Fundamental limits and simulations on time difference of arrival source localization using ultrasound signals

A catheter-mounted transducer transmits a signal that is received by a widely-spaced array of single element transducers. The signal time or time difference of arrival values at the transducers estimate the catheter position. System signal and noise characteristics dictate the lower bound jitter values for time delay estimates. Transducer placement in relation to the catheter dictates Dilution of Precision (DOP) values. DOP is the Cramer-Rao lower bound on position estimates given equal variance zero mean Gaussian errors. It multiplies jitter values to provide a volume of uncertainty for position estimation. This work presents simulations of several system configurations and evaluates the location tracking performance of a least-squared estimator.