GNSS multipath mitigation techniques in urban scenarios

The global navigation satellite system is advantageous for its significant level of accuracy positioning, timing, and tracking efficiencies. Because of the multipath effect, receiver accuracy is limited in dense cities. Multipath is a mechanism where the transmitted satellite signal is reflected by objects in the range of a receiver, resulting in a mixed-signal that includes the LOS signal and more than one reflected or diffracted signal entering the receiver. In urban and maritime environments, the multipath effect in positioning can be up to 15 to 20 meters. Mitigation methods limit positioning error because of multipath effects while, detection methods only identify the signals which are affected due to multipath, that are to be eliminated from the position solution. The performance of different multipath mitigation methods is examined in this article and techniques that are effective in mitigating multipath errors have been analyzed.