automated input of measurement data from the measuring unit and the calculation of the underlying surface parameters values. The calculated results are output to a file, which can later be read and processed using Microsoft Office Excel program. At the end of the article the conclusion about the possibility of using the developed tool to determine the parameters of the underlying surface, required to improve the accuracy of coordinates determination using long-range RNS, operating in low-frequency part of the radio spectrum is given. The other possible applications of the device described as in communication technology, and for its intended purpose - in the electric prospecting are shown.