Academic Journal
High spatial resolution monitoring land surface energy, water and CO 2 fluxes from an Unmanned Aerial System
| العنوان: | High spatial resolution monitoring land surface energy, water and CO 2 fluxes from an Unmanned Aerial System |
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| المؤلفون: | Wang, Sheng, Garcia, Monica, Bauer-Gottwein, Peter, Jakobsen, Jakob, Zarco-Tejada, Pablo J., Bandini, Filippo, Paz, Verónica Sobejano, Ibrom, Andreas |
| المصدر: | Wang , S , Garcia , M , Bauer-Gottwein , P , Jakobsen , J , Zarco-Tejada , P J , Bandini , F , Paz , V S & Ibrom , A 2019 , ' High spatial resolution monitoring land surface energy, water and CO 2 fluxes from an Unmanned Aerial System ' , Remote Sensing of Environment , vol. 229 , pp. 14-31 . https://doi.org/10.1016/j.rse.2019.03.040 |
| سنة النشر: | 2019 |
| المجموعة: | Aarhus University: Research |
| مصطلحات موضوعية: | Eddy covariance, Evapotranspiration, Gross primary productivity, Instantaneous and diurnal, Optical and thermal remote sensing, Spatial heterogeneity |
| الوصف: | High spatial resolution maps of land surface energy, water and CO 2 fluxes, e.g. evapotranspiration (ET)and gross primary productivity (GPP), are important for agricultural monitoring, ecosystem and water resources management. However, it is not clear which is the optimal (e.g. coarsest possible)spatial resolution to capture those fluxes accurately. Unmanned Aerial Systems (UAS)can address this by collecting very high spatial resolution (<1 m, VHR)imagery. The objective of this study is to model ET and GPP dynamics using VHR optical and thermal imagery and quantify the influence of the spatial heterogeneity in the flux simulations and validations. The study was conducted at a deciduous willow bioenergy eddy covariance (EC)flux site in Denmark. Flight campaigns were conducted during the growing seasons of 2016 and 2017 with a hexacopter equipped with RGB, multispectral and thermal infrared cameras. A ‘top-down’ modeling approach consisting of the Priestley–Taylor Jet Propulsion Laboratory model and a light use efficiency model sharing the same canopy biophysical constraints was used to estimate ET and GPP. Model outputs were benchmarked by EC flux observations with the source weighted footprint. Our results indicate that our model can well estimate the instantaneous net radiation, ET, GPP, evaporative fraction, light use efficiency and water use efficiency with root-mean-square deviations (RMSD)of 31.6 W·m −2 , 41.2 W·m −2 , 3.12 μmol·C·m −2 ·s −1 , 0.08, 0.16 g·C·MJ −1 and 0.35 g·C·kg −1 , respectively. Further, it is found that using a footprint model to sample different areas of VHR imagery can be a tool to provide better diurnal estimates to benchmark with EC data. Moreover, these VHR maps (0.3 m)allowed us to quantify metrics of spatial heterogeneity by using semivariogram analysis and by aggregating model inputs into different spatial resolutions. For instance, we find that in this site, the aggregation of simulated GPP using the source weighted mean of the EC footprint was about 30% lower in RMSD than ... |
| نوع الوثيقة: | article in journal/newspaper |
| اللغة: | English |
| Relation: | https://pure.au.dk/portal/en/publications/73e4f6c8-3a84-4726-acf1-48a6060a4c85 |
| DOI: | 10.1016/j.rse.2019.03.040 |
| الاتاحة: | https://pure.au.dk/portal/en/publications/73e4f6c8-3a84-4726-acf1-48a6060a4c85 https://doi.org/10.1016/j.rse.2019.03.040 http://www.scopus.com/inward/record.url?scp=85065142510&partnerID=8YFLogxK |
| Rights: | info:eu-repo/semantics/openAccess |
| رقم الانضمام: | edsbas.51301E49 |
| قاعدة البيانات: | BASE |
| DOI: | 10.1016/j.rse.2019.03.040 |
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