气溶胶粒和冰水两相粒子的散射特性.

气溶胶和冰水两相粒子的散射特性112347研究意义及现状气溶胶粒子组成Mie和Aden-KerKer理论特别之处与未尽工作56气溶胶粒子太赫兹波散射特性冰水两相粒子毫米波散射特性研究结论提纲21.研究目的和意义1.现代通信、导航、气象、定位等过程中，需要考虑大气散射的所带来的误差，其中云中冰晶和气溶胶是大气中最重要的散射来源，尤其近年来日益增多的雾霾天气、沙尘天气凸显了大气气溶胶散射特性研究的重要性。2.研究结果对对流层气象探测、对流层散射特性、医学生物体细胞监测有一定的参考价值。32.研究现状罗轶等微米镍粉在太赫兹波段的Mie散射特性研究2005200720112013周旺等微波传输中沙尘衰减的计算与仿真Hong.GetMicrowavescatteringpropertiesofsandparticles李丽芳近红外波段气溶胶的衰减特性研究42.研究现状太赫兹波段(30µm～3mm)现实意义毫米波段(1～10mm)35GHz94GHz140GHz220GHz5气溶胶的组成和分类1.沙尘性粒子2.海洋性粒子3.水溶性粒子4.烟煤5.火山灰6.75%硫酸液滴对流层（10-18km）平流层3.气溶胶粒子组成本文主要研究对流层的4种粒子和冰水两相粒子。64.Mie和Aden-KerKer理论7Aden理论给出冰水两相粒子复折射率的计算，仿真得出冰水两相粒子的散射特性。给出粒子的Mie理论extQscaQabsQbQ等散射参数，仿真得出海洋性、沙尘性等粒子散射特性。5.冰水两相粒子复折射率的计算81601802002202402602800123456x10-3temperature(K)complexrefractiveindex(imaginarypart)theimaginarypartofcomplexrefractiveindex(ice)35G94G140G220G1801902002102202302402502602701.761.7651.771.7751.781.785temperature(K)complexrefractiveindex(realpart)therealpartofcomplexrefractiveindex(ice)35G94G140G220G35GHz、94GHz、140GHz、220GHz纯冰粒子的复折射率受温度影响，当频率一定时，纯冰晶的复折射率实部与温度成线性关系，虚部随着温度的升高而增大，且增加幅度也是越来越大。虚部实部冰水两相粒子复折射率的计算9上图给出35GHz、94GHz、140GHz、220GHz纯冰粒子的复折射率受频率的影响，当温度一定时，纯冰粒子的复折射率的虚部与频率成线性关系。1601802002202402602801.7551.761.7651.771.7751.781.7851.79Frequency(GHz)complexrefractiveindex(realpart)therealpartofcomplexrefractiveindex(ice)173k193k213k253k16018020022024026028011.522.533.544.55x10-3Frequency(GHz)complexrefractiveindex(imagpart)theimaginarypartofcomplexrefractiveindex(ice)173k193k213k253k虚部实部气溶胶粒子太赫兹波散射特性102.5e-0095e-0093021060240902701203001503301800m=1.9-0.5i,x=0.052.5e-0095e-0093021060240902701203001503301800m=1.92-0.4i,x=0.05沙尘性粒子水溶性粒子2e-0094e-0093021060240902701203001503301800m=1.597-0.38i,x=0.055e-0091e-0083021060240902701203001503301800m=2.63-0.97i,x=0.05烟煤海洋性粒子35μm时，小尺度粒子散射。粒子散射强度依次为，烟煤、沙尘性、水溶性、海洋性粒子。且前向散射和后向散射强度相等，符合瑞利散射。上半圆：散射强度垂直分量下半圆：散射强度平行分量气溶胶粒子太赫兹波散射特性1135μm时，大尺度粒子散射。散射强度随散射角的分布越来越复杂，前向散射散射强度加强，后向散射减弱。符合Mie散射规律。2004003021060240902701203001503301800m=1.9-0.5i,x=42004003021060240902701203001503301800m=1.92-0.4i,x=4沙尘性粒子水溶性粒子50010003021060240902701203001503301800m=1.597-0.38i,x=41002003021060240902701203001503301800m=2.63-0.97i,x=4海洋性粒子烟煤上半圆：散射强度垂直分量下半圆：散射强度平行分量40μm时四种粒子的散射系数1200.20.40.60.811.21.41.61.82-10-505101520xMieEfficienciesm=2.1-0.6i00.20.40.60.811.21.41.61.82-15-10-50510152025xm=1.86-0.5iQextQscaQabsQbcostetaQb/QscaQextQscaQabsQbcostetaQb/QscaDustparticles40μmWatersolubleparticles40μm13Marineparticles40μmBituminouscoal40μm00.20.40.60.811.21.41.61.82-10-505101520m=1.58-0.561ixMieEfficiencies00.20.40.60.811.21.41.61.82-10-505101520m=2.69-1ixQextQscaQabsQbcostetaQb/QscaQextQscaQabsQbcostetaQb/Qsca沙尘性粒子和水溶性粒子后向散射系数峰值强于海洋性粒子和烟煤，沙尘性粒子和海洋性粒子吸收系数比水溶性和烟煤变化要大；烟煤的衰减系数明显强于其他三种气溶胶粒子。