Using RGB Cameras to Classify Minerals in Rocks

Color is an uncertain characteristic for the determination of minerals. Many minerals occur in a variety of different colors. Examples are quartz with its color variants amethyst, rose quartz or smoky quartz or feldspar with color variants like amazonite. However, if the minerals in a rock are reliably determined, their different coloring can be used to quantify them. In this example we use a simple RGB photo taken with a smartphone to determine the amounts of quartz, plagioclase, alkali feldspar and dark minerals such as biotite and hornblende in granite. To facilitate the differentiation of minerals, we use a principal component analysis (PCA), which is also used to unmix and classify spectral images such as satellite images (Trauth, 2020).

Evolutionary Lomb-Scargle Power Spectral Analysis with MATLAB

In paleoclimate time series amplitude of spectral peaks usually varies with time. Evolutionary power spectral analysis such as the FFT-based spectrogram and wavelet power spectral analysis helps. These methods, however, require interpolation of the time series to a grid of evenly-spaced times. Instead we can use the Lomb-Scargle Method for unevenly-spaced spectral analysis, computed for a sliding window, to map changes of the cyclicities through time.

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50th and 51st Shortcourse on MRES – Interactive Online Seminars

During the worldwide SARS-CoV-2 pandemic, teaching at universities changed fundamentally within a few days. This also has an impact on the traditional MRES compact courses, which are now offered entirely online! The interactive online seminar on MATLAB Recipes for Earth Sciences will be held on 14–18 September 2020 (in English language) and 28 September–2 October 2020 (in German language).

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