大气中基于多面体阵元能量辐射源有噪无源定向模型及抗噪研究

The passive direction of the radiation sources has long been the hot topic in the aerospace and the military applications. Current researches mainly focus on the space spectral estimation and the optical imaging. The space spectral estimation has the difficulty of application and the system structure complication. The problem is the direction field of view in some parts in the optical imaging and it is valid to the optical radiation sources. By adopting the new method and the constructed passive direction model achieved in preliminary studies which direct to spatial radiation based on the array elements energy probed by sensors on the polyhedron. In this method, the character of noise sources in atmosphere is analyzed and the parameter relationship is established between the kind of noise sources and the variables in the direction model with no noise. By means of all kinds of ways, some noises combination passive direction is constructed in this research program. The algorithms such as least square in matrix equation are adopted for each noise sources, anti-noise methods are constructed based on matrix equation of direction with noise, by using spatial spectrum estimation thought which replaces the temporal data in time domain processing with spatial data, research anti-noise methods based on noise spectrum or statistical characteristics. Based on the research method and results of each noise sources, further explore the anti-noise method of passive direction with combination of noise sources. By measurements and evaluating, propose anti-noise method for the noise sources. This research program is design to establish the theoretical basis for the radiation sources model of passive direction with noise based on the array elements energy on the polyhedron, providing theoretical basis of application in noise and the reference method, push forward for the practical applications.

辐射源无源定向在军事、航天等领域一直是国内外研究热点，现有研究主要集中在空间谱估计和光学成像，空间谱估计尚存在实用化难题、系统结构复杂等不足，而光学成像存在定向视场不全、仅适用光辐射源的问题。本课题采用前期研究工作中提出的用多面体阵元探测得到的能量对空间辐射源无源定向的新方法，结合已建无源定向模型，分析大气中噪声源的特性，研究各噪声源对定向模型中变量的影响关系，并以此建立有噪无源定向模型。针对各噪声源，结合矩阵方程求解中最小二乘等算法，基于有噪无源定向矩阵方程建立抗噪方法，借鉴空间谱估计利用空域数据代替时域处理中时域数据的思路，探索利用噪声频谱或统计特征抑制抗噪的方法，基于各噪声源无源定向抗噪的研究方法和结果，进一步探索多噪组合无源定向抗噪方法。通过实测评估，给出各噪声的参考抗噪方法。本研究旨在为本课题定向方法的研究奠定理论基础，为其噪声环境的应用提供理论依据和参考方法，从而推进其实用化。

基于阵元能量的辐射源定向是辐射源目标无源探测的重要技术之一。然而，因其易受干扰，该技术的应用受到了严重的限制。为提高该技术的抗噪性能，我们分析了大气中各噪声源对辐射源定向的影响关系，为其建立了首个定向噪声模型。针对现有定向方法，我们先为它建立了描述定向噪声能量、定向矩阵（辐射源定向方程的系数矩阵）和辐射源的能量对定向误差的影响关系式；随后，找到了它的性能评估、性能优化和最优阵列的设计方法；最后，证明了该方法存在无法完全抑制常量定向噪声的性能限制。针对该限制，我们建立了一种用定向矩阵子矩阵定向辐射源的新方法，并由此找到了一种完全抑制常量定向噪声的实现方法。基于正棱锥侧面构成的阵列，我们首次在频域找到了一种定向辐射源的新方法，并建立了描述定向噪声频谱函数、正棱锥几何结构（正棱锥侧面与底面的夹角）、辐射源的能量和它的方位角或高度角对定向误差的影响关系式，解决了频域定向的性能评估问题。通过该关系式，我们分析了频域定向的噪声抑制性能。基于这些噪声抑制性能，我们发现了探测系统内部噪声的完全抑制方法，找到了用两个底面正交的正棱锥完全抑制系统噪声和常量定向噪声的方法，证明了均匀大气中单辐射源无偏定向的可实现性。通过外场试验，我们还发现频域定向与现有定向方法的定向性能相同。由于现有方法和频域定向方法的定向误差关系式中存在不同的误差影响因素，该发现为正棱锥阵列定向性能的改善提供了新的研究方向。