Land surface temperature from Ka band (37 GHz) passive microwave observations
Land surface temperature from Ka band (37 GHz) passive microwave observations
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DOI：
10.1029/2008jd010257
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发表时间：
2009-02-25
影响因子：
4.4
通讯作者：
Dolman, A. J.
中科院分区：
文献类型：
--
作者：
Holmes, T. R. H.;De Jeu, R. A. M.;Dolman, A. J.
介绍了一种替代热红外卫星传感器测量地表温度的方法。37 GHz的垂直极化亮度温度被用来推导T-s，因为它被认为是最合适的微波频率的温度反演。该通道平衡了对土壤表面特性的敏感性降低与相对较高的大气穿透率。结果表明，一个简单的线性关系，准确的值Ts可以从这个频率，在1 K内的理论偏差为70%的植被覆盖的土地面积的地球仪。贫瘠、植被稀疏和开阔的灌木丛不能用这种单通道方法准确描述，因为可变的表面条件变得很重要。反演地表温度的精度，预计将优于2.5 K的森林和3.5 K的低植被。该方法可用于补充现有的红外温度产品，特别是在多云条件下。目前有几个微波辐射计在轨道上，这种方法可以用来观察昼夜温度循环，具有惊人的准确性。
An alternative to thermal infrared satellite sensors for measuring land surface temperature (T-s) is presented. The 37 GHz vertical polarized brightness temperature is used to derive T-s because it is considered the most appropriate microwave frequency for temperature retrieval. This channel balances a reduced sensitivity to soil surface characteristics with a relatively high atmospheric transmissivity. It is shown that with a simple linear relationship, accurate values for Ts can be obtained from this frequency, with a theoretical bias of within 1 K for 70% of vegetated land areas of the globe. Barren, sparsely vegetated, and open shrublands cannot be accurately described with this single channel approach because variable surface conditions become important. The precision of the retrieved land surface temperature is expected to be better than 2.5 K for forests and 3.5 K for low vegetation. This method can be used to complement existing infrared derived temperature products, especially during clouded conditions. With several microwave radiometers currently in orbit, this method can be used to observe the diurnal temperature cycles with surprising accuracy.