A Framework for Graphical GNSS Multipath and NLOS Mitigation

Positioning in urban areas is still a challenge due to non-line-of-sight (NLOS) and multipath reception. This paper explores the geometrical characteristics of the GNSS ranging measurement by a graphical representation to better indicate the pseudorange consistency, which can be used to mitigate the NLOS and multipath receptions. The graphical representation is created by the grid-based method combined with the single differenced technique, which is called the single differenced residual map (SDRes Map). With the graphical properties of the SDRes Map, four main focuses of the NLOS/multipath problems, including positioning, signal status prediction, satellite weighting calculation, and NLOS/multipath error calculation, are able to be tackled simultaneously and demonstrated to have superior performance against the conventional or even state-of-the-art method methods.