Passive localization of signal source based on UAVs in complex environment

For the influence caused by multipath fading and non-line-of-sight (NLOS) transmission, it is challenging to accurately localize a moving signal source in complex environment by using the wireless sensor network (WSN) on the ground. In this paper, we establish a special WSN in the sky to address this challenge, where each sensor is loaded on an unmanned aerial vehicle (UAV) and the operation center of all the UAVs is fixed on the ground. Based on the analyzing of the optimal distribution and the position error calibration of all the sensors, we formulate the localization scheme to estimate the position of the target source, which combines the time difference of arrival (TDOA) method and the frequency difference of arrival (FDOA) method. Then by employing the semidefinite programming approach, we accurately obtain the position and velocity of the signal source. In the simulation, the validity of the proposed method is verified through the performance comparison.