Localization Using DVB-T Signals: Experimental Insights and Validation

Accurate positioning, navigation and timing (PNT) is important for military and civilian applications alike. In recent years navigation using signals of opportunity (SOPs) has received increased interest as a complement or alternative to Global Navigation Satellite Systems (GNSS). We previously proposed a localization framework using opportunistic digital television signals. In it, a navigator localizes itself aided by a stationary base station at a known location, using two time difference of arrival (TDOA) measurements and one twoway ranging (TWR) measurement. In this work we implement and evaluate the proposed framework using real measurements, and based on this propose an extended model which includes the difference in clock bias between the navigator and the base station. The experimental results show that the framework can achieve a root mean square error (RMSE) in absolute position of less than 50 m provided that at least three TDOA measurements are used (with or without TWR), and sometimes if only two TDOA measurements are used in combination with a TWR measurement. We also show experimentally that the transmitter clocks are stable enough for the navigator to extract the TDOA measurements relying only on its own current measurements and previously collected data by the base station. Thus, by replacing the TWR measurement with a third TDOA measurement, the base station need not be active or communicate with the navigator during the localization. In scenarios where communication is undesirable or impossible, this can be advantageous.