Indoor positioning system

An indoor positioning system (IPS) is a network of devices used to locate people or objects where <a href="/facts/Global_Positioning_System/DKVLnzF3">GPS</a> and other satellite technologies lack precision or fail entirely, such as inside multistory buildings, airports, alleys, parking garages, and underground locations.
A large variety of techniques and devices are used to provide indoor positioning ranging from reconfigured devices already deployed such as smartphones, <a href="/facts/Wi-Fi/u94quCsx">WiFi</a> and <a href="/facts/Bluetooth/sWAjpMrj">Bluetooth</a> antennas, digital cameras, and clocks; to purpose built installations with relays and beacons strategically placed throughout a defined space. Lights, radio waves, magnetic fields, acoustic signals, and behavioral analytics are all used in IPS networks. IPS can achieve position accuracy of 2 cm, which is on par with <a href="/facts/Real-time_kinematic/MrlAvKU4">RTK</a> enabled GNSS receivers that can achieve 2 cm accuracy outdoors.
IPS use different technologies, including distance measurement to nearby anchor nodes (nodes with known fixed positions, e.g. <a href="/facts/WiFi/u94quCsx">WiFi</a> / <a href="/facts/LiFi/yopv7qBA">LiFi</a> <a href="/facts/Wireless_access_point/701JjIzt">access points</a>, <a href="/facts/Bluetooth_low_energy_beacon/KXNK97xS">Bluetooth beacons</a> or Ultra-Wideband beacons), <a href="/facts/Magnetic_positioning/Ngme32PY">magnetic positioning</a>, <a href="/facts/Dead_reckoning/sljJ7nCT">dead reckoning</a>. They either actively locate mobile devices and tags or provide ambient location or environmental context for devices to get sensed.
The localized nature of an IPS has resulted in design fragmentation, with systems making use of various <a href="/facts/Optical/p0vq4S1T">optical</a>, <a href="/facts/Radio/XFr909M2">radio</a>, or even <a href="/facts/Acoustics/2GpQUymy">acoustic</a>
technologies.
IPS has broad applications in commercial, military, retail, and inventory tracking industries. There are several commercial systems on the market, but no standards for an IPS system. Instead each installation is tailored to spatial dimensions, building materials, accuracy needs, and budget constraints.
For smoothing to compensate for <a href="/facts/Stochastic/uMbgL94r">stochastic</a> (unpredictable) errors there must be a sound method for reducing the error budget significantly. The system might include information from other systems to cope for physical ambiguity and to enable error compensation.
Detecting the device's orientation (often referred to as the compass direction in order to disambiguate it from smartphone vertical orientation) can be achieved either by detecting landmarks inside images taken in real time, or by using trilateration with beacons. There also exist technologies for detecting magnetometric information inside buildings or locations with steel structures or in iron ore mines.

Indoor positioning system open-in-new

Indoor positioning system