Lithological discrimination in central Snowdonia using airborne multispectral scanner imagery†

An evaluation has been carried out of the use of 11-channel airborne multispectral scanner data as an input to large-scale geological mapping in upland Britain. The optimum index factor (OIF) provides a ranking of possible three-band combinations in terms of their uncorrelated spectral data content, while principal components analysis may be used to compress multi-channel data, thereby minimizing information loss. An assessment of the geological information content of various imagery products concluded that both high-value OIF and principal component images were useful for lithological discrimination of solid and superficial deposits whereas aerial photographs were better for identifying structural features.