Fast implementation of two-dimensional APES and CAPON spectral estimators

The matched-filterbank spectral estimators APES and CAPON have received considerable attention in a number of applications. Unfortunately, their computational complexity tends to limit their usage in several cases-a problem that has previously been addressed by different authors. In this paper, we introduce a novel method to the computation of the 1D and 2D APES and CAPON spectra, which is considerably faster than all existing techniques. Numerical examples are provided to demonstrate the application of APES to synthetic aperture radar (SAR) imaging, and to illustrate the reduction in computational complexity provided by our implementation.