Author:Debba, PraveshDate:Jul 2009This paper evaluates a spectral unmixing method for estimating the partial abundance of spectrally similar minerals in complex mixtures. The method requires formulation of a linear function of individual spectra of individual minerals. The ...Read more
Author:Debba, Pravesh; Maina, J; Willemse, EDate:Nov 2010This paper reports on the results from ordinary least squares and ridge regression as statistical methods, and is compared to numerical optimization methods such as the stochastic method for global optimization, simulated annealing, particle ...Read more
Author:Debba, PraveshDate:Jul 2009This presentation presented to the SASA Eastern Cape Chapter at Rhodes University posses two questions: (a) how could estimates of abundances of spectrally similar iron-bearing oxide/hydroxide/sulfate minerals in complex mixtures be obtained ...Read more
Author:Debba, Pravesh; Carranza, EJM; Stein, A; Van der Meer, FDDate:Jul 2009The paper describes a novice method for sampling geochemicals to characterize mine tailings. The author’s model the spatial relationships between a multi-element signature and, as covariates, abundance estimates of secondary iron-bearing ...Read more
Author:Debba, PraveshDate:2009Most spectral unmixing techniques are variants of algorithms involving matrix inversion. Major problem in spectral unmixing is the non-orthogonality of end-members. The ability to estimate abundances in complex mixtures through spectral ...Read more
Author:Debba, PraveshDate:2009Most spectral unmixing techniques are variants of algorithms involving matrix inversion. Major problem in spectral unmixing is the non-orthogonality of end-members. The ability to estimate abundances in complex mixtures through spectral ...Read more
Author:Debba, Pravesh; Cho, Moses A; Mathieu, Renaud SADate:Jul 2009In this paper, a comparison is made through evaluating the within and between-class species variability for the original, the first derivative and second derivative spectra. For each, the experiment was conducted (i) over the entire electromagnetic ...Read more