Time Offset Estimation in Distributed TDOA-Based Direction Finding Systems

Distributed direction finding systems based on time difference of arrival (TDOA) present several advantages compared to traditional methods such as interferometry. These systems offer a dynamic array manifold structure, robust mobility, absence of uncertainty issues, non-dependence on the frequency or wavelength of the incoming signal for estimation performance, and the ability to enhance estimation performance by increasing the distance between sensors. However, the distributed nature of these systems brings forth certain challenges. Each sensor operates on its local clock, naturally resulting in offsets and deviations between clocks. Additionally, there is a necessity for wireless communication among sensors. This article proposes a method for estimating time offsets between distributed sensors and consequently improving the direction-finding performance. Simulation results demonstrate that the proposed method significantly enhances angle estimation.