Time-delay estimation for TOA-based localization of multiple sensors

In many applications using multiple sensors, knowledge of the relative positions of the sensors is required. The locations of the sensors can be obtained from measured time-of-arrivals (TOAs) of events generated by sources. Although several TOA-based localization techniques exist, practical TOA measurements are incomplete because they include an unknown internal delay; the time taken from the signal reaching the sensor to that it is registered as received by the capturing device. In order to localize the sensors properly, these internal delays need to be estimated accurately. In this paper we propose a method for estimating the internal delays by using a data fitting technique based on structured total least squares. Under reasonable assumptions we show that the algorithm is guaranteed to converge to the optimal solution and ultimately achieves a quadratic rate of convergence. Experimental results show that the execution time is less than 1% of the execution time of existing methods while attaining an even higher accuracy.