V.V. Rodionov - D.Sc. (Eng.), Professor, Academician of Academy of Sciences of Applied Radio electronics;Professor of South Ural State University (National Research University);Head of Scientific and Technical Centre of JSC - Chelyabinsk radioplant "Polyot". E-mail: rodionov@polyot.ru
A.Ju. Svetlov - Ph.D. (Eng.), Associate Professor of Department "Radioengineering" of branch of South Ural State University (National Research University) (Kyshtym), Head of KB-29 Design Bureau JSC - Chelyabinsk radioplant "Polyot". E-mail: aysv@mail.ru

This paper considers the noise-immunity of algorithms to detect synthesized for useful models incoherent signal and Gaussian interference, in relation to the coherent pulse radar air traffic control system. The algorithm is sub-optimal in relation to the optimal algorithm of detection quasideterministic signal on the background of Gaussian clutter. Feature of suboptimal algorithm is the presence of prethreshold statistics of eigenvalues and eigenvectors of the correlation matrix inter-period fluctuations passive interference. For the practical implementation of adaptive options suboptimal algorithm is selected class interference, for which the adaptation, in the form of the expansion of the correlation matrix inter-period fluctuations of interference with the system of eigenvalues and eigenvectors, where the eigenvector chosen in advance, and the eigenvalues are estimated for the training set. Results of numerical calculations and simulations indicate that, in practice it is enough to have the number of data points, equal to 25 and loss of signal-to-noise ratio adaptive algorithm compared with the optimum amount to 3 dB.