A measurement system configured to measure a position dependent signal of an object table, the measurement system including at least one sensor mountable on the object table and a sensor target object mountable on a substantially stationary frame, and a mounting device configured to mount the sensor target object on the substantially stationary frame, wherein the measurement system further includes a compensator configured to compensate movements and/or deformations of the sensor target object with respect to the substantially stationary frame. The compensator may include a passive or an active damper and/or a feedback position controller. In an alternative embodiment, the compensator includes a gripping device which fixes the position of the sensor target object during a high accuracy movement of the movable object.