A computer implemented method, comprising: measuring a coated surface with a spectrophotometer to obtain spectral reflectance data comprising each specific angle and wavelength combinations ; obtaining, using a processor, the spectral reflectance data of multiple measurements from the coated surface having a target coating thereon; determining, using the processor, whether the spectral reflectance data includes any outlier data points, wherein determining whether the spectral reflectance data includes any outlier data points includes: calculating a statistical outlier test of the multiple measurements of the spectral reflectance data at each specific angle and wavelength combination for the multiple measurements, determining a total number of potential statistical outliers associated with the spectral reflectance data at each angle and wavelength combination for each measurement, and when the total number of potential statistical outliers for a particular measurement exceeds a tolerance, marking the particular measurement for exclusion; removing, using the processor, at least a portion of the multiple measurements of the spectral reflectance data that are not marked for exclusion but that fall outside of a pre-defined acceptable tolerance range to produce final spectral reflectance data; and calculating, using the processor, a characteristic of the target coating based at least in part on the final spectral reflectance data . obtaining, using a processor, the spectral reflectance data of multiple measurements from the coated surface having a target coating thereon; determining, using the processor, whether the spectral reflectance data includes any outlier data points, wherein determining whether the spectral reflectance data includes any outlier data points includes: calculating a statistical outlier test of the multiple measurements of the spectral reflectance data at each specific angle and wavelength combination for the multiple measurements, determining a total number of potential statistical outliers associated with the spectral reflectance data at each angle and wavelength combination for each measurement, and when the total number of potential statistical outliers for a particular measurement exceeds a tolerance, marking the particular measurement for exclusion; calculating a statistical outlier test of the multiple measurements of the spectral reflectance data at each specific angle and wavelength combination for the multiple measurements, determining a total number of potential statistical outliers associated with the spectral reflectance data at each angle and wavelength combination for each measurement, and when the total number of potential statistical outliers for a particular measurement exceeds a tolerance, marking the particular measurement for exclusion; removing, using the processor, at least a portion of the multiple measurements of the spectral reflectance data that are not marked for exclusion but that fall outside of a pre-defined acceptable tolerance range to produce final spectral reflectance data; and calculating, using the processor, a characteristic of the target coating based at least in part on the final spectral reflectance data . <EOS>