A New Technique for Infrared Remote Sensing Of Solar Induced Fluorescence and Reflectance from Vegetation Covers

Abstract

A new technique of remote sensing of solar-induced fluorescence and reflectance from vegetation covers  has been developed, radiant calibrated, and applied to investigate solar-induced infrared fluorescence (680-730 nm) and reflectance (750-1000 nm) from some tropical plants within the tropical peak summer period (in August) in Nigeria, for five days, taking readings at sun rise, midday and sunset , each day. The IR device used electronic filters and Fresnel lens to attenuate signals outside the spectral bands. The radiometric detection parameters of the device stood at; Responsivity of 1.5 x 10³¹ V/W, Noise Equivalent Power NEP of 6.48 x 10 ^-34 W, and Detectivity of 1.54 x 10³³ /W at 780 nm; Responsivity of 2.2 x 10³⁷ V/W, Noise Equivalent Power NEP of 4.45 x 10 ^-40 W, and Detectivity of 2.0 x 10³⁹ /W at 680 nm. The infrared fluorescence/reflectance for each plant canopy varied consistently with solar irradiance.

Keywords: Radiometry, Solar-Induced Fluorescence (SIF), Reflectance (SIR)