Transfer Spectral Libraries

sabki's picture

Dear All,

Which one is best method and what is each reason for transfering spectral libraries from NIR reference instruments to NIR micro phazir such as :

  • direct transfer
  • independent recalibration
  • subset augmentation
  • spectra transformation
  • model transformation
  • result transformation

Thanks & Regards,


dardenne's picture


‘Independent recalibration’ is the best way if all the samples (or samples covering the same variability) are still available to be scanned on the portable instrument. It is rarely the case.

‘ Direct transfer’ is only possible if the wavelength ranges and data spacing  are exactly the same. It will lead to corrections (bias & slope=‘results transformation’) with likely a loss of accuracy and the inefficiency of the outliers detection tools (H and Xres).

It remains ‘spectra transformation’ + ‘subset augmentation’ and recalibration in the new range. This way is the best approach to exploit historical data.

And do not forget a second independent test set to validate the final model.