High-resolution coherent reflector location with multi-frequency active virtual arrays

We present a method to improve high-resolution imaging of coherent point reflectors with transmit/receive arrays. The data obtained from the array can be rearranged into a virtual data matrix to resolve additional reflectors. The problem with using a virtual array is that it may not necessarily be able to resolve coherent reflectors due to a rank deficiency in the source correlation matrix.We use the idea of array interpolation to allow for more coherent reflectors to be resolved than conventional techniques by averaging over multiple frequencies. Averaging over multiple frequencies allows for an effective full-rank source correlation matrix.