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** Description:** The method of evaluation of basic probabilistic indexes of quality of accompaniment of aerodynamic objects facilities of radio-location is offered for the criteria of plot of trajectory and accompaniment M from N. A method is based on the construction of trees of events, that enables to build the complete group of events for any depth of analysis and conduct the calculation of such probabilities: plot of trajectory, its accompaniment and derangement from accompaniment. Exactness of the got results depends on the depth of construction of tree of events. At the depth of construction 2N the tests of the offered method good convergence of the expected results with the results of mathematical experiment.

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Keywords:
** events tree, probabilities of trajectory begin track and its accompaniment without derangements

Baturynskyi, M.P. (2008), “Vykorystannia derev podii dlia otsiniuvannia ymovirnostei zaviazky traiektorii ta yii suprovodzhennia bez zryviv zasobamy radiolokatsii”,