A systematic intercalibration tool between multiband imaging and spot spectra datasets

A method has been developed to combine multiband imaging data with independent spot spectra. The method requires in input approximate spot sizes and locations within the image field, and the degrees of freedom on the spectra positioning and spot sizes. The algorithm determines the optimized solution among the overall set of possibilities. The method can be applied to both reflectance and scaled spectra. Sets of well-documented telescopic spectra have been used to produce refined calibration of Clementine UVVIS-NIR images on several lunar regions: Aristarchus, Apollo 17 and Reiner Gamma. The implementation of this methodology permits to reach a very high consistency between independent datasets of reference spectra and multispectral images, with absolute residuals less than 0.01 for each wavelength. In a broader use, it provides a systematic tool for assessing the level of maximal consistency between two independent observational datasets, taking into consideration both the instrumental and positioning uncertainties. It has immediate applications for intercalibration purposes, with the prospect of deriving an advanced determination of planetary regolith optical properties.