Barankin bounds for source localization in an uncertain ocean environment

Ambiguity surfaces for underwater acoustic matched-field processing are prone to having high secondary peaks. This leads to anomalous source localization estimates below a threshold signal-to-noise ratio (SNR) at which the performance rapidly departs from that predicted by the Cramer-Rao lower bound (CRLB). In this paper, Barankin bounds are used to predict the threshold SNR under two different models including known or uncertain shallow-water environments and monochromatic or random narrowband sources. Evaluation of the Barankin bound suggests that although asymptotic localization performance degrades with increasing environmental uncertainty, the threshold SNR is relatively unaffected.