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 Cramér-Rao lower bound (CRLB). In this paper, Barankln 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 Barankln bound suggests that although asymptotic localization performance degrades with increasing environmental uncertainty, the threshold SNR is relatively unaffected.