why is xt considered as state variable what is the state of a variable how to filter out state variables kalman filter p and k is xt a state variable what are the state variables in kalman filtering why do we need a kalman filter when we have an observable that depend on lagged observations? is x,t,y and y state variables when is xt a state variable why kalman filter is used can state variables be filtered out why is a state variable in an ark filter used is xt a state variable if x is a condition of an observable that depends on a lagged observation, then what is the state variable? which state variables must be filtered out when can a state variable be used for an observable which state variable is known in kalman algorithm? what state variables must also be known which state variable does x(t) depend on can a state variable be a state variable