1. A computer implemented method, comprising: obtaining, using a processor, spectral reflectance data from a coated surface having a target coating theron; determining, using the processor, whether the data includes any outlier data points; removing, using the processor, at least one of the outlier data points 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.