Archive for May 4th, 2014

May 4, 2014

Indoor Positioning System



An indoor positioning system (IPS, or micromapping) is a network of devices that wirelessly locate objects or people inside a building. Instead of using satellites like GPS, it relies on nearby anchors (nodes with a known position), which either actively locate tags or provide ambient location or environmental context for devices. Systems use optical, radio, or even acoustic technologies. Integration of data from several navigation systems with different physical principles can increase the accuracy and robustness of the overall solution.

Wireless transmission indoors faces several obstacles including signal attenuation caused by construction materials, multiple reflections at surfaces causing transmission errors, and interference with devices that emit or receive electromagnetic waves (e.g. microwave ovens, cellular phones). Error correction systems that don’t rely on wireless signals are being used to compensate for these shortcomings, such as Inertial Measurement Units (reports velocity, orientation, and gravitational forces using accelerometers and gyroscopes), and Simultaneous Localization and Mapping (SLAM, a technique used by robots and autonomous vehicles to build up a map within an unknown environment).