CAREER: Surface Scattering Effects in Mine Detection and Remote Sensing Systems

9701678约翰逊鉴于地雷对平民构成的风险，探测和识别埋在地下的地雷是一个重要问题，而从地面散布的地雷在目前正在调查的探地雷达技术中发挥着重要作用。地面散射在使用微波传感器遥感土壤水分方面也很重要，并会严重影响从卫星或飞机测量获得的土壤水分估计的准确性。然而，土壤表面散射对雷达测量的贡献仍未得到很好的了解，目前只有经验模型可用于预测，这些模型几乎不能深入了解减少表面杂波影响的方法。地表散射的解析近似模型也得到了发展，但基本的近似模型往往不适用于土壤表面，而且这些模型需要指定地表空间频谱，这是很难测量的，并且可获得的信息很少。在这个项目中，将通过分析、数值和实验技术对地面散射进行详细的研究，从而对重要的物理过程有新的见解。俄亥俄州立大学的超宽带探地雷达系统将用于在各种条件下测量电子科学实验室(ESL)室内靶场的表面散射，测量表面高度分布以确保其准确表征。将测量数据与测量的精确剖面的数值模型预测进行比较，使这项工作有别于以前对地面散射的纯经验研究，并能够确凿地确定分布表面与离散和/或体积散射的显著程度。基于这一改进的理解，将与现有分析模型进行比较，新的分析模型既包括表面效应，也包括研究产生的离散或体积散射效应。将对各种室外地表剖面进行进一步测量，并将研究减少地面杂波对探地雷达和土壤湿度遥感系统的影响的方法。***

9701678 Johnson The detection and identification of buried mines is an important problem given the risk land mines pose to civilian populations, and scattering from the surface of the ground plays a significant role in the ground penetrating radar technologies currently under investigation. Ground surface scattering is also important in the remote sensing of soil moisture with microwave sensors, and can strongly influence the accuracy of soil moisture estimates obtained from satellite or aircraft measurements. However, the contribution of soil surface scattering to radar measurements is still not well understood, and only empirical models, which allow little insight into methods for reducing surface clutter effects, are currently available for predictions. Analytical approximate models for ground surface scattering have also been developed, but the underlying approximations often are not valid for soil surfaces, and the models require specification of a surface spatial frequency spectrum, which is difficult to measure and for which little information is available. In this project, detailed studies of ground surface scattering which allow new insight into the important physical processes will be performed through analytical, numerical, and experimental techniques. The Ohio State ultra-wideband ground penetrating radar system will be used to measure surface scattering at the ElectroScience Laboratory (ESL) indoor range under a variety of conditions, with surface height profiles measured to insure their accurate characterization. A comparison of measured data with numerical model predictions for the exact profiles measured distinguishes this work from previous purely empirical studies of ground surface scattering, and enables conclusive determinations of the extent to which distributed surface versus discrete and/or volume scattering is significant. Comparisons with existing analytical models will be performed based on this improved understanding, with a new analytical model which inc ludes both surface and discrete or volume scattering effects resulting from the study. Further measurements will be done on a variety of outdoor surface profiles, and methods for reducing surface clutter effects on ground penetrating radar and soil moisture remote sensing systems will be investigated. ***