Time Difference of Arrival (TDOA) sensor
ime difference of arrival (TDOA) is commonly used in civil and military surveillance applications to accurately locate an aircraft, vehicle or stationary emitter by measuring the time difference of arrival (TDOA) of a signal from the emitter at three or more receiver sites. It locates an object by accurately computing the time difference of arrival (TDOA) of a signal emitted from the object to three or more receivers. It also refers to the case of locating a receiver by measuring the TDOA of a signal transmitted from three or more synchronized transmitters.
IAI has developed a unique a Time Difference of Arrival (TDOA) infrastructure, which will provide the performance needed for law enforcement applications. This surveillance technology allows for locating any wireless communication device inside or outside of buildings. It can be used for both cooperative tracking (e.g. firefighter/police/EMS radios/warfighter) without requiring an additional transmitter, and non-cooperative tracking (e.g. enemy’s radio, hijacker’s cell phone, or smuggled cell phone inside a prison). The system employs Ultra Wideband (UWB) enhanced TDOA technique. The TDOA enhanced sensor will not only detect signals of interest but also locate the positions of the emitting devices (cell/cordless phones, walkie-talkies, etc.) in 2D or 3D. At the heart of our approach is the ability of UWB transceivers (radios) to wirelessly synchronize multiple RF receivers. The same UWB link that is used for time synchronization can also carry data for two-way communication, and provide fast, accurate ranging in both Line of Sight (LOS), and non-LOS environments. These three capabilities: ranging, synchronization, and communications are the three necessary functions needed to localize transmitters by TDOA methods.
IAI is also researching narrowband synchronization and ranging techniques. This would replace the short range UWB communication link with a longer range VHF-UHF communication radio link, and enable the monitoring of larger areas of interest.