MICROWAVE DIELECTRIC BEHAVIOR OF WET SOIL .2. DIELECTRIC MIXING MODELS
MICROWAVE DIELECTRIC BEHAVIOR OF WET SOIL .2. DIELECTRIC MIXING MODELS
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DOI：
10.1109/tgrs.1985.289498
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发表时间：
1985-01-01
影响因子：
8.2
通讯作者：
ELRAYES, MA
中科院分区：
文献类型：
--
作者：
DOBSON, MC;ULABY, FT;ELRAYES, MA
本文是第二次在一系列评估的微波介电性能的土壤-水混合物作为一个功能的含水量和土壤质地组成。第二部分利用第一部分[13]中提供的数据，为1.4至18 GHz区域开发适当的经验和理论介电混合模型。基于折射率的半经验混合模型，只需要很容易确定的土壤物理参数，如体积水分和土壤质地成分作为输入。此外，一个明确的理论模型占结合水的亲水性土壤颗粒表面附近的水化层的存在。四组分介电混合模型将土壤-水系统视为干燥土壤固体的宿主介质，所述干燥土壤固体包含随机分布和随机取向的结合水、散装水和空气的盘形夹杂物。散装水成分被认为是依赖于频率，温度和盐度。通过土壤物理模型将土壤溶液区分为1）结合组分和2）本体土壤溶液。每个模型的性能作为土壤湿度、土壤质地和频率的函数进行评估，使用频率在1.4和18 GHz之间的桑迪壤土到粉质粘土（如第I部分[13]所示）的五种土壤的介电测量值。的半经验混合模型产生一个很好的适合在4 GHz以上的频率的测量数据。在1.
This paper is the second in a series evaluating the microwave dielectric behavior of soil-water mixtures as a function of water content and soil textural composition. Part II draws upon the data presented in Part 1 [13] to develop appropriate empirical and theoretical dielectric mixing models for the 1.4-to 18-GHz region. A semiempirical mixing model based upon the index of refraction is presented, requiring only easily ascertained soil physical parameters such as volumetric moisture and soil textural composition as inputs. In addition, a theoretical model accounting explicitly for the presence of a hydration layer of bound water adjacent to hydrophilic soil particle surfaces is presented. A four-component dielectric mixing model treats the soil-water system as a host medium of dry soil solids containing randomly distributed and randomly oriented disc-shaped inclusions of bound water, bulk water, and air. The bulk water component is considered to be dependent upon frequency, temperature, and salinity. The soil solution is differentiated by means of a soil physical model into 1) a bound component and 2) a bulk soil solution. The performance of each model is evaluated as a function of soil moisture, soil texture, and frequency, using the dielectric measurements of five soils ranging from sandy loam to silty clay (as presented in Part I [13]) at frequencies between 1.4 and 18 GHz. The semiempirical mixing model yields an excellent fit to the measured data at frequencies above 4 GHz. At 1.