本文關(guān)鍵詞：動態(tài)海面艦船尾跡雷達(dá)散射特性研究　出處：《西安電子科技大學(xué)》2016年博士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 動態(tài)海面 艦船尾跡 合成孔徑雷達(dá)成像 Doppler譜 有限深水域

【摘要】：動態(tài)海面艦船尾跡雷達(dá)散射特性研究在海洋遙感和海上艦船目標(biāo)識別等領(lǐng)域有十分重要的研究意義。本文對動態(tài)海面艦船尾跡雷達(dá)散射特性的相關(guān)領(lǐng)域展開了系統(tǒng)的研究,在無限深水域和有限深水域條件下,對海面及其與艦船尾跡復(fù)合模型進行了幾何建模、電磁散射建模和Doppler譜特性分析。論文的主要工作和成果如下：1.基于散射貢獻(xiàn)的面元化思想,提出了面元散射模型,適合計算任意海況條件下的二維海面后向電磁散射系數(shù)空間分布,并以此模型為基礎(chǔ),實現(xiàn)了二維線性海面及其與艦船Kelvin尾跡復(fù)合模型的合成孔徑雷達(dá)(SAR)快速模擬仿真,分析了極化條件、船速、風(fēng)速、船體結(jié)構(gòu)、風(fēng)向角等因素對成像結(jié)果的影響,為艦船Kelvin尾跡圖像識別算法的訓(xùn)練提供豐富的模板。2.通過引入錐形波入射并使用小斜率近似(SSA)模型,首先,計算研究了二維動態(tài)海面的電磁散射系數(shù)和Doppler譜特性,分析了雷達(dá)入射頻率,極化方式,入射角,風(fēng)速,和風(fēng)向角等雷達(dá)參數(shù)和海環(huán)境因素以及非線性作用對Doppler頻移和展寬的影響,分析結(jié)果表明與線性海面相比,非線性海面與實際海面場景更加相符合,二階小斜率近似(SSA-Ⅱ)模型在定量的基礎(chǔ)上能夠有效地反映不同極化和不同非線性作用下海面Doppler頻移和譜展寬特性差異。然后,結(jié)合艦船內(nèi)波尾跡的幾何模型,在低海況情況下,分區(qū)域研究了海面與艦船內(nèi)波尾跡復(fù)合模型的電磁散射特性,分析了非線性作用和尾跡疊加對散射系數(shù)的影響。3.結(jié)合流體動力學(xué)理論,有限深海譜和修正的CWM (Choppy Wave Model)非線性模型,對受風(fēng)區(qū)影響的二維有限深海面進行了幾何建模,比較了不同風(fēng)區(qū)和水深條件下的幾何模型統(tǒng)計特性差異。采用SSA-Ⅱ模型對受風(fēng)區(qū)影響的二維動態(tài)有限深海面回波Doppler譜特性進行了研究,數(shù)值計算并分析了水深、風(fēng)區(qū)和極化方式以及其他雷達(dá)參數(shù)和海環(huán)境參數(shù)對Doppler譜特性的影響,結(jié)果反映出在較大風(fēng)區(qū)下的近岸水域淺水環(huán)境中,海洋水動力調(diào)制作用得到了極大地增強,而且上述水動力調(diào)制效應(yīng)對不同散射機制的影響程度是不同的,對同極化時的影響比交叉極化更加明顯。4.首先,基于薄船理論和有限深水域邊界條件,對有限深艦船Kelvin尾跡進行了幾何建模,討論了水深Froude數(shù)對有限深艦船Kelvin尾跡波形圖的影響。然后,結(jié)合面元散射模型對有限深Kelvin尾跡進行了SAR成像仿真,分析了水深和極化方式等雷達(dá)參數(shù)和海環(huán)境參數(shù)對成像效果的影響。最后,利用SSA-Ⅱ模型計算了二維有限海面及其與艦船Kelvin尾跡復(fù)合模型的電磁散射系數(shù),分析了海水深度對復(fù)合模型電磁散射系數(shù)的影響,并研究了二維有限海面與艦胎Kelvin尾跡復(fù)合模型的Doppler譜特性。
[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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