1. A method of tuning a first lithography system utilizing a reference lithography system, the first lithography system and the reference lithography system each having tunable parameters for controlling imaging performance, the method comprising: defining a test pattern and an imaging model; imaging the test pattern utilizing the reference lithography system and measuring the imaging results; imaging the test pattern utilizing the first lithography system and measuring the imaging results; calibrating the imaging model utilizing the imaging results corresponding to the reference lithography system, the calibrated imaging model having a first set of parameter values; tuning the calibrated imaging model utilizing the imaging results corresponding to the first lithography system, the tuned calibrated model having a second set of parameter values; and adjusting the parameters of the first lithography system based on a difference between the first set of parameter values and the second set of parameter values.