“…Theorem 1 [1] (On decomposition of the stochastic process using an orthonormal basis) Let X(t), t ∈ T be stochastic process of the second order, EX(t) = 0 ∀t ∈ T , let B(t, s) = EX(t)X(s) be the correlation function of X, let f (t, λ) be some function from L 2 (Λ, µ) space, and let {g k (λ), k ∈ Z} be the orthonormal basis in L 2 (Λ, µ) space. Then, correlation function B(t, s) is represented in the form…”