Geographic Location Systems
A Geographic Location System (GLS) is a technology that uses various methods to determine the location of a device or object on the earth's surface.
The most widely used GLS technology is the Global Positioning System (GPS), which uses signals from a network of satellites to provide location and time information to users on the ground. technologies include:
- GPS (Global Positioning System): A satellite-based navigation system that provides location and time information to users on the ground.
- DGPS (Differential GPS): A system that improves the accuracy of GPS signals by using ground-based reference stations to correct for errors in the satellite signals.
- RTK (Real-Time Kinematic) GPS: A high-precision GPS system that uses a separate radio link to provide real-time corrections and sub-centimeter accuracy.
- PPK (Post-Processed Kinematic) GPS: A method of improving the accuracy of GPS data by using data from multiple receivers and processing it after the data has been collected.
- LIDAR-based positioning: A technology that uses laser scanning and ranging to determine the position of a device.
- A-GPS (Assisted GPS): A system that uses a combination of GPS and other location technologies, such as cell tower triangulation or Wi-Fi positioning, to improve the accuracy and availability of GPS signals.
- SBAS (Satellite-Based Augmentation Systems): A system that uses additional satellites and ground-based reference stations to improve the accuracy and integrity of GPS signals. Examples include WAAS (Wide Area Augmentation System) and EGNOS (European Geostationary Navigation Overlay Service)
- PPP (Precise Point Positioning): A technique that uses GPS measurements and precise orbit and clock information to determine positions with centimeter-level accuracy.
Because these systems depend on satalite signals they do not work well indores. There are several geographic location systems that do not depend on Global Positioning System satellites and can therefor be used inside or outside including:
- Bluetooth Low Energy (BLE) Beacon-based systems: These systems use small, low-power devices called beacons that emit a Bluetooth signal that can be detected by smartphones or other devices. The signal can be used to determine the location of the device within a building or other indoor space.
- Wi-Fi-based systems: These systems use the signal strength of Wi-Fi networks to determine the location of a device. The device's location is determined by measuring the signal strength of nearby Wi-Fi networks and comparing it to a map of known Wi-Fi network locations.
- Ultra Wideband (UWB) : A wireless technology that uses a wide range of frequencies to transmit data over short distances.
- Ultrasound-based systems: These systems use high-frequency sound waves to determine the location of a device. The device sends out an ultrasound signal, which is then received by a network of receivers. The time it takes for the signal to travel to each receiver is used to calculate the device's location.
- Inertial Navigation System: These systems use accelerometers and gyroscopes to determine position and orientation based on the movement of the device.
- Visual-based systems: These systems use cameras and computer vision algorithms to determine the location of a device. The device's location is determined by comparing images of the device's surroundings to a map of known locations in the environment.
- Magnetic-based systems: These systems use the earth's magnetic field to determine the location of a device. The device's location is determined by measuring the strength and direction of the magnetic field at the device's location.
- Smartphone-based systems: These systems use the sensors on smartphones, such as the accelerometer, GPS, and compass, to determine the location of the device.
Each of these systems has its own advantages and disadvantages. The best system for a particular application will depend on factors such as the size of the indoor space, the number of users, and the required accuracy.