A.D. Vinogradov, I.S. Dmitriev, M.P. Slichenko, E.S. Solomko
The maximum likelihood algorithm of joint direction finding, detection and estimation of amplitude of electric field of plane monochromatic radio wave is synthesized for monopulse radio direction finder with array antenna of arbitrary configuration. Conditions of a priori indeterminate form concerning equal intensity on magnitude of internal noise of channels of the receiver of direction finding are applicable. As a result of maximization of the relation of likelihood on unknown parameters as well as the likelihood equation solution, the maximum likehood estimations of intensity of internal noise and amplitudes of electric field of incoming radio wave are found. The structure of a solving rule of joint detection and direction finding is gained, and analytical forms for detection characteristics are found. The synthesized adaptive algorithm allows calculation which is insensitive to unknown intensity of noise threshold level of detection of plane radio-wave, providing constant level of probability of false alarms. The received analytical representations of characteristics of detection will well be co-ordinate with the data received as a result of statistical modeling on the computer of algorithm of joint detection and direction finding of plane monochromatic radio-wave. Expressions for dispersions of asymptotic not displaced estimations of direction of arrival and amplitudes of electric field of an accepted radio wave are gained. Loss in characteristics of adaptive detection in comparison with traditional on instances of direction finders with five-element and seven-element ring arrays with the no interacting not directed dipoles is analyzed. It is shown that loss in parameters of efficiency of adaptive algorithm of detection in comparison with traditional decreases with growth of quantity of measurements of complex amplitudes of voltage on exits of elements of antenna array, number of its reception elements, and also with increase relations a signal/noise and demanded probability of a false alarm.