Reliable Urban Canyon Navigation Solution in GPS and GLONASS Integrated Receiver Using Improved Fuzzy Weighted Least-Square Method

Global Positioning System encounters many problems in urban canyons and hard environments because of obstacles that decrease the number of visible satellites in receiver view. So, integration with other satellite-based navigation systems such as Russian Global Navigation Satellite System is utilized in new receivers. Least square as the popular and usual method typically used for navigation solution associates all satellite information with the same weights. However, the satellite impacts in reliability and accuracy of the receiver outputs are different in real condition and can be weighted by intelligent factors. In this paper, an improved fuzzy-weighted least square method is proposed which weights the satellite based on the satellite effect on dilution of precision, elevation angle and a defined constellation factor. Experimental results show that the proposed method can calculate 2D position more reliable and accurate than other popular weighted least square methods. This improvement is more than 57.23 % in a defined figure of merit.