Apart from interfering in the communication system of an aircraft, electromagnetic pulses (EMPs) radiated from spark discharge plasma, which is generated during high-speed flight, can also be utilized in passive detection. In order to validate this idea, an experiment on direction of arrival (DOA) estimation of a spark discharge plasma target using its radiated EMPs is carried out in this paper. A combined time-domain antenna is designed based on the model of spark discharge process and is used to receive the radiated EMPs during the experiment. According to the experimental results, the DOA estimation system with combined antenna is able to obtain the direction information of a spark discharge plasma. Results also show that the estimation performance of elevation angle is better when the actual elevation angle of the discharge plasma target is higher, while the estimation performance of azimuth is opposite. The azimuth angle of a target has very little influence on the DOA estimation. Moreover, the estimation error can be reduced effectively by increasing the aperture size of receiving array. The previously mentioned results provide an approach to locate the discharge plasma source using radiated EMPs with passive detection techniques.

中文翻译：

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组合时域天线估算大气火花放电等离子体到达方向的实验

除了干扰飞机的通信系统外，高速飞行过程中产生的火花放电等离子体辐射的电磁脉冲（EMP）也可用于被动检测。为了验证该想法，本文进行了利用其辐射EMP对火花放电等离子体靶的到达方向（DOA）估计进行实验。基于火花放电过程模型设计了组合式时域天线，用于接收实验过程中辐射的电磁脉冲。根据实验结果，结合天线的DOA估计系统能够获得火花放电等离子体的方向信息。结果还表明，当放电等离子体靶的实际仰角较高时，仰角的估计性能较好，而方位角的估计性能则相反。目标的方位角对DOA估计的影响很小。此外，通过增加接收阵列的孔径尺寸可以有效地减小估计误差。前面提到的结果提供了一种使用辐射EMP和无源检测技术来定位放电等离子体源的方法。