On rank of block Hankel matrix for 2-D frequency detection and estimation

For detection and estimation of 2-D frequencies from a 2-D array of data using a subspace decomposition method, one needs to construct a block Hankel matrix. For reliable detection and estimation, the rank of the block Hankel matrix should be made equal to the number of 2-D frequencies inherent in the data in the absence of noise. In this work, we provide the conditions for achieving the desired rank