International standard-compliant vertiport marker detector for instrument landing systems of urban air mobility

Vertiports, dedicated takeoff and landing sites for urban air mobility (UAM), require precision landing technologies for safe operations. The U.S. Federal Aviation Administration (FAA) and European Union Aviation Safety Agency (EASA) have recently introduced new symbols for vertiport identification, yet existing vertiport detectors still predominantly depend on fiducial markers such as ArUco or AprilTag. To address this, this study proposes a vision-based detector for FAA- and EASA-compliant vertiport markers to support precision landing in UAM operations, assuming a nadir-oriented camera viewpoint consistent with regulatory concepts that foresee vertical takeoff and landing segments where standardized vertiport markings provide visual cues. The proposed approach identifies international standard-compliant vertiport identification symbols, estimates relative position and attitude via geometric transformation, and displays pose estimation results on instruments similar to an instrument landing system. The proposed method is validated by analyzing relative position and angle errors in indoor camera and drone flight experiments, where multiple images under diverse relative poses are statistically analyzed and officially defined test criteria are adopted to obtain ground-truth data. The results show high accuracy and robustness under both controlled indoor and real flight conditions, and the instrument visualization demonstrates the practical applicability of the proposed approach to typical UAM landing operations.