A system for crowd-sourced fingerprinting has a positioning database and a mobile wireless device. The positioning database is configured to store information relating wireless local area network access point (AP) signal measurements to points of a geographic positioning grid. The mobile wireless device has a satellite positioning system, a transceiver, a motion measurement system, and position estimation logic. The position estimation logic is configured to determine a reference location as the device passes between areas of satellite positioning signal reception and satellite positioning signal non-reception. The device further configured to record measurements of movements provided by the motion measurement system and measurements of signals provided by the transceiver within areas of non-reception and to provide results to the positioning database.