A high-resolution spectrum estimating algorithm has been developed. The proposed algorithm is based on approximation of maximum likelihood criterion, which leads to two-channel structure of the estimation filter. The first channel corresponds to a measuring channel like one of Capon's algorithm, and the second one is using for taking into account and compensation of non-coherent white noise component value. The developed algorithm is a compromise solution of the simplicity of DSP-realisation of Capon's or