Periodic time-varying Kalman filter equations for problems involving scanning sensors are solved using "lifting" techniques common for multirate systems. The solution to this problem is used to compare the performance of scanning sensors vs. stationary sensors in the estimation of cross-directional properties. Furthermore, controller performance is examined when the outputs from the Kalman filter are used as inputs to a state feedback control law. Although adding sensors may significantly enhance the estimates of cross-directional properties, feedback of these improved estimates may translate to lower levels of improvement in cross-directional variations.