Advances in optical earth observation for geological mapping : a Review
CITATION: Ngcofe, L. D. & Van Niekerk, A. 2016. Advances in optical earth observation for geological mapping : a Review. South African Journal of Geomatics, 5(1):1-16, doi:10.4314/sajg.v5i1.1.
The original publication is available at http://www.sajg.org.za
Recent increases in the availability of earth observation (EO) data and the advances made in its processing have opened up new opportunities for earth monitoring studies. This article reviews recent advances in EO, specifically in the optical domain, and comments on their potential for geological investigations. A review of the literature revealed that much work has been done on the use of multispectral to hyperspectral EO data for geological investigations, but that relatively little emphasis has been placed on the value of high spatial resolution in geological studies. From the literature it was found that geographic object based image analysis (GEOBIA) is a relatively new paradigm in remote sensing that has been shown to reduce the intra-class spectral variability in high spatial resolution imagery, thereby increasing image classification accuracies. It has been used for many applications, but relatively little research has been done on the application of GEOBIA for geological investigations. Another finding of this review is that the power of EO data increases substantially when different types of data are used (fused) together. Data fusion seizes the advantages of the capabilities of each sensor while reducing its limitations. By its nature, GEOBIA offers the ability to fuse disparate data sources and the review concludes that more research is required on the use of GEOBIA and data fusion of high resolution EO data for geological mapping.