Plasma wave direction determined by propagation characteristics and remote sensing technology provides important information for understanding not only the local plasma environment but also the global features of space plasma. The wave distribution function method, a direction finding method, derives the directional distribution of wave energy density using a priori information such as the propagation mode, plasma density, and geomagnetic field intensity. The Markov random field model includes a noise integration kernel that corresponds to the noise used for the estimation, which improves the robustness of the model. However, the effectiveness of this noise integration kernel was only verified for the case where the electromagnetic field sensor noise levels were equal. The noise levels of the electromagnetic field sensors on board scientific satellites often change due to the degradation of the sensors during long-term instrument operation. Therefore, we proposed two design methods for a noise integration kernel to improve the estimation accuracy when the noise levels among electromagnetic field sensors are different. In proposed model 1, the noise integration kernel was designed for each sensor, and in proposed model 2, the noise integration kernel was designed with the information that the noise level ratio between the sensors was known. The simulation results showed that proposed model 2 improved the misalignment of the peak in the direction of arrival when the noise levels were different regardless of whether the sensor was parallel or perpendicular to the external magnetic field.

中文翻译：

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波分布函数方法的噪声集成内核设计：具有不同传感器噪声水平的稳健测向

由传播特性和遥感技术决定的等离子体波方向不仅为了解局部等离子体环境，而且为了解空间等离子体的全局特征提供了重要信息。波分布函数法是一种测向方法，它利用传播模式、等离子体密度和地磁场强度等先验信息推导出波能量密度的方向分布。马尔可夫随机场模型包括一个与用于估计的噪声相对应的噪声积分核，提高了模型的鲁棒性。然而，这种噪声集成内核的有效性仅在电磁场传感器噪声水平相等的情况下得到验证。科学卫星上的电磁场传感器的噪声水平通常会由于长期仪器运行期间传感器的退化而发生变化。因此，我们提出了两种噪声集成内核的设计方法，以在电磁场传感器之间的噪声水平不同时提高估计精度。在提出的模型 1 中，为每个传感器设计了噪声集成核，在提出的模型 2 中，利用传感器之间的噪声级比已知的信息设计了噪声集成核。仿真结果表明，无论传感器是平行还是垂直于外部磁场，当噪声水平不同时，所提出的模型 2 改善了峰值在到达方向上的错位。