Accuracy of 2-Dimensional Object Location Estimation Using Leaky Coaxial Cables

The improvement of position estimation accuracy is a very important factor in various radar applications. This paper focuses on two-dimensional (2-D) location estimation in radar surveillance using leaky coaxial cables. A leaky coaxial cable is a kind of antenna and has recently attracted attention as a powerful tool for vehicle detection and as an intrusion detection sensor for perimeter security. We derive the Cramér-Rao bound (CRB) for a leaky coaxial cable sensing application and introduce the CRB ellipsoid to evaluate the accuracy of the 2-D location estimation of an object. The diameter and angle of a CRB ellipsoid indicates its error distribution. A leaky coaxial cable has an outer conductor with periodic slots. Its slot pattern determines the radiation characteristics such as the beam angle and harmonic radiation. We focus on the slot pattern to improve the estimation accuracy. Numerical analyses show that a slot pattern generating multi-beams improves the accuracy while single radiation is preferred for general use in communication applications.