Position measurement system, zeroing method, lithographic apparatus and device manufacturing method

A method for a position measurement system configured to measure a position of an object, the position measurement system comprising:

• a displacement interferometer having a first capture range;
• and
• a time-of-flight sensor having a second capture range that is larger than the first capture range and having an inaccuracy that is smaller than the first capture range,
• wherein the method comprises:
• determining a coarse position of the object within the second capture range using the time-of-flight sensor;
• and
• determining a fine position of the object using the displacement interferometer and the determined coarse position.

A position measurement system configured to measure a position of an object, the position measurement system comprising:

• a displacement interferometer having a first capture range;
• a time-of-flight sensor having a second capture range that is larger than the first capture range and having an inaccuracy that is smaller than the first capture range;
• and
• a processing system configured to at least:
• determine a coarse position of the object within the second capture range using the time-of-flight sensor;
• and
• determine a fine position of the object using the displacement interferometer and the determined coarse position.