Why is GPS Ineffective Inside Buildings? GPS Alternatives for Positioning and Tracking
Source - Nikita_Krushko
The global positioning system (GPS) is widely used all over the world for navigation, tracking, and defining object location. Its operating principle is based on measuring the arrival time of the synchronized signal coming from satellites to antennas (receivers). The technology allows pinpoint the location outside the building with an accuracy of up to 5-10 m. However, in the case of indoor GPS tracking, the system loses its precision. That is due to the inability of signals to penetrate the structure of a building. To enable precise indoor positioning and navigation one should make use of GPS alternatives developed specifically for indoor environments.
Drawbacks of using GPS for Indoor Positioning
Positioning systems are actively used in healthcare, logistics, manufacturing.
In the case of indoor GPS, the average error is 6 meters. Under some conditions, it may not reach receivers or come with distortions and delays. Even advanced antennas can’t deliver the exact location inside buildings, tunnels, basements. Since the indoor GPS system works within an ultra-high radio frequency range, the quality of signals can be negatively affected by the following factors:
- thick walls;
- magnetic storms (rare);
- the low inclination of GPS orbits (for subpolar regions).
While using global positioning inside buildings, GPS signals are blocked or reflected by the walls of the building, thus becoming not powerful enough for localization. To ensure proper signal reception, receivers have to be installed near windows, which isn't always possible or convenient.
Alternative Technologies for Indoor Navigation and Tracking
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Stable and accurate indoor navigation and positioning can be achieved by using technologies similar to GPS. BLE, Wi-Fi, and UWB are the most effective ones. Let’s compare them in detail: GPS vs WiFi and Bluetooth vs GPS.
One of the most convenient tools for tracking objects indoors is the Bluetooth Low Energy technology. To set up indoor positioning BLE beacons should be installed inside the facility. The beacons then will emit BLE signals at a predefined frequency.
Advantages of the technology:
- low energy consumption;
- possibility to localize an object with an accuracy of up to several meters;
- simple deployment and minimal maintenance.
Autonomy and insignificant size the BLE technology is supported by most modern smartphones. It is the most economical one among similar systems on the market and provides high accuracy localization inside buildings.
GPS vs Wi-Fi
Wi-Fi technology is sometimes used as an alternative to GPS for indoor positioning. The reason for its popularity is its widespread occurrence. Access points can be found in any building, which allows leveraging of existing infrastructure.
The active range of access points is up to 150 m and positioning is carried out using smartphones.
Main advantages of the system:
- application based on the existing infrastructure;
- long-range of signal (up to 150 m);
- scalability without manual intervention;
- compatibility with other technologies for indoor navigation.
The UWB technology has a great potential for indoor positioning. It is the most accurate among the existing systems. Achievable accuracy is up to 20 cm. Calculations are performed with the help of ultra-wideband signals that are sent at a frequency of up to several GHz. The reception of these signals doesn’t require direct visibility and can be performed by a limited number of components.
Advantages of the platform:
- resistance to noises;
- spectral flexibility;
- simultaneous support of hundreds of channels;
- highly accurate object tracking.
Navigine is ready to help you to choose an indoor positioning system to solve any task of positioning or tracking indoors. We provide our customers with effective tools that are fully consistent with the market needs.