Source Localization Based on FDOA and TDOA With Bounded Sensor Location Errors and Changing Carrier Frequency

This study tackles locating a noncooperative source based on passive measurements of multiple sonar sensors, such that every sonar sensor can measure both frequency difference of arrival (FDOA) and time difference of arrival (TDOA) of the source’s sound signal. This article considers a scenario where the unknown carrier frequency of the source may vary as time elapses. Furthermore, there can be large errors in underwater sensor localization, since global positioning system (GPS) cannot be used in underwater environments. This study addresses FDOA-TDOA localization under the assumption that a sensor’s location error is bounded above and that the speed limit of the source is accessible a priori. As far as we know, this manuscript is novel in solving FDOA-TDOA localization, considering scenarios where a sensor’s location error exists and unknown carrier frequency can vary as time elapses. In addition, our research is novel in not requiring a prior information on the FDOA-TDOA measurement noise power. The effectiveness of the proposed hybrid FDOA-TDOA localization scheme is demonstrated by comparing it with the state-of-the-art hybrid FDOA-TDOA localization through extensive computer-based simulations.