부산대학교 도서관

Several studies have demonstrated the influence of the spectral resolution (SR) on the retrieval of solar-induced chlorophyll fluorescence (SIF) from ground-based sensors with different spectral configurations. However, research studying the implications of the SR of airborne hyperspectral imagers on the retrieved SIF is lacking, and its interpretation is critical for precision agriculture, plant stress detection and phenotyping studies. This work investigates the effects of SR on SIF performance through the Fraunhofer Line Depth (FLD) principle at the O 2 -A absorption feature (760.4 nm) using two airborne hyperspectral imagers with different spectral characteristics. A sub-nanometer hyperspectral imager with 0.1-0.2 nm full-width at half-maximum (FWHM) resolution and a broader-band hyperspectral imager of 5.8 nm FWHM were flown in tandem. The campaigns were conducted over a winter wheat field with randomized experimental design, with plots receiving different nitrogen rates to ensure SIF variability. Results showed a bias on the SIF levels quantified by both airborne imagers $(\text{RMSE} =3.7$ mW/m 2 /nm/sr), but a strong relationship between both sensors at the O 2 -A absorption feature ($\mathrm{R}^{2}=0.84,\ \mathrm{p} < 0.001$). Results confirm the utility of hyperspectral imagers ca. 5 nm FWHM resolution for stress detection and plant phenotyping where assessing the relative variability of SIF across experimental plots is sought.