Lithographic method

A method of optimizing measurement data from a sensor system configured for measuring a property of a substrate, the method comprising:

• obtaining overlay data for a plurality of substrates, wherein the overlay represents a deviation between a measured and an expected position of an alignment marker on a substrate and comprises a plurality of measurements of the alignment marker position made by a sensor system, each measurement of the plurality of measurements utilizing a different value of the operational parameter and/or a different operational parameter of the sensor system;
• based on the obtained overlay data, and for each of the different values of the operational parameter and/or different operational parameters, determining a weight for adjusting the measurements obtained utilizing the different values of the operational parameter and/or different operational parameters such that the weighted adjustments to the measurements made by the sensor system for all of the different values of the operational parameter and/or different operational parameters are combined to minimize the overlay.

A non-transitory computer-readable medium comprising computer-readable instructions therein, the instructions, upon execution by a computer system, configured to cause the computer system to at least:

• obtain overlay data for a plurality of substrates, wherein the overlay represents a deviation between a measured and an expected position of an alignment marker on a substrate and comprises a plurality of measurements of the alignment marker position made by a sensor system configured for measuring a property of a substrate, each measurement of the plurality of measurements utilizing a different value of the operational parameter and/or a different operational parameter of the sensor system;
• based on the obtained overlay data, and for each of the different values of the operational parameter and/or different operational parameters, determine a weight for adjusting the measurements obtained utilizing the different values of the operational parameter and/or different operational parameters such that the weighted adjustments to the measurements made by the sensor system for all of the different values of the operational parameter and/or different operational parameters are combined to minimize the overlay.