In the near future, the vehicles offering advanced driver assistance or fully autonomous operation. It will require increasingly accurate position information, available in all driving conditions and with 100 percent availability. In generally, a single sensor cannot meet these requirements alone and so it is necessary to use a combined sensor suite solution incorporating different kinds of sensors working together. As the only source of absolute position, velocity and time, Global Navigation Satellite systems (GNSS) play a critical role in next generation positioning systems. In this paper, we are dealing with modern GNSS solutions and presents the results of the comparison of two high-precision GNSS systems in different driving conditions and presents conclusion for the develop of autonomous localization system.