Objective of Broadband Focusing Through a Focus Transformation Matrix
The purpose of broadband focusing is to transform data across different frequency bands into data at a common center frequency using a focus transformation matrix, thereby constructing a correlation matrix. The key element lies in the selection of the focus matrix, where different choices correspond to distinct algorithms. In implementation, this involves computing covariance matrices for each frequency sub-band and applying frequency-dependent focusing matrices to align signal subspaces before coherently averaging them.