A.V. Juravlev - Ph.D. (Eng.), Senior Research Scientist, chief designer - General Director Deputy of JSC NVP «PROTEK». E-mail: protek@protek-vrn.ru
V.V. Nerovny - Ph.D. (Eng.), Associate Professor Air Force Academy named after professor N.E. Zhukovsky and Y.A. Gagarin (Voronezh). E-mail: val.nerownyj@yandex.ru
A.V. Zemlyanuhkin - Air Force Academy named after professor N.E. Zhukovsky and Y.A. Gagarin (Voronezh)
A.V. Smolin - Leading Engineer of JSC NVP «PROTEK». E-mail: smolinalexe@yandex.ru

A mathematical model of probability definition of the navigation signal phase-lock-loop system tracking breakdown during the allowed time under the conditions of the signal-like jamming is given. The results of signal-like jamming effectiveness evaluation conditionally its parameters as applied to GLONASS users - equipment phase-lock-loop system using the civil signal are presented. The authors prove that the phase-lock-loop noise immunity effected by signal-like jamming decreases from 1 to 3 dB in comparison to the AWGN. The complexification of the phase-lock-loop with inertial navigation systems allows its 5-6 dB noise immunity increase under the conditions of signal-like jamming.