Comparison of active and passive spectral sensors in discriminating biomass parameters and nitrogen status in wheat cultivars
Comparison of active and passive spectral sensors in discriminating biomass parameters and nitrogen status in wheat cultivars
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DOI：
10.1016/j.fcr.2011.06.007
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发表时间：
2011-10-09
影响因子：
5.8
通讯作者：
Schmidhalter, Urs
中科院分区：
文献类型：
--
作者：
Erdle, Klaus;Mistele, Bodo;Schmidhalter, Urs
有几种传感器系统可用于作物管理的地面遥感。多种主动和被动传感器的植被指数在确定植物健康方面很少进行比较。这项工作描述了一项比较主动和被动传感系统识别农艺参数的能力的研究。一个双向被动辐射计（BDR）和三个主动传感器，包括麦田圈、GreenSeeker和一个主动闪光传感器（AFS），测试了它们评估六个破坏性确定作物参数的能力。在2年的时间里，7个小麦（Triticum aestivum L）品种的氮素供应从0到220公斤公顷（-1）不等。在3个发育阶段，记录作物反射率并计算传感器特异性指数，这些指数与氮水平和作物参数、鲜重、干重、干物质含量、干重/鲜重百分比、氮素含量、地上氮素吸收量和氮营养指数有关。基于可见光和近红外光谱范围内不同波长组合的大多数测试指数在与作物参数相关时显示出较高的r(2)值。但不同传感器对不同氮素水平对作物各参数影响的识别精度存在差异，且与生长季节和发育阶段存在交互作用。基于可见光和红光的指数，如NDVI、简单比值（R-780/R-670）及相关指数随着林分密度的增加而趋于饱和，这是由于光谱信号的敏感性降低。在破坏性评价的生物量参数中，与n相关的参数关系最好，r(2)值最高可达0.96。近红外指标R-760/R-730是反映小麦氮素状况最有效且暂时稳定的指标。该指数由BDR、Crop Circle和AFS发布。主动光谱遥感在时效性和光照条件方面更加灵活，但迄今为止，它受限于有限的指标。目前，双向无源传感器的广谱信息为作物或特定品种算法的未来发展提供了增强的选择。(C) 2011 Elsevier B.V.版权所有
Several sensor systems are available for ground-based remote sensing in crop management. Vegetation indices of multiple active and passive sensors have seldom been compared in determining plant health. This work describes a study comparing active and passive sensing systems in terms of their ability to recognize agronomic parameters. One bi-directional passive radiometer (BDR) and three active sensors, including the Crop Circle, GreenSeeker, and an active flash sensor (AFS), were tested for their ability to assess six destructively determined crop parameters. Over 2 years, seven wheat (Triticum aestivum L) cultivars were grown with nitrogen supplies varying from 0 to 220 kg ha(-1). At three developmental stages, the crop reflectance was recorded and sensor-specific indices were calculated and related to N levels and the crop parameters, fresh weight, dry weight, dry matter content, as percent of dry weight to fresh weight, N content, aboveground N uptake, and the nitrogen nutrition index. The majority of the tested indices, based on different combinations of wavelengths in the visible and near infrared spectral ranges, showed high r(2)-values when correlated with the crop parameters. However, the accuracy of discriminating the influence of varying N levels on various crop parameters differed between sensors and showed an interaction with growing seasons and developmental stage. Visible- and red light-based indices, such as the NDVI, simple ratio (R-780/R-670), and related indices tended to saturate with increasing crop stand density due to a decreased sensitivity of the spectral signal. Among the destructively assessed biomass parameters, the best relationships were found for N-related parameters, with r(2)-values of up to 0.96. The near infrared-based index R-760/R-730 was the most powerful and temporarily stable index indicating the N status of wheat. This index was delivered by the BDR, Crop Circle, and AFS. Active spectral remote sensing is more flexible in terms of timeliness and illumination conditions, but to date, it is bound to a limited number of indices. At present, the broad spectral information from bi-directional passive sensors offers enhanced options for the future development of crop- or cultivar-specific algorithms. (C) 2011 Elsevier B.V. All rights reserved.