Localization of weak objects in reverberant fields using waveform inversion

Abstract

This paper presents an application of the Waveform inversion approach to localization of objects in reverberant fields and with limited spatial measurements. Reverberant fields in enclosures can potentially carry useful information, however, in an incoherent way. Incoherency comes from the consecutive reflections of the wave energy several times in the domain. This, along with diffraction and dispersion effects, can ultimately lead to mixing of the wave energy in a seemingly random way. However, spreading of the wave energy can lead to multiple interrogations of each point in the enclosure. Hence, any substructural changes in the enclosure can be sensed with sufficient information carried by the wave energy flow. Furthermore, the temporal information buried in the data makes it feasible to conduct only a few spatial measurements. The authors present a localization scheme that benefits from the reverberant field and can reduce the required number of spatial measurements.