Woodgate William, van Gorsel Eva, Hughes Dale, Suarez Lola, Jimenez-Berni Jose, Held Alex
Commonwealth Scientific and Industrial Research Organisation, CSIRO, Building 801, Black Mountain, ACT 2601 Australia.
School of Earth and Environmental Sciences, The University of Queensland, Brisbane, QLD 4067 Australia.
Plant Methods. 2020 Jul 31;16:105. doi: 10.1186/s13007-020-00646-w. eCollection 2020.
Earth Observation 'EO' remote sensing technology development enables original insights into vegetation function and health at ever finer temporal, spectral and spatial resolution. Research sites equipped with monitoring infrastructure such as flux towers operate at a key bridging scale between satellite platform measurements and on-the-ground leaf-level processes.
This paper presents the technical details of the design and operation of a proximal observation system 'THEMS' that generates unattended long-term high quality thermal and hyperspectral images of a forest canopy on a short (sub-daily) timescale. The primary purpose of the system is to measure canopy temperature, spectral reflectance and radiance coincident with a highly instrumented flux tower site for benchmarking purposes. Basic system capability is demonstrated through low level data product descriptions of the high-resolution multi-angular imagery and ancillary data streams. The system has been successfully operational for more than 2 years with little to no intervention.
These data can then be used to derive remotely sensed proxies of canopy and ecosystem function to study temporal forest dynamics over a wide range of wavelengths, spatial scales (individual trees to canopy), and temporal scales (minutes to multiple years). The multi-purpose system is intended to provide unprecedented spatio-temporal ecophysiological insight and to underpin upscaling of remotely sensed dynamic ecosystem water, CO, and energy exchange processes.
对地观测“EO”遥感技术的发展使得能够以越来越精细的时间、光谱和空间分辨率对植被功能和健康状况进行深入洞察。配备了诸如通量塔等监测基础设施的研究站点在卫星平台测量与地面叶片水平过程之间的关键桥梁尺度上运行。
本文介绍了近端观测系统“THEMS”的设计和运行技术细节，该系统能在短（亚日）时间尺度上生成森林冠层的无人值守长期高质量热图像和高光谱图像。该系统的主要目的是测量与配备高度仪器的通量塔站点同步的冠层温度、光谱反射率和辐射率，用于基准测试。通过对高分辨率多角度图像和辅助数据流的低层次数据产品描述展示了基本系统能力。该系统已成功运行两年多，几乎无需干预。
这些数据随后可用于推导冠层和生态系统功能的遥感代理指标，以研究广泛波长范围、空间尺度（从单棵树到冠层）和时间尺度（从分钟到多年）上的森林动态变化。该多功能系统旨在提供前所未有的时空生态生理洞察，并为遥感动态生态系统水、二氧化碳和能量交换过程的尺度扩展提供支持。
