赵敏,栾宇哲,朱羽晞,等. 不确定参数目标电磁散射特性计算及评估[J]. 电波科学学报,xxxx,x(x): x-xx. DOI: 10.12265/j.cjors.2023266
      引用本文: 赵敏,栾宇哲,朱羽晞,等. 不确定参数目标电磁散射特性计算及评估[J]. 电波科学学报,xxxx,x(x): x-xx. DOI: 10.12265/j.cjors.2023266
      ZHAO M, LUAN Y Z, ZHU Y X, et al. Calculation and evaluation of electromagnetic scattering characteristics of targets with uncertain parameters[J]. Chinese journal of radio science,xxxx,x(x): x-xx. (in Chinese). DOI: 10.12265/j.cjors.2023266
      Citation: ZHAO M, LUAN Y Z, ZHU Y X, et al. Calculation and evaluation of electromagnetic scattering characteristics of targets with uncertain parameters[J]. Chinese journal of radio science,xxxx,x(x): x-xx. (in Chinese). DOI: 10.12265/j.cjors.2023266

      不确定参数目标电磁散射特性计算及评估

      Calculation and evaluation of electromagnetic scattering characteristics of targets with uncertain parameters

      • 摘要: 针对非合作目标信息不完备,以及由于制作工艺、环境因素、人为因素等原因导致的目标几何外形、材料属性等不确定性现状,首先,介绍了基于泰勒级数展开的不确定性目标电磁散射特性分析方法。运用非均匀有理B样条(nonuniform rational B-spline surface,NURBS)建模方法,实现任意形状目标的外形构建;运用目标外形参数、介质参数提取技术,建立目标几何外形、介电参数与矩量法电磁积分方程的函数关系,由此计算出由外形、介质变化产生的电流变化量,进而分析几何外形、介质引入随机变量时,金属/介质/混合目标的电磁散射特性。其次,提出了一种基于渐进波形估计(asymptotic waveform evaluation, AWE)技术的高维不确定性目标电磁散射特性分析方法。通过伪谱法求解各阶导数,相较于公式求导能够节省大量推导和计算时间;运用Padé近似计算目标改变之后的最终电流,相较于基于泰勒级数展开的求解方法,能够准确计算更大的随机扰动量相较于蒙特卡洛(Monte Carlo, MC)方法,提高了计算效率,且仿真与实测结果吻合一致。最后,利用BP神经网络实现对不确定性目标散射特性的置信度和不确定度的智能化计算,证明了本文方法不仅能够有准确有效地分析非合作目标的高维不确定性问题,而且大幅提高了计算效率。

         

        Abstract: Aimed at the current situation of incomplete information on non-cooperative targets and uncertainties in target geometry and material properties due to manufacturing processes, environmental factors, human factors, etc., the method of analyzing the electromagnetic scattering characteristics of uncertain targets based on Taylor series expansion is presented. The nonuniform rational B-spline surface(NURBS) modelling technology is used to construct arbitrary shaped targets. The target shape parameter and dielectric parameter extraction techniques are used to establish the functional relationship between the target geometric shape/dielectric parameter and the electromagnetic integral equation of the method of moments. From this, the amount of current change due to changes in shape and medium is calculated, and then the electromagnetic scattering characteristics of metal/medium/mixed targets are analyzed when random variables are introduced into the geometric shape and medium. Secondly, this paper proposes a technique for analyzing the electromagnetic scattering characteristics of uncertain high-dimensional targets based on the asymptotic waveform evaluation(AWE) method. It extends the asymptotic waveform estimation technique to encompass the analysis of target shape and dielectric constant uncertainty. Calculating the derivatives of each order using the pseudo-spectral method can significantly reduce derivation and computation time, as compared to deriving formulae. The Padé approximation is employed by this technique to determine the final current following a change in the target. Additionally, it has the ability to precisely compute a greater degree of random perturbation in contrast to methods relying on Taylor series expansions. Compared to the Monte Carlo (MC) method, the approach presented in this paper greatly enhances the overall computational efficiency. Simulated and measured results are in agreement. Finally, a backpropagation neural network is utilized to achieve intelligent calculation of confidence and uncertainty regarding the scattering characteristics of uncertain targets. It is demonstrated that the proposed method provides an accurate and effective analysis of the high-dimensional uncertainty problem pertaining to non-cooperative targets, thereby substantially enhancing computational efficiency.

         

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