Model of Bistatic Measurement for Radius Estimation of Circular Cylinder

This letter presents a method of radius estimation in a case where a single circular scatterer is probed with a bistatic wireless system. The analysis uses a precise full-wave electromagnetic model for the scatterer. Because the circular geometry falls within a class of canonical shapes for which the Helmholtz equation is separable, a precise analytical formula for the scattered field is available. We demonstrate a way to derive the analytical expression of the Cramér–Rao lower bound (CRLB) for the variance of the radius estimator on the basis of the analytical solution to the electromagnetic scattering problem. We compute a radius estimate with our customized numerical optimization algorithm, which is shown to perform well for the present optimization problem. We compare the performance of the numerically computed estimator with the CRLB.