Patent ID: 8593347

Claim:
A Global Navigation Satellite System (GNSS) receiver comprising: (a) a radio frequency front end for receiving ranging signals from satellites of a GNSS constellation; (b) a navigation processor for calculating a location of the GNSS receiver from said ranging signals; and (c) a repository of data selected from the group consisting of: (i) a digital elevation map, (ii) a tunnel database that includes coordinates of at least one entrance of at least one tunnel, and (iii) a structure database that includes, for each of at least one structure, a respective description of said each structure in sufficient detail to model multipath reception of said ranging signals by said radio frequency front end when the GNSS receiver is within a respective multipath distance of said each structure; wherein said navigation processor is operative to include at least a portion of said data in said calculating of said location of the GNSS receiver.