Development of analysis methods of the microwave data measured by satellites for the long-term dynamic phase clarification of the snowcover in polar region

针对利用各种卫星微波传感器监测极地积雪长期动态相位的问题，主要进行了以下三方面的研究：1.积雪参数的估计算法，将在卫星传感器地表分辨率范围内具有均匀结构的积雪模型用于替代自然积雪。然后，考虑到系统与传感器使用性能的差异，分析了积雪参数对系统性能的影响，（深度，层数，粒度，密度和含水量）提出了一种由模型的发射率或复后向散射系数来确定模型结构的算法提出了从MSR/MOS-1和AMSR/ADEOS-2等星载微波辐射计测量的亮温中提取积雪比辐射率的分析方法。利用该方法对日本北海道观测的MSR资料进行分析，得到了与地面观测雪特征具有良好对应关系的结果。该方法也适用于极区观测MSR数据，没有获得地面真值数据，验证了利用SAR数据获取积雪深度和积雪粒径参数的可行性（合成孔径雷达）本文介绍了由多轨道观测的复散射系数估计积雪深度和密度参数的分析方法。研制了搭载L波段合成孔径雷达的JERS-1和ALOS等卫星。在北海道，利用搭载在飞机上的L波段Pi-SAR进行了验证该分析方法有效性的实验，并报告了获取数据的分析结果。

Three development described in the following was mainly carried out for monitoring the long-term dynamic phase of the snowcover in polar region using various satellites microwave sensor.1.Estimation algorithm of the snowpack parameters.The snowpack model with the uniform structure in the range of the earth surface resolution of the satellite sensor was used in the alternative of the natural snowcover. Then, by taking the difference between system and performance of utilizing sensor into consideration, the effect of the snowpack parameters (depth, number of the layer, grain size, density and water content) which constitutes the model was simulated and the algorithm which reversely decided the model structure from emissivity or complex backscattering coefficient on the model was developed.2.Analysis method of the data measured by microwave radiometer.The analysis method which extracts the emissivity of snowpack from the brightness temperature measured by satellite installation microwave radiometer such as MSR/MOS-1 and AMSR/ADEOS-2, was developed. Using this method, when the MSR data obtained by the observation of Hokkaido, Japan was analyzed, the result of good correspondence in snow characteristics observed in the ground was obtained. This method was also applied to polar region observation MSR data that ground truth data had not been obtained, and it was verified that to obtain the snowpack parameters of depth and grain size is possible.3.Analysis method of the data measured by SAR (synthetic aperture radar).The analysis method which estimated the snowpack parameters of depth and density from the backscattering coefficient of complex number measured from multiple orbits of the satellite such as JERS-1 and ALOS, mounted the L-band SAR, was developed. The experiment for the verification on the effectiveness of this analysis method was carried out in Hokkaido, using Pi-SAR (L-band) mounted on the aircraft, and the analytical result of acquiring data was reported.