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

为了开发利用近期卫星观测数据估算地表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无源传感器，它观测频率和极化组合不同的多个微波，它也是定于2000年发射的ADEOS-II上安装的AMSR上的一个。从五个选定的频率AMSR的观测数据，提取两个不同的积雪参数的算法。利用北海道地区的积雪参数，对算法的有效性进行了研究。研究结果表明，该算法是有效的，可以测量大面积积雪的厚度和粒径.提出了利用合成孔径雷达观测得到的多幅微波图像中包含的相位信息估计积雪参数的方法。对L波段干涉SAP（干涉合成孔径雷达）观测层状结构积雪时所获得的数据进行了模拟和分析。分析结果表明，雪层边界的散射效应小于地面的散射效应，这是有效的，利用L波段的频率进行干涉合成孔径雷达可以很好地测量积雪深度。此外，还阐明了利用干涉条纹可视化积雪深度空间分布的可能性。

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.