GNSS has become one of the most widespread measurement technologies, allowing the achievement of cm-level positioning accuracy, especially with the use of differential techniques. The solution accuracy is heavily dependent on the number and geometric distribution of the visible satellites. This makes GNSS quite ineffective in dense city areas where there is a limited view of the sky. Research at the University of Nottingham [1] also outlined problems with using GNSS systems in the North-South orientated monitoring work in the Europe.