Based on the analysis of the practical measurement data of H-field values at three different sites along the longitudinal direction of the railway, this paper proposes an aerial catenary nonuniform transmission line model to predict longitudinal propagation characteristic of pantograph arcing electromagnetic (EM). According to the theory of EM field, EM emission field value measured at articulated neutral section (ANS) site is converted into the initial current of the contact wire. With the initial current, the current distribution on the contact wire and the EM field distribution along the railway when pantograph slid the ANS could be obtained by the proposed model. The validity of the proposed model is verified by the consistency of the theoretical results and the practical measurement at 0.5 MHz, which is the frequency point of the nondirectional radio beacon (NDB).

The electromagnetic interference caused by electrified high-speed railway (HSR) through the protection areas of nondirectional beacon (NDB) is an important issue, especially when the train passes through the neutral section (NS). In this article, based on the theory of multisection transmission line and considering complex factors, the calculation method of medium-frequency current and electromagnetic emission (EME) on the contact wire (CW) when the train passes through NS is given. The radiation properties of the CW were studied quantitatively and its validity was verified by practical measurement. Then, the influence of HSR on NDB navigation signal is analyzed, and the protection distance of NS is given. This method provides theoretical basis for EME of HSR and guidance for airport site selection.

High-Intensity Radiated Fields (HIRFs) can cause severe interference to airborne GNSS equipment. This paper builds a CST model based on the real structure and evaluates shielding effectiveness (SE) with respect to frequency, material, polarization, angle of incidence, and aperture; anechoic-chamber tests combined with the DO-160G compliance method (Section 20, Class G) are then conducted, and this integrated scheme: (1) validates the simulation’s effectiveness and confirms the HIRF coupling risk; (2) reveals the GNSS failure mechanism—C/N₀ decrease → DOP increase → loss of lock. Subsequently, an equation-based mechanism framework (cavity modes, slot/aperture coupling, waveguide-below-cutoff, thickness attenuation) is proposed, together with an effective-dimension correction, by which a single-point calibration can predict the remaining resonances. Accordingly, mechanism-aligned design strategies are provided (aperture control and honeycomb windows, geometric detuning and local absorbers, high-permeability inserts, multi-polarization and multi-directional protection), achieving predictable, verifiable, and quantifiable improvements in SE.

This study employs CST simulations to analyze the electromagnetic response and cable coupling characteristics of electric vertical takeoff and landing (eVTOL) aircraft under lightning conditions. Based on the SAE ARP5414B standard, lightning zoning was carried out, and three typical strike scenarios—the nose, wing, and vertical tail—were established. Referring to representative lightning current waveforms in SAE ARP5412B, Component A was selected as the primary excitation source. On this basis, the L9(3³) orthogonal design method was applied to evaluate the influence of cable structure, length, and routing method on induced current. The results show that lightning strikes at the nose have the strongest coupling effect on the airframe, with both electric and magnetic fields exhibiting significant spatial distribution. Shielded cables effectively reduce induced current in the conductor core by diverting most of the coupled current through the shielding layer, while unshielded single-core cables demonstrate the weakest resistance to interference. Induced current increases with cable length, and Z-shaped wall-mounted routing produces stronger coupling than straight or suspended routing. This research provides a systematic approach for evaluating indirect lightning effects in eVTOL and offers engineering guidance for electromagnetic protection and cable design.

Electromagnetic compatibility (EMC) impacts of arc discharge from medium-low speed maglev trains on the VHF Data Broadcast (VDB) link of the Ground-Based Augmentation System (GBAS) are systematically investigated. Considering that a single VDB station serves multiple runways, this study evaluates how different placements of the VDB antenna relative to runway thresholds affect its susceptibility to maglev interference. Field measurements of maglev arc radiation under various operational conditions revealed a maximum radiation field strength of 57.76 dBμV/m at 113 MHz. Laboratory experiments further identified a minimum required signal-to-interference ratio (SIR) of 26 dB for reliable VDB signal decoding. Theoretical analyses demonstrate that maintaining a separation greater than 5.73 km between the maglev arc source and runway threshold is necessary to ensure signal integrity. The findings offer practical guidance for airport planning and electromagnetic protection design.

Visible–thermal tiny pedestrian detection in UAV aerial images is crucial for online decision-making in urban security and disaster response. However, the extremely small scale and sparse distribution of pedestrians cause discriminative cues to be submerged by dominant low-frequency background and contextual redundancy during feature learning. Meanwhile, cross-modal spatial misalignment and spatially varying modality reliability hinder stable fine-grained correspondence, thereby degrading fusion quality. To address these issues, QA²FDet is proposed as a quality-aware adaptive alignment fusion network comprising three modules: spectrum-spatial decoupled enhancement module (SDE), cross-modal correspondence mining module (CCM), and prior-informed gated fusion (PGF). SDE leverages the discrete cosine transform to disentangle redundant low-frequency background information, while deep semantic gating propagates high signal-to-noise ratio details into shallow representations to enhance subtle cues of tiny pedestrians and suppress high-frequency noise. To establish fine-grained neighborhood correspondences under slight spatial offsets, thermal-guided local asymmetric cross-attention is designed in CCM. Finally, region-level quality and modality discrepancy are jointly modeled for adaptive cross-modal fusion in PGF. Extensive experiments on multiple UAV-based RGBT detection benchmarks demonstrate that QA²FDet achieves state-of-the-art performance and exhibits strong robustness in challenging aerial scenes.