Wide-band pulse-echo imaging with distributed apertures in multi-path environments

We derive a new image reconstruction method for distributed apertures operating in complex environments with additive non-stationary noise. Our method is capable of exploiting information that we might have about: multi-path scattering in the environment; statistics of the objects to be imaged; statistics of the additive non-stationary noise. The aperture elements are distributed spatially in an arbitrary fashion, and can be several hundred wavelengths apart. Furthermore, our method facilitates multiple transmit apertures which operate simultaneously, and is thus capable of handling a true multi-transmit-multi-receive scenario. The implementation of our reconstruction takes the form of a filter bank which is applied to the pulse-echo measurements. This processing can be performed independently on the measurements obtained from each receiving element. Our approach is therefore well suited for parallel implementation, and can be performed in a distributed manner in order to reduce the required communication bandwidth between each receiver and the location where the results are merged into the final image.