Simulating Multifrequency Ground-Based Radiometric Measurements at Dome C-Antarctica
Simulating Multifrequency Ground-Based Radiometric Measurements at Dome C-Antarctica
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DOI：
10.1109/jstars.2015.2427512
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发表时间：
2015-09-01
影响因子：
5.5
通讯作者：
Jezek, Kenneth C.
中科院分区：
文献类型：
--
作者：
Brogioni, Marco;Macelloni, Giovanni;Jezek, Kenneth C.
由于有了新的星载辐射计，研究界最近对在低微波频率下研究南极洲产生了兴趣。对东南极高原的Dome C区域给予了特别关注，该区域被欧洲航天局（欧空局）选为土壤湿度和海洋盐度使命的校准和验证试验场。为了支持这一使命，并更好地描述现场的特点，进行了几次地面和空中活动。在DOMEX实验期间，对Dome C地基辐射计收集的微波测量数据进行分析，结果表明，即使在低频，冰盖参数剖面对微波发射也有重大影响。为了评估这一观察结果，在具有相干势和冰盖几何参数分布的准晶体近似下，使用多层致密介质辐射传输理论进行了微波发射的理论分析（即，温度、密度、分层和粒度）。电磁模型用于拟合在Dome C收集的C波段和L波段微波观测的角分布。分析确定雪密度垂直剖面的变化是确定L波段和C波段雪发射微波特征的主要因素。次要作用是由雪粒半径轮廓，明显影响C波段。
Recent interest by the research community in investigating Antarctica at low microwave frequency is stimulated by the availability of new satellite-borne radiometers. Special attention has been paid to the Dome C region of the East Antarctic Plateau, which was selected by the European Space Agency (ESA) as a calibration and validation test site for the soil moisture and ocean salinity (SMOS) mission. In order to support this mission and better characterize the site, several surface and airborne campaigns were conducted. Analysis of microwave measurements collected by ground-based radiometers at Dome C during the DOMEX experiments reveals that ice-sheet parameter-profiles have a significant impact on the microwave emission even at low frequencies. In order to assess this observation, a theoretical analysis of microwave emission was carried out using the multilayer dense medium radiative transfer theory under the quasi-crystalline approximation with coherent potentials and ice-sheet geophysical-parameter profiles (i.e., temperature, density, layering, and grain size) collected in the Dome C area. The electromagnetic model was used to fit the angular distribution of microwave observations collected at C-and L-bands at Dome C. The analysis identifies the variability in the snow density vertical profile as a major factor in determining the microwave signature of the snow emission at both L-and C-bands. A secondary role is played by the snow grain radius profile that appreciably influences C-band.