1. A control system configured to estimate for estimating a position in N dimensions of a point of interest on an object in a lithographic apparatus, where N is a positive integer, the system comprising: a measurement module configured to obtain M measurements, the M measurements relating to one or more measurement points on the object and at least one of the measurement points being displaced from the point of interest, M being a positive integer greater than N; and a transformation module configured to convert the M measurements into N positional estimate values representing an estimate of the position in the N dimensions of the point of interest, taking into account only static and low-frequency contributions of non-rigid body modes of the object.