Iss ue in Brief

State estimation, identification, and stochastic problems are prominent in tills issue. These topics, like computational methods, indicate the wider range of interests which continue to develop in the general area of system control. New results on linear multi­ variable systems are given, and three interesting applications also demonstrate the broadness of the field: a strap down inertial navi­ gation system, a phased array tracking radar, and a synchronous motor control.