Local terrain feature location data is obtained from a local sensor device at a user location without a prior-known global position. The local terrain feature location data characterizes relative distances and directions to a plurality of local terrain features nearest to the user location. Global terrain feature location data stored in at least one hardware memory device is accessed. The global terrain feature location data characterizes relative distances and directions between a plurality of distinctive terrain features located in a defined terrain region in terms of absolute global location coordinates. The local terrain feature location data is compared to the global terrain feature location data to develop multiple pattern matching hypotheses, wherein each pattern matching hypothesis characterizes a likelihood of a subset of the local terrain features matching a subset the global terrain features. Global location coordinates for the user location is then determined from the pattern matching hypotheses.