A metrology system comprising: a controller, the controller including one or more processors configured to execute program instructions causing the one or more processors to: receive a model for measuring one or more selected attributes of a target including one or more features distributed in a selected pattern based on regression of spectroscopic scatterometry data from a scatterometry tool for a selected range of wavelengths; generate a weighting function for the model to de-emphasize portions of the spectroscopic scatterometry data associated with one or more wavelengths within the selected range of wavelengths at which light captured by the scatterometry tool when measuring the target is predicted to include one or more undesired diffraction orders; direct the spectroscopic scatterometry tool to generate scatterometry data of one or more measurement targets for the selected range of wavelengths, wherein the one or more measurement targets include fabricated features distributed in the selected pattern; and measure the one or more selected attributes for the one or more measurement targets based on regression of the scatterometry data of the one or more measurement targets to the model weighted by the weighting function. a controller, the controller including one or more processors configured to execute program instructions causing the one or more processors to: receive a model for measuring one or more selected attributes of a target including one or more features distributed in a selected pattern based on regression of spectroscopic scatterometry data from a scatterometry tool for a selected range of wavelengths; generate a weighting function for the model to de-emphasize portions of the spectroscopic scatterometry data associated with one or more wavelengths within the selected range of wavelengths at which light captured by the scatterometry tool when measuring the target is predicted to include one or more undesired diffraction orders; direct the spectroscopic scatterometry tool to generate scatterometry data of one or more measurement targets for the selected range of wavelengths, wherein the one or more measurement targets include fabricated features distributed in the selected pattern; and measure the one or more selected attributes for the one or more measurement targets based on regression of the scatterometry data of the one or more measurement targets to the model weighted by the weighting function. receive a model for measuring one or more selected attributes of a target including one or more features distributed in a selected pattern based on regression of spectroscopic scatterometry data from a scatterometry tool for a selected range of wavelengths; generate a weighting function for the model to de-emphasize portions of the spectroscopic scatterometry data associated with one or more wavelengths within the selected range of wavelengths at which light captured by the scatterometry tool when measuring the target is predicted to include one or more undesired diffraction orders; direct the spectroscopic scatterometry tool to generate scatterometry data of one or more measurement targets for the selected range of wavelengths, wherein the one or more measurement targets include fabricated features distributed in the selected pattern; and measure the one or more selected attributes for the one or more measurement targets based on regression of the scatterometry data of the one or more measurement targets to the model weighted by the weighting function.