Robust sequential detection of narrowband acoustic signals in noise

Given only the outputs from a discrete Fourier transform (DFT) a robust sequential detector (RSD) for weak signals is derived based on m-interval partitioning. A loglikelihood ratio at the output of the DFT is formulated assuming knowledge of a set of quantiles and scores of the unknown and possible changing noise distribution. The quantiles and scores are chosen to minimize the average time to a decision under practical implementation constraints.