김진욱 Jin-uk Kim

DOI:10.12673/jant.2026.30.3.146 JANT Vol.30(No.3) 146-151, 2026

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This paper proposes a target detection method for airborne radar based on reference range compensation and an RCS-weighted time-velocity Hough transform. In airborne radar systems, platform motion causes range migration, which distorts target trajectories in the range-time domain and degrades Hough transform-based integration performance, resulting in clutter-induced false targets. To address this problem, radar measurements are transformed into a reference coordinate system based on the initial aircraft position, and compensated range values are computed to align target trajectories. In addition, RCS values are used as weighting factors in the Hough accumulator to emphasize target returns and suppress clutter responses during the accumulation process. Experimental results using real flight test data demonstrate that the proposed method reduces false targets and improves detection reliability compared to the conventional Hough transform.

김진욱 Jin-uk Kim

DOI:10.12673/jant.2026.30.3.152 JANT Vol.30(No.3) 152-157, 2026

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This paper analyzes the non-uniform range-dependent search performance that occurs when a fixed elevation beamwidth is used in an airborne maritime surveillance radar, and proposes a range-dependent beamwidth control method to improve it. Owing to the sea-surface projection characteristics of the elevation beam, the down-range footprint length rapidly decreases in the near range, which becomes a major cause of reduced search efficiency. To address this problem, a two-stage beamwidth control structure is applied, combining coarse elevation beamwidth control based on the number of active transmitter/receiver modules (TRMs) with fine adjustment using Taylor tapering. Simulation results show that, compared with the method using only the number of active TRMs, the proposed method maintains the sea-surface footprint length closer to the desired value and effectively expands the search coverage in the near-range region.

김진욱 Jin-uk Kim

DOI:10.12673/jant.2026.30.3.158 JANT Vol.30(No.3) 158-163, 2026

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Large radar targets generate multiple detections along the range dimension, and conventional clustering-based range estimation methods can produce unstable range values depending on the selected representative detection. This range variability degrades target localization and tracking performance. This paper proposes a representative range estimation method using clutter-based target extent estimation. The proposed method estimates the target extent by using the surrounding clutter level and defines an effective range region along the range dimension. The representative range is then calculated from the centroid of the signal within the estimated region, enabling stable range measurement without relying on a single detection point. Experimental results using flight-test data show that the proposed method reduces range variability compared with the conventional method and improves the stability of range estimation, thereby contributing to improved tracking performance.

윤연섭 Yeon-sub Yoon , 서지원 Ji-won Seo , 최승호 Seung-ho Choi , 원완식 Wan-sik Won

DOI:10.12673/jant.2026.30.3.164 JANT Vol.30(No.3) 164-172, 2026

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Wind shear and turbulence are critical hazards during the approach and landing phase, where 50% of aircraft accidents occur. However, existing weather information is mostly limited to airport areas, creating a 3D data gap along standard terminal arrival route (STAR) segments. This study proposes a 3D visualization framework for wind shear at Jeju international airport by mapping high-resolution local data assimilation and prediction system (LDAPS) data to actual aircraft flight paths in both time and space. Hazard zones identified by the calculated wind shear and bulk Richardson number (BRN) were validated using a quantitative band power index derived from frequency analysis (0.5-2.0 Hz) of onboard vibration data. The results show a similar trend between predicted risks and measured vibrations, indicating that this framework can enhance pilot situational awareness and support air traffic controllers in arrival management.

이양기 Yang-ki Lee , 윤석재 Suk-jae Yoon , 강창옥 Chang-ok Kang , 한동균 Dong-gyun Han

DOI:10.12673/jant.2026.30.3.173 JANT Vol.30(No.3) 173-178, 2026

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Array-antenna-based anti-jamming technology is essential for reliable global navigation satellite system (GNSS) reception under high-power jamming. In rifled gun-launch conditions, rapid projectile rotation causes continuous variations in signal direction, limiting the real-time applicability of conventional minimum variance distortionless response (MVDR) and sample matrix inversion (SMI)-based space-time adaptive processing (STAP) due to covariance estimation and matrix inversion. To address this, we propose a sample-by-sample adaptive least mean square (LMS)-STAP algorithm that updates space-time weights using the error between the filter output and a reference response, eliminating matrix inversion for continuous real-time adaptation. Simulation and hardware chamber experiments demonstrate that the proposed LMS-STAP instantly forms deep nulls toward jammers, avoiding the steering lag of conventional SMI methods. Results also confirm that higher operating frequencies increase the weight update rate, ensuring stable convergence and robust anti-jamming performance under severe rotational conditions.

