Аннотация:In the full-scale OGRAN detector transfer of oscillatory displacements from end surfaces of the acoustic resonator to the Fabry-Perot cavity mirrors is considered. The elasticity of a mirror fastening element is taken into account. The mode in which mirror oscillation amplitude exceeds end surface amplitude is considered. Influence of the additional Boltzmann force is investigated. The influence of displacement measurer resolution to detector sensitivity is regarded. Phenomenological algorithm of data transformation is described; it realizes transformation of stochastic displacement spectral density into spectral density of metrics variations. A “reception band-width at the metric noise control level” is interpreted as a new characteristic. The corresponding characteristics of the GW detector “Ulitka” are calculated by the algorithm for comparison. The base analytic metric sensitivity algorithm using noise factor F is considered and modifications are made in it. It is generalized on area F ≤ 10; it allows to exclude forecasting values F < 1 and to determine a band of frequencies in which the detector potential sensitivity is realized (F ≤ 2). Noise factor expression is changed for taking into account a Pound-Drever-Hall technique and a FM discriminator. In addition to photoelectron shot noise contributions of laser radiation frequency and power fluctuations are presented