Analysis of Global LAI/FPAR Products from VIIRS and MODIS Sensors for Spatio-Temporal Consistency and Uncertainty from 2012–2016 | |
Baodong Xu1,2,3; Taejin Park2; Kai Yan2; Chi Chen2; Yelu Zeng4; Wanjuan Song2; Gaofei Yin5![]() | |
2018 | |
Source Publication | Forests
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ISSN | 1999-4907 |
Volume | 9Issue:2Pages:73 |
Contribution Rank | 5 |
Abstract | The operational Moderate Resolution Imaging Spectroradiometer (MODIS) Leaf Area Index (LAI) and Fraction of Photosynthetically Active Radiation absorbed by vegetation (FPAR) algorithm has been successfully implemented for Visible Infrared Imager Radiometer Suite (VIIRS) observations by optimizing a small set of configurable parameters in Look-Up-Tables (LUTs). Our preliminary evaluation showed reasonable agreement between VIIRS and MODIS LAI/FPAR retrievals. However, there is a need for a more comprehensive investigation to assure continuity of multi-sensor global LAI/FPAR time series, as the preliminary evaluation was spatiotemporally limited. In this study, we use a multi-year (2012–2016) global LAI/FPAR product generated from VIIRS and MODIS to evaluate for spatiotemporal consistency. We also quantify uncertainty of the product by utilizing available ground measurements. For both consistency and uncertainty evaluation, we account for variations in biome type and temporal resolution. Our results indicate that the LAI/FPAR retrievals from VIIRS and MODIS are consistent at different spatial (i.e., global and site) and temporal (i.e., 8-day, seasonal and annual) scales. The estimate of mean discrepancy (−0.006 ± 0.013 for LAI and −0.002 ± 0.002 for FPAR) meets the stability requirement for long-term LAI/FPAR Earth System Data Records (ESDRs) from multi-sensors as suggested by the Global Climate Observing System (GCOS). It is noteworthy that the rate of retrievals from the radiative transfer-based main algorithm is also comparable between two sensors. However, a relatively larger discrepancy over tropical forests was observed due to reflectance saturation and an unexpected interannual variation of main algorithm success was noticed due to instability in input surface reflectances. The uncertainties/relative uncertainties of VIIRS and MODIS LAI (FPAR) products assessed through comparisons to ground measurements are estimated to be 0.60/42.2% (0.10/24.4%) and 0.55/39.3% (0.11/26%), respectively. Note that the validated LAI were only distributed in low domains (~2.5), resulting in large relative uncertainty. Therefore, more ground measurements are needed to achieve a more comprehensive evaluation result of product uncertainty. The results presented here generally imbue confidence in the consistency between VIIRS and MODIS LAI/FPAR products and the feasibility of generating long-term multi-sensor LAI/FPAR ESDRs time series. |
Keyword | Viirs Leaf Area Index (Lai) Fraction Of Photosynthetically Active Radiation Absorbed By Vegetation (Fpar) Modis Consistency Uncertainty Evaluation |
DOI | 10.3390/f9020073 |
URL | 查看原文 |
Indexed By | SCI ; EI |
Language | 英语 |
WOS ID | WOS:000427520600026 |
Accession number | Accession number: 20180704789796 |
Citation statistics | |
Document Type | 期刊论文 |
Identifier | http://ir.imde.ac.cn/handle/131551/20885 |
Collection | 数字山地与遥感应用中心 |
Corresponding Author | Taejin Park |
Affiliation | 1.State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences, Beijing 100101, China 2.Department of Earth and Environment, Boston University, Boston, MA 02215, USA 3.University of Chinese Academy of Sciences, Beijing 100049, China 4.Department of Global Ecology, Carnegie Institution for Science, Stanford, CA 94305, USA 5.Institute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, China |
Recommended Citation GB/T 7714 | Baodong Xu,Taejin Park,Kai Yan,等. Analysis of Global LAI/FPAR Products from VIIRS and MODIS Sensors for Spatio-Temporal Consistency and Uncertainty from 2012–2016[J]. Forests,2018,9(2):73. |
APA | Baodong Xu.,Taejin Park.,Kai Yan.,Chi Chen.,Yelu Zeng.,...&Ranga B. Myneni.(2018).Analysis of Global LAI/FPAR Products from VIIRS and MODIS Sensors for Spatio-Temporal Consistency and Uncertainty from 2012–2016.Forests,9(2),73. |
MLA | Baodong Xu,et al."Analysis of Global LAI/FPAR Products from VIIRS and MODIS Sensors for Spatio-Temporal Consistency and Uncertainty from 2012–2016".Forests 9.2(2018):73. |
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