动态海面舰船尾迹雷达散射特性研究

发布时间：2018-01-06 22:15

  本文关键词：动态海面舰船尾迹雷达散射特性研究　出处：《西安电子科技大学》2016年博士论文　论文类型：学位论文

  更多相关文章： 动态海面 舰船尾迹 合成孔径雷达成像 Doppler谱 有限深水域

【摘要】：动态海面舰船尾迹雷达散射特性研究在海洋遥感和海上舰船目标识别等领域有十分重要的研究意义。本文对动态海面舰船尾迹雷达散射特性的相关领域展开了系统的研究,在无限深水域和有限深水域条件下,对海面及其与舰船尾迹复合模型进行了几何建模、电磁散射建模和Doppler谱特性分析。论文的主要工作和成果如下：1.基于散射贡献的面元化思想,提出了面元散射模型,适合计算任意海况条件下的二维海面后向电磁散射系数空间分布,并以此模型为基础,实现了二维线性海面及其与舰船Kelvin尾迹复合模型的合成孔径雷达(SAR)快速模拟仿真,分析了极化条件、船速、风速、船体结构、风向角等因素对成像结果的影响,为舰船Kelvin尾迹图像识别算法的训练提供丰富的模板。2.通过引入锥形波入射并使用小斜率近似(SSA)模型,首先,计算研究了二维动态海面的电磁散射系数和Doppler谱特性,分析了雷达入射频率,极化方式,入射角,风速,和风向角等雷达参数和海环境因素以及非线性作用对Doppler频移和展宽的影响,分析结果表明与线性海面相比,非线性海面与实际海面场景更加相符合,二阶小斜率近似(SSA-Ⅱ)模型在定量的基础上能够有效地反映不同极化和不同非线性作用下海面Doppler频移和谱展宽特性差异。然后,结合舰船内波尾迹的几何模型,在低海况情况下,分区域研究了海面与舰船内波尾迹复合模型的电磁散射特性,分析了非线性作用和尾迹叠加对散射系数的影响。3.结合流体动力学理论,有限深海谱和修正的CWM (Choppy Wave Model)非线性模型,对受风区影响的二维有限深海面进行了几何建模,比较了不同风区和水深条件下的几何模型统计特性差异。采用SSA-Ⅱ模型对受风区影响的二维动态有限深海面回波Doppler谱特性进行了研究,数值计算并分析了水深、风区和极化方式以及其他雷达参数和海环境参数对Doppler谱特性的影响,结果反映出在较大风区下的近岸水域浅水环境中,海洋水动力调制作用得到了极大地增强,而且上述水动力调制效应对不同散射机制的影响程度是不同的,对同极化时的影响比交叉极化更加明显。4.首先,基于薄船理论和有限深水域边界条件,对有限深舰船Kelvin尾迹进行了几何建模,讨论了水深Froude数对有限深舰船Kelvin尾迹波形图的影响。然后,结合面元散射模型对有限深Kelvin尾迹进行了SAR成像仿真,分析了水深和极化方式等雷达参数和海环境参数对成像效果的影响。最后,利用SSA-Ⅱ模型计算了二维有限海面及其与舰船Kelvin尾迹复合模型的电磁散射系数,分析了海水深度对复合模型电磁散射系数的影响,并研究了二维有限海面与舰胎Kelvin尾迹复合模型的Doppler谱特性。
[Abstract]:The research on the scattering characteristics of dynamic sea ship wake radar is of great significance in the field of ocean remote sensing and ship target recognition. The relevant fields of dynamic sea ship wake radar scattering characteristics are studied in this paper. The study of Unification. In the condition of infinite deep water and finite deep water, the geometric modeling of the sea surface and its composite model with ship wake is carried out. Electromagnetic scattering modeling and Doppler spectrum analysis. The main work and results are as follows: 1. Based on the theory of scattering contribution, a plane scattering model is proposed. It is suitable to calculate the spatial distribution of backward electromagnetic scattering coefficients of two-dimensional sea surface under arbitrary sea conditions, and the model is based on this model. The fast simulation of synthetic Aperture Radar (SAR) based on two-dimensional linear sea surface and its composite model with ship Kelvin wake is realized. The polarization conditions, ship speed, wind speed and hull structure are analyzed. The influence of wind direction and other factors on the imaging results provides a rich template for the training of ship Kelvin wake image recognition algorithm. 2. By introducing conical wave incidence and using small slope approximate SSAs) model. First, the electromagnetic scattering coefficient and Doppler spectrum characteristics of two-dimensional dynamic sea surface are calculated and studied. The incident frequency, polarization mode, incidence angle and wind speed of radar are analyzed. The effects of radar parameters such as wind direction angle, sea environment factors and nonlinear action on the Doppler frequency shift and broadening are analyzed. The results show that the radar parameters are compared with the linear sea surface. The nonlinear sea surface is more consistent with the actual sea surface scene. The second order small slope approximation (SSA- 鈪，

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