이응돈 Eung-don Lee , 문권한 Gwon-han Mun , 강군석 Kun-seok Kang , 김대호 Dae-ho Kim

DOI:10.12673/jant.2026.30.3.179 JANT Vol.30(No.3) 179-184, 2026

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This paper investigates the feasibility of utilizing the ubiquitous sensor network1 (USN1) frequency band (917~923.5 MHz) for air-to-air (A2A) broadcast links within an urban air mobility (UAM) communication environment, which integrates both A2A broadcast and air-to-ground (A2G) cellular links. Based on technical standards for radio equipment, we analyze whether the sufficient conditions for UAM operation including link signal specifications, communication coverage for tactical conflict management, and link capacity are met. The results confirm that an A2A broadcast link employing a Gaussian minimum shift keying (GMSK) modulation scheme with a modulation rate of approximately 230 kbps, a short message structure of less than 10 ms, and a simplified media avccess control (MAC) protocol based on the slotted ALOHA mechanism is applicable to the USN1 band. Furthermore, this study demonstrates that interference with terrestrial internet of things (IoT) devices can be effectively mitigated by deploying shark-fin antennas capable of multi-directional beamforming on the upper and lower sections of the UAM aircraft.

이한슬 Han-seul Lee , 홍교영 Gyo-young Hong

DOI:10.12673/jant.2026.30.3.185 JANT Vol.30(No.3) 185-190, 2026

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The 433 MHz band offers lower free-space path loss than the 2.4 GHz and 5.8 GHz bands, and its superior penetration and diffraction suit beyond visual line of sight (BVLOS) long-range drone operations. This paper evaluates a 25 kHz bandwidth 433 MHz modem using single-carrier frequency-domain equalization (SC-FDE) and quadrature phase-shift keying (QPSK), measuring link characteristics at various received power levels over a coaxial-cable conducted test with MAVLink traffic from ArduPilot software-in-the-loop (SITL) simulation. The link quality stays above 90% down to -100 dBm for stable bidirectional control, and even at -110 dBm only temporary degradation occurs without disconnection. These results verify at the protocol level that a 433 MHz narrowband modem is viable as a real-time bidirectional control link, providing baseline data for evaluating long-range drone links under outdoor, interference-coexistence conditions.

이민선 Min-sun Lee , 홍교영 Gyo-young Hong

DOI:10.12673/jant.2026.30.3.191 JANT Vol.30(No.3) 191-196, 2026

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This study proposes an asymmetric time division duplexing (TDD) scheme to address uplink-downlink collision issues in a 433 MHz narrowband drone communication link. The proposed method employs a superframe structure that utilizes beacon signals to synchronize time between the ground control station and the drone, while adopting an asymmetric TDD configuration with different uplink and downlink ratios. Experimental results from emulation demonstrate that the proposed approach significantly reduces link quality fluctuations and maintains the target downlink reception period with high stability and reliability. In addition, even under increased uplink traffic conditions, the system sustains high link quality without collisions. These results confirm that the proposed structure is an effective transmission scheme for BVLOS drone operations using a 433 MHz narrowband communication link.

강광천 Kwang-chun Kang , 윤형근 Hyoung-keun Yoon

DOI:10.12673/jant.2026.30.3.197 JANT Vol.30(No.3) 197-203, 2026

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This paper presents the functional architecture and implementation approach of a System Wide Information Management (SWIM)-based Flight Data Processing System (FDPS) for early-stage Urban Air Mobility (UAM) operations. The FDPS supports flight-plan-based traffic management functions of the Provider of Services for UAM (PSU). Since early-stage UAM requires low-altitude corridors, vertiport operational integration, four-dimensional trajectory (4DT) management, supplemental operational information, and multi-stakeholder information sharing, conventional air traffic FDPS functions need to be reorganized for UAM operations. The proposed FDPS consists of five functional areas: flight plan processing and lifecycle management, 4DT reference trajectory management, track-flight plan correlation, conformance monitoring and alerting, and information exchange. Its major functions and SWIM-based information exchange capability were confirmed in the K-UAM Grand Challenge and integrated test environments. This study provides a functional structure and implementation case for flight-plan-centered traffic management in early-stage UAM operations.

강광천 Kwang-chun Kang , 윤형근 Hyoung-keun Yoon

DOI:10.12673/jant.2026.30.3.204 JANT Vol.30(No.3) 204-212, 2026

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Urban air mobility (UAM) operates in environments involving multiple operators and UAM traffic management service providers, requiring real-time sharing of flight plans, surveillance tracks, airspace status, weather information, and vertiport resources. This study designs a common information service (CIS) architecture based on system wide information management (SWIM) to support interoperability and collaborative traffic management among stakeholders. The proposed architecture consists of a registry (REG) for service management, information exchange (IE) for information routing, and an external system interface (ESI) for external system connection and data conversion. REG and IE form the SWIM-based information-sharing layer, while ESI connects this layer with internal UATMSP systems. Through service lifecycle management and dynamic routing, the proposed CIS supports flexible and scalable information exchange among multiple UATMSPs and stakeholders in UAM operational environments.