Overview of the radiometric and biophysical performance of the MODIS vegetation indices
Overview of the radiometric and biophysical performance of the MODIS vegetation indices
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DOI：
10.1016/s0034-4257(02)00096-2
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发表时间：
2002-11-01
影响因子：
13.5
通讯作者：
Ferreira, LG
中科院分区：
文献类型：
--
作者：
Huete, A;Didan, K;Ferreira, LG
我们评估了地球观测系统Terra平台上的中分辨率成像光谱仪(MODIS)最初12个月的植被指数产品可用性。在1公里和500米分辨率和16天合成周期下，得到了两个MODIS植被指数(VI)：归一化差异植被指数(NDVI)和增强型植被指数(EVI)。本文从辐射测量和生物物理角度对MODIS NDVI和EVI的性能进行了初步分析。我们使用现场密集型和区域广泛型相结合的方法来展示这两个指数的性能和有效性。我们的结果表明，航空测量的冠层顶部反射率和VI值与MODIS传感器在代表半干旱草/灌木、稀树草原和热带森林生物群的四个密集测量地点的VI值之间具有很好的一致性。同时获得的野外生物物理测量也证明了MODIS VI的科学用途。MODIS VIS在北美和南美洲许多生物群类型上的多时相剖面很好地代表了它们的季节性物候。MODIS-NDVI与NOAA-14 1公里AVHRR-NDVI时间剖面的比较表明，基于MODIS的指数表现出更高的保真度。给出了MODIS-VIS的动态范围，并对其在植被稀疏和密集地区区分植被差异的敏感性进行了评价。我们发现，在亚马逊等高生物量地区，NDVI逐渐饱和，而EVI对冠层变化仍然敏感。(C)2002 Elsevier Science Inc.保留所有权利。
We evaluated the initial 12 months of vegetation index product availability from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Earth Observing System-Terra platform. Two MODIS vegetation indices (VI), the normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI), are produced at 1-km and 500-m resolutions and 16-day compositing periods. This paper presents an initial analysis of the MODIS NDVI and EVI performance from both radiometric and biophysical perspectives. We utilize a combination of site-intensive and regionally extensive approaches to demonstrate the performance and validity of the two indices. Our results showed a good correspondence between airborne-measured, top-of-canopy reflectances and VI values with those from the MODIS sensor at four intensively measured test sites representing semi-arid grass/shrub, savanna, and tropical forest biomes. Simultaneously derived field biophysical measures also demonstrated the scientific utility of the MODIS VI. Multitemporal profiles of the MODIS VIs over numerous biome types in North and South America well represented their seasonal phenologies. Comparisons of the MODIS-NDVI with the NOAA-14, 1-km AVHRR-NDVI temporal profiles showed that the MODIS-based index performed with higher fidelity. The dynamic range of the MODIS VIs are presented and their sensitivities in discriminating vegetation differences are evaluated in sparse and dense vegetation areas. We found the NDVI to asymptotically saturate in high biomass regions such as in the Amazon while the EVI remained sensitive to canopy variations. (C) 2002 Elsevier Science Inc. All rights reserved.