The research of the remote sensing of the snowpack using multiple microwaves

为了发展从不久的将来获得的卫星观测数据估算地球表面积雪物理参数的技术，开展了以下两项研究。多频微波辐射计是一种被动传感器，它观测频率和极化组合不同的多个微波，也是安装在ADEOS-11上的AMSR上的被动传感器，计划于2000年发射。根据AMSR选择的5个频率的观测数据，提出了提取两种不同积雪参数的算法。利用北海道地区普遍观测到的积雪参数，研究了该算法的有效性。研究结果表明，该算法是有效的，可以测量大面积积雪的深度和粒度。针对合成孔径雷达观测得到的多幅微波图像，提出了一种利用相位信息估计积雪参数的方法。对L波段干涉合成孔径雷达观测层状结构积雪所获得的数据进行了模拟分析。分析结果表明，雪层边界的散射效应小于地面的散射效应，说明利用L波段的频率进行干涉合成孔径雷达测量积雪深度具有较高的精度。此外，利用干涉条纹可视化积雪深度的空间分布也是可能的。

Following two researches were carried out in order to develop the technique which estimates the physical parameters of the snowpack on the earth surface from satellite observation data acquired in the close future.1. The multifrequency microwave radiometer is passive sensor, which observes the multiple microwaves in which the combination of frequency and polarization differs, and it is also the one on AMSR mounted at the ADEOS-Il that the launch has been scheduled in 2000. From the data observed at five selected frequencies of AMSR, the algorithm for extracting two different snowpack parameters was developed. Using snowpack parameters observed in the Hokkaido district generally, the effectiveness of developed algorithm was investigated. The result of the investigation showed being effective so that the algorithm may measure depth and grain size of the snowpack of wide area.2. The technique that estimated the snowpack parameter using the phase information, which is included for multiple microwave images obtained by the observation of synthetic-aperture radar, was developed. Simulation and analysis of the data to be obtained when the L band interferometric SAP (InSAR) observed the snowpack with the layered structure were carried out. The result of the analysis showed that the scattering effect from the boundary in the snow layer was smaller than scattering effect from the ground, and that it is effective so that InSAR using the frequency of the L band may measure the depth of the snowpack at the good accuracy. In addition, that to visualize the spatial distribution of the depth of the snowpack using the interference fringe was possible also clarified.