Global Positioning System 505 Global system for mobile communications 71 Global positioning system 63 Artificial satellites in navigation 43 GPS receivers 37 Automatic tracking 34 Wireless communication systems 34 Inertial navigation 33 Geographic information systems 29 Mobile communication systems 25 Technological innovations 24 Monitoring systems 20 Arduino (Programmable controller) 17 Design and construction 17 Mobile computing 17 Artificial satellites in surveying 16 Inertial navigation systems 15 Radio 15 Data processing 13 Ionosphere 13 Ionospheric electron density 13 Kalman filtering 13 Mobile geographic information systems 13 Remote sensing 13 Global Positioning Systems 12 Wireless LANs 12 Automobiles 11 Electron data processing 11 Security systems 11 Earthquakes 10