TDOA localization of multiple disjoint sources based on a calibration emitter

The passive source localization accuracy can be greatly reduced due to the sensor position error. A localization algorithm using time difference of arrival (TDOA) for multiple disjoint sources was proposed, which improves the localization accuracy by means of a single calibration emitter. The sensor position error was first reduced by using the calibration emitter, and the corresponding error statistical knowledge was estimated. Then based on the updated sensor position, TDOA localization of multiple disjoint sources with high accuracy was realized by utilizing the algorithm of two-step weighted least squares (TS-WLS). The Cramer-Rao lower bound (CRLB) was theoretically derived to analyze the localization performance of the closed-form algorithm. And the theoretical derivation was validated by the simulations. The simulation results indicate that the localization accuracy of multiple disjoint sources is obviously improved by using calibration correction technique. Moreover, the solution performance is shown to reach the CRLB under small TDOA observation error and sensor position error. The developed estimator is computationally attractive because it does not require initial solution estimation and iterative computation. Furthermore, joint estimation between source positions and sensor positions is not needed, which reduces the calculation amount.