Ultra Wide Band Time Difference Of Arrival Sensor

We propose to develop an unattended system which records portions of the VHF and UHF spectrum, determine positions of the responsible transmitters, and report raw IF waveforms and transmitter locations to a user by means of a LPI/LPD data link. We will use ultra wideband (UWB) transceivers (radios) to wirelessly synchronize multiple RF receivers. UWB spreads its energy over several Giga Hertz so it is highly LPI/LPD. This method does not rely on GPS so the synchronization will be maintained when the GPS signal is not available. A time resolution better than 1 nanosecond is achievable using existing UWB chipsets. The same link that is used for time synchronization can carry data for two-way communication, and provide fast, accurate ranging in Line of Sight (LOS), and non-LOS environments. These three capabilities are necessary functions needed to localize transmitters by Time Difference of Arrival (TDOA) methods. TM-UWB radar or radio generates narrow pulse (0.5 ns) pseudo-randomly in time. In order to receive these pulses coherently, the receiver needs to synchronize with the transmitter down to tens of picoseconds. We plan to take advantage of this precision timing to achieve time synchronization among multiple RF sensors making up the TDOA sensor.