. "In this paper, extended sliding mode observer is used for estimating of target maneuver for applying of augmented
proportional navigation in terminal guidance phase of homing interceptors. Implementation of augmented proportional
navigation is dependent on estimation target acceleration. Nonlinear estimation of target acceleration is desired, because
of nonlinear engagement geometry in terminal phase. Therefore in this", Aerospace Mechanics, 13, 4, 2018, 1-10.