Abstract:
The theory of Pugachev conditionally-optimal filtering and extrapolation of stochastic processes described by explicit stochastic differential equations at autocorrelated noise in observations is widely used in modern real-time information processing. The paper is devoted to implicit Gaussian stochastic systems (StS) reducible to explicit StS at observational autocorrelated noises. The main results are: ($i$) typical mathematical models of observable implicit StS reducible to differential explicit StS; ($ii$) basic equations for nonlinear conditionally-optimal filters (COF) and conditionally-optimal extrapolators (COE) at noncorrelated and autocorrelated noises; and ($iii$) illustrative examples for reducible StS. Main conclusions and perspective directions for COF and COE design in the case of implicit differential and functional differential StS are given.