Performance bounds for target identification using decay rates estimates from EMI measurements

Decay rate estimation has been proposed as an effective method for landmine and unexploded ordnance (UXO) detection. The physical basis for this strategy is that every object in the target library possesses a unique set of decay rates. In theory, the characteristic decay rates can be estimated from the measured electromagnetic induction (EMI) response, and then utilized for target detection and subsequent identification. Unfortunately, decay rate estimation is notoriously difficult and this difficulty adversely impacts target identification performance. Since the basis for this approach to target detection and identification is that targets are uniquely characterized by their decay rates, discrimination performance is dependent upon decay rate estimation performance. The Cramer-Rao lower bound (CRLB) for decay rate and amplitude coefficient estimates is utilized to investigate the fundamental limitations on target identification via decay rate estimation. It is shown how both the temporal sampling strategy and the number of poles being estimated affects pole estimation and target identification performance.