波长对粒子散射系数的影响14Dustparticles30μmDustparticles35μm波长30μm时沙尘性粒子后向散射系数峰值明显高于波长35μm的峰值，波长30μm时沙尘性粒子吸收系数随尺度参数变化范围较大。00.20.40.60.811.21.41.61.82-30-20-1001020304050xMieEfficienciesm=1.8-0.42iQextQscaQabsQbcostetaQb/Qsca00.20.40.60.811.21.41.61.82-15-10-5051015202530xMieEfficienciesm=1.9-0.5iQextQscaQabsQbcostetaQb/Qsca水溶性粒子的散射相位函数1500.511.522.5310-210-1100101102103ScatteringAnglePhaseFunction单个水溶性粒子散射相位函数与theta关系x=400.511.522.5310-210-1100101102103ScatteringAnglePhaseFunction单个水溶性粒子散射相位函数与theta关系x=1230μm时，随着尺度参数的增加,散射相函数曲线极值点越来越多,这是由于随着尺度参数的增加,散射相函数随散射角变化剧烈。6.冰水两相粒子毫米波段散射特性160.00020.00040.00063021060240902701203001503301800Mieangularscattering:fghz=35GHz,TK=273kScatteringfunction510153021060240902701203001503301800Mieangularscattering:fghz=94GHz,TK=273kScatteringfunction35GHz94GHz17140GHz220GHz20040060080010003021060240902701203001503301800Mieangularscattering:fghz=140GHz,TK=273kScatteringfunction500001000001500003021060240902701203001503301800Mieangularscattering:fghz=220GHz,TK=273kScatteringfunction随着频率的升高，粒子的散射能量越来越强且越来越集中于前向。气泡对纯冰球散射的影响1835GHz94GHz0.00020.00040.00063021060240902701203001503301800Mieangularscattering:fghz=35GHz,TK=273kScatteringfunction纯冰占空比1%占空比5%510153021060240902701203001503301800Mieangularscattering:fghz=94GHz,TK=273kScatteringfunction纯冰占空比1%占空比5%19140GHz220GHz粒子的散射能量越来越集中于前向，纯冰中的气泡的占空比越高导致各个方向上的散射截面越小，若忽略冰晶中的空气的影响，则会导致RCS计算大于实际值。20040060080010003021060240902701203001503301800Mieangularscattering:fghz=140GHz,TK=273kScatteringfunction纯冰占空比1%占空比5%500001000001500003021060240902701203001503301800Mieangularscattering:fghz=220GHz,TK=273kScatteringfunction纯冰占空比1%占空比5%水膜冰球散射参数随内外球半径比的变化关系2034GHz、94GHz时水膜冰球的衰减系数随着内外球半径比的增大是一直在增大，这说明随着内冰球半径的增大水膜冰球对电磁波的衰减也是增强的。00.10.20.30.40.50.60.70.80.9100.511.522.533.5a/bMieEfficienciesofcoatedsphere,y=1,m1=4.12611+2.44894i,m2=1.78561+0.000852558iQextQscaQabsQbcosteta34GHz00.10.20.30.40.50.60.70.80.9100.511.522.533.5a/bMieEfficienciesofcoatedsphere,y=1,m1=2.91217+1.44194i,m2=1.78561+0.00234684iQextQscaQabsQbcosteta94GHz水膜气泡散射参数随内外球半径比的变化关系21水膜气泡的衰减系数随着内气泡的增大先是不变后迅速衰减，内外球半径比为0.9时为各项参数的一个拐点。00.10.20.30.40.50.60.70.80.9100.511.522.53a/bMieEfficienciesofcoatedsphere,y=5,m1=1+0i,m2=4.12611+2.44894iQextQscaQabsQbcosteta34GHz00.10.20.30.40.50.60.70.80.9100.511.522.53a/bMieEfficienciesofcoatedsphere,y=5,m1=1+0i,m2=2.91217+1.44194iQe