Spectrum and flat spectral line representation: geometric approach

A geometric approach to spectrum representation is presented. Spectrum representation is given for both uncorrelated and correlated noise environments. Conventional, high-resolution, and super-resolution spectra are unified. Flat spectra line representation is introduced for linear arrays. Several flat spectra line representations are given for both correlated and uncorrelated noise. The concept of the functional-J transformation of the cross-spectral density matrix is introduced for the flat-spectral-line representation.<>