From the actual perspective of working principle of localizer beacon subsystem of Instrument Landing System (ILS), consideration of the distance information from localizer antenna to field monitor antenna and wide ape...From the actual perspective of working principle of localizer beacon subsystem of Instrument Landing System (ILS), consideration of the distance information from localizer antenna to field monitor antenna and wide aperture effect of localizer antenna, broke through the limitation of signals synthesized only far-field (FF), established the near-field (NF) model. The three-dimensional mathematical model of localizer beacon was designed, and the signals at both near-field and far-field were analyzed qualitatively. At the environment of Antenna Fault as well as Antenna Distribution Unit (ADU) phase shifter simulation, the characteristics of near-field and far-field were also compared. The simulation results showed that the model met the requirement of theory of localizer beacon, and the gap between two models was so evident, which resulted from the broken geometric symmetry in NF area. The model could provide valuable theoretical basis for performance evaluation and maintenance of the ILS, and meanwhile, provide reference for the further analysis of localizer beacon.展开更多
在电子对抗中,小功率干扰技术是近几年研究的焦点,本文研究了小功率干扰对仪表着陆系统(instrument landing system,ILS)性能的影响,为ILS干扰环境的效能评估提供参考。首先,推导了ILS的测量参数调制度差(difference of degree of modul...在电子对抗中,小功率干扰技术是近几年研究的焦点,本文研究了小功率干扰对仪表着陆系统(instrument landing system,ILS)性能的影响,为ILS干扰环境的效能评估提供参考。首先,推导了ILS的测量参数调制度差(difference of degree of modulation,DDM)受干扰影响的数学表达式;其次,以干扰源的功率、位置等关键参数为参变量,通过计算机仿真分析了在着陆引导区域内DDM产生的误差。理论分析与仿真结果表明,小功率干扰对ILS性能影响明显,必须采取相应的干扰抑制技术,以改善系统的引导性能。展开更多
文摘From the actual perspective of working principle of localizer beacon subsystem of Instrument Landing System (ILS), consideration of the distance information from localizer antenna to field monitor antenna and wide aperture effect of localizer antenna, broke through the limitation of signals synthesized only far-field (FF), established the near-field (NF) model. The three-dimensional mathematical model of localizer beacon was designed, and the signals at both near-field and far-field were analyzed qualitatively. At the environment of Antenna Fault as well as Antenna Distribution Unit (ADU) phase shifter simulation, the characteristics of near-field and far-field were also compared. The simulation results showed that the model met the requirement of theory of localizer beacon, and the gap between two models was so evident, which resulted from the broken geometric symmetry in NF area. The model could provide valuable theoretical basis for performance evaluation and maintenance of the ILS, and meanwhile, provide reference for the further analysis of localizer beacon.
文摘在电子对抗中,小功率干扰技术是近几年研究的焦点,本文研究了小功率干扰对仪表着陆系统(instrument landing system,ILS)性能的影响,为ILS干扰环境的效能评估提供参考。首先,推导了ILS的测量参数调制度差(difference of degree of modulation,DDM)受干扰影响的数学表达式;其次,以干扰源的功率、位置等关键参数为参变量,通过计算机仿真分析了在着陆引导区域内DDM产生的误差。理论分析与仿真结果表明,小功率干扰对ILS性能影响明显,必须采取相应的干扰抑制技术,以改善系统的引导性能。
文摘仪表着陆系统(instrument landing system,ILS)的下滑信标(glide slope,GS)辐射场由GS天线及其对称于地面的镜像天线辐射场形成,辐射场性能受GS天线附近场地影响很大。在GS保护区内,影响其辐射场性能的关键因素主要包括杂草高度、横向坡度以及地形凹凸高度,国内外相应标准对这些因素均给出了严格规定,但没有提供相应理论说明。基于阵列天线理论,在理想情况下建立M型GS辐射场及调制度差(difference in depth of modulation,DDM)的数学模型,然后分别建立在杂草、横向坡度和地形凹凸影响下这种信标的DDM计算模型,仿真分析了在这三个因素影响之下GS辐射场的性能,并与法国民航大学开发的专业软件LAGON的仿真结果进行比对。结果表明,建模仿真的结果与相应标准的规定,以及LAGON的仿真结果具有良好的吻合度,证明所给理论方法及所建算法模型的正确性。研究成果可为ILS相应标准的自主更新或制定,以及具有自主知识产权的ILS性能评估软件的开发提供相应理论支持。
