NDVI Analysis of Photosynthetic Activity of Plants Grown in Sulfate Enriched Martian Simulant JSC-1*

We examine the relative health of plants grown in sulfate enriched versions of Martian simulant JSC-1 using modified models of the Normalized Difference Vegetation Index, NDVI, developed for satellite imagery following the Beisel – Anderson model.  The NDVI method relies on a differential comparison of the visible and near infrared light reflection from a plant as an indicator of the chlorophyll mediated photosynthetic activity.  Extensions of this method allow for adaptations to standard digital CCD cameras. We examined Martian simulant JSC-1 with controlled alkaline earth hydrated sulfate additives, especially magnesium sulfates, to match the Mars ChemCam and lab Raman spectral analysis of soil composition near Pahrump Hills and Gale crater.   Using Mathematica based image analysis algorithms we separated images into a wavelength series so that weighted functional composites of red and green based differential comparisons could be made as in the RDVI and GDVI modes.  We develop an analytical model using histogram, wavelength, and contrast controls to explore the optimization of the index, wavelength weights, JSC-1 mix and fractional area density coverage for the plants.   We find positive correlations for hydrated magnesium sulfates coupled to the weighted RDVI functions.