Remote Sensing of vegetation chlorophyll fluorescence across spatial and temporal scales

Abstract

This research is focused on understanding different aspects of passive remote sensing of vegetation chlorophyll fluorescence. The spatial scales in this dissertation range from plant level to the six biomes of Brazil. Observations were made at handheld to satellite level under actinic illumination and sunlight. The instrumentation platforms were handheld to satellite level. The temporal scales ranged from the seconds to years. The promise of chlorophyll fluorescence, and specifically solar-induced fluorescence, to infer plant functioning status is at the core of these studies. The responsiveness of solar-induced fluorescence to changing environmental conditions is what makes this quantity both desirable to monitor and complicated to interpret. These complexities require exploration of multiple techniques that transcend disciplinary boundaries, thus, this research incorporates numerous approaches and concepts necessary to further our understanding of plant functioning from passive remote sensing observations. The purpose of this dissertation is to exploit fully available spectral instrumentation by developing robust methods of characterizing chlorophyll fluorescence metrics. It is under this regime that I undertook a multi-instrument, interdisciplinary, and wide ranging examination of chlorophyll fluorescence at multiple timescales.