Theoretical Limits of SoOP TDOA Localization of Unmanned Systems with Imperfect Synchronization

Self-localization is of crucial importance to Unmanned Aerial Vehicle (UAV) industry. Localization systems such as the Global Positioning System (GPS) are prone to jamming and spoofing. Localization using the Signal-Of-Opportunity (SoOP) gained much attention recently as an alternative to typical localization systems. We consider a general scenario where a receiver deployed on a mobile UAV finds its location based on Time Difference Of Arrival (TDOA) measurements with a number of unsynchronized reference Base Station (BS) receivers using signals from unsynchronized transmitters. The UAV has relative time offsets and clock skews with the BSs. We derive the Cramer-Rao Lower Bound (CRLB) of the UAV location and relative skews. Then, we plot them for Phase Alternating Line (PAL) analog TV transmission as SoOP.