Method and system for determining position information utilizing a portable electronic device lacking global positioning system (GPS) satellite reception capability

摘要

A portable electronic device that can obtain position information despite lacking GPS reception capability includes data storage that stores a reference position, a plurality of inertial motion sensors, and computational circuitry. The inertial motion sensors detect movement of the portable electronic device and output motion signals to the computation circuitry indicative of the sensed movement. In response to these motion signals and the stored reference position, the computational circuitry computes a position of the portable electronic device.