Matched Field Processing Framework for Coherent Detection Over Local and Regional Networks (Postprint)

摘要

The objective of this study has been to develop a data-adaptive matched field procedure to detect coherently and incoherently across networks of stations at local and regional distances. The detector extends the single- phase matched field processing approach to detection using the entire waveform. The procedure is based upon a narrowband signal representation that exposes the invariant spatial and temporal correlation structure of network signals from repeating sources. The matched field detector is referred to as an incoherent detector (spatially coherent over a receiver aperture, but temporally incoherent due to the incoherent summation over the narrow frequency bands) and is optimal for sources displaying significant variation in the source time function from event to event. The framework is designed to adapt to the statistics of source time histories for any given target and employs an exponential age-weighting approach to effectively monitor evolving sources, such as open-cast mines. For a given source of interest, an initial detector is formed. If only a single observation is available, the detector can be either a rank-1 coherent detector (a correlator) or an incoherent detector. If multiple observations are available, an event ensemble can be formed, allowing higher rank subspace detectors.