New Approach for Calibration Transfer from a Local Database to a Global Database

Abstract

The goal of the experiment is to transfer a local model to a global model for the prediction of a new parameter. Station de Haute Belgique (SHB) has developed an extensive spectral database to determine 10 parameters of whole plant maize silage samples. Pioneer has determined the Tilley and Terry digestibility (T&T) on a smaller set of samples. The analysis of the Mahalanobis distances between the two sets shows that Pioneer's set has a much smaller variation than SHB's set. Pioneer's set can be predicted by SHB's calibrations, but SHB's database cannot be predicted by Pioneer's calibration. The 10 parameters predicted on Pioneer's set are used to estimate the Tilley and Terry digestibility coefficient through a PLS model. The same model is then used to predict T&T on the large SHB set. The later predicted values are reported as references on SHB's set and a global T&T equation is developed after an adequate sample selection. The procedure shows that the new equation, applied on independent sets, is more accurate and more robust than the local one.