Olivine exposures at the central peak of Copernicus crater of the Earth's Moon have been confirmed by telescope observations and Clementine spectra data.Using these exposures as training sites,this study used a method of combining two spectral indices(950?nm/750?nm and 2000?nm/1500?nm),one maturity index(Is/FeO),and four chemical content indices(FeO,Mg,Al,Ca),through a decision tree classifier,to map olivine-rich units on the west lunar surface based on mosaicked Clementine image(500 m pixel size).Most classified olivine exposures are found inside craters or on their rays,suggesting that olivine exposures are directly associated with the impact processes.The results have been validated in several selected sites,though further validations with data from the newest missions are strongly needed.
