Abstract. A combination of an optical integrating sphere and leaf chamber is described, and some principles of its design are given. It is shown that the number of quanta absorbed by the leaf inside the sphere can be found from measurements of the quantum flux density inside the sphere with and without the leaf present, when certain constant parameters of the sphere are known. Methods for finding these are given. It is not necessary to know leaf area or absorptivity for the quantum yield for photosynthesis to be derived from additional measurement of CO2, fixation.
ABSTRACT:Owing to the limited payload capacities of most UAV platforms within an academic research budget, many UAV systems utilize commercial RGB cameras or modified sensors with some capacity for sensing in the NIR. However, many applications require higher spectral fidelity that only hyperspectral sensors can offer. For instance, the Photochemical Reflectance Index relies upon the narrow band absorbance of xanthophyll pigments at 531 and 570nm to quantify photosynthetic light use efficiency which are important indicators of productivity and stress in agricultural and forest ecosystems. Thus, our research group has been working on building a research paradigm around a commercial off-the-shelf hyperspectral sensor and UAV. This paper discusses some of the key decisions made regarding selection of equipment and navigating the regulatory and logistical landmines. The imagery collected to date and the options available to process and utilize hyperspectral data are discussed at the end.
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