中小尺度地基GPS精细化反演土壤湿度研究

项目名称： 中小尺度地基GPS精细化反演土壤湿度研究

项目编号： No.41204021

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 地球物理学和空间物理学

项目作者： 桑文刚

作者单位： 山东建筑大学

项目金额： 25万元

中文摘要： 不同时空分辨率的土壤湿度观测资料对研究全球气候变化，提高短时天气预报的准确性以及开展洪涝、干旱等灾害的监测与治理都具有重要意义。为弥补卫星遥感土壤湿度时空分辨率的不足以及验证遥感数据与反演算法的有效性，本项目首先从影响GPS信号波动的多种因子在不同类型观测值中的相关特性与频谱特征入手，基于分形理论与小波互相关分析法，研究从SNR信号中精细提取土壤湿度成分的算法；其次利用GPS反射信号中植被生长成分，探索基于谱分析法绘制2维植被分布图的方法，并在时空同步机制下研究去除或减弱植被覆盖对反演精度影响的理论与算法，使常规测量型GPS在单站单天线模式下反演土壤湿度成为现实；最后利用地统计学方法分析反演资料，以揭示中小尺度区域土壤湿度的时空变异规律，为地基GPS反演数据与卫星遥感影像或数据的时间同步与几何配准奠定基础，从而实现对大尺度监测模式的数据及反演算法进行验证与评价。

中文关键词： 全球气候变化；土壤湿度；GPS-R；多路径；分形

英文摘要： Measurements of soil moisture at various temporal and spatial scales are important for studies of global climate change, weather forecasting, as well as flood or drought prediction and management. While satellite missions have been planned to measure soil moisture at global scales, these missions also need ground-based soil moisture data with high temporal-spatial resolution to validate their observations and retrieval algorithms. Therefore, the main objective of this project is to develop refinement methodology and strategies for soil moisture retrieval using ground-based GPS for meso-micro scale applications. Firstly, the influence, caused by various environment factors, may be different in quantities for different observations or their linear combinations of GPS. However, they might have significant correlation and similar spectrum characteristics. We plan to design a special filter to separate soil moisture component from signal-to-noise data with high accuracy and reliability. Secondly, we will develop a methodology based on spectrum analysis to obtain the two dimensional vegetation distribution map using the GPS reflected signal and then a spatiotemporal synchronization approach will be proposed to remove or reduce the influence about vegetation growth. It will provide a novel way to monitor soil moisture

英文关键词： Global climate change；Soil moisture；GPS-R；Multipath；Fractal