Algorithm development to detect moisture, thaw/freeze condition by using radar.

本研究的目的是为了阐明以下问题：1)了解不同水分条件和融冻条件下多年冻土的雷达反射机制；2)开发一个算法来估计多年冻土地区的水分和探测融化/冻结条件；3)制作西伯利亚地区的融化/冻结地图，并讨论其对当地生活的影响。1)为了解决这些问题，提出了冻土区的两层模型，该模型很好地解释了PALSAR/全极化数据(文献(3))。解冻条件通过后向散射系数进行分类(文献(7))。为了解决问题2)，提出了一种估计土壤湿度的算法(文件(7))，基于1中的结果。为了解决问题3)，在俄罗斯勒纳河周围用PALSAR全极化模式制作了冻结/融化图。地图显示，2007年导致马尔卡大冰堵的可能原因之一是地面迅速融化。

The purpose of this study is to clarify the following issues.1) Understanding the radar reflection mechanism from permafrost with different moisture condition, and with thaw/freeze condition.2) Develop an algorithm for estimating moisture and detect thaw/freeze condition in the permafrost area.3) Produce the thaw/freeze map in Siberia and discuss the effect for the local life.To address issues 1), two layer model was suggested for a permafrost area, and it is shown that the model well explains the PALSAR/full polarimetry data (Paper (3)). Thaw/freeze condition was classified by the backscattering coefficient (Paper (7)). To address issues 2), an algorithm to estimate the soil moisture was suggested (Paper (7)), based on the results in 1). To address issue 3), freeze/thaw map was produced around the Lena River in Russia from PALSAR full polarimetry mode. The map indicates that one of the possible reasons for inducing the large ice jam in Markha in 2007 was rapid ground thawing.