L-band Microwave Emission of the Biosphere (L-MEB) Model: Description and calibration against experimental data sets over crop fields

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• 作者：J.-P. Wigneron ; Y. Kerr ; P. Waldteufel ; K. Saleh ; M.-J. Escorihuela ; P. Richaume ; P. Ferrazzoli ; P. de Rosnay ; R. Gurney ; J.-C. Calvet ; et al.
• 关键词：Passive microwave ; SMOS ; Soil ; Vegetation ; Soil moisture ; Modelling ; Inversion ; Algorithm ; L-MEB
• 刊名：Remote Sensing of Environment
• 出版年：2007
• 出版时间：30 April 2007
• 年：2007
• 卷：107
• 期：4
• 页码：639-655
• 全文大小：626 K

文摘

In the near future, the SMOS (Soil Moisture and Ocean Salinity) mission will provide global maps of surface soil moisture (SM). The SMOS baseline payload is an L-band (1.4 GHz) two dimensional interferometric microwave radiometer which will provide multi-angular and dual-polarization observations. In the framework of the ground segment activities for the SMOS mission an operational SMOS Level 2 Soil Moisture algorithm was developed. The principle of the algorithm is to exploit multi-angular data in order to retrieve simultaneously several surface parameters including soil moisture and vegetation characteristics. The algorithm uses an iterative approach, minimizing a cost function computed from the differences between measured and modelled brightness temperature (T_B) data, for all available incidence angles.<p>In the algorithm, the selected forward model is the so-called L-MEB (L-band Microwave Emission of the Biosphere) model which was the result of an extensive review of the current knowledge of the microwave emission of various land covers. This model is a key element in the SMOS L2 algorithm and could be used in future assimilation studies. There is thus a strong need for a reference study, describing the model and its implementation. In order to address these needs a detailed description of soil and vegetation modelling in L-MEB is given in this study. In a second step, the use of L-MEB in soil moisture retrievals is evaluated for several experimental data sets over agricultural crops. Calibrations of the soil and vegetation L-MEB parameters are investigated for corn, soybean and wheat. Over the different experiments, very consistent results are obtained for each vegetation type in terms of calibration and soil moisture retrievals.