김지흥 Jee-heung Kim , 곽용길 Young-kil Kwak , 김기출 Kichul Kim , 박주래 Joo-rae Park

DOI: JANT Vol.24(No.1) 1-8, 2020

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In this research, we develop an airborne equipment radiating S/C-band signal to a target located at a long distance. RF interface of the equipment comprises band-specific transmitters and an broadband antenna to satisfy EIRP(effective isotropic radiated power) requirements. The equipment is in a shape of a POD like an aircraft fuel tank. The measured weight of the equipment is 119.8 kg, the CG(center of gravity) is 1391.35 mm and the MOI(moment of inertia) are 46.07 ± 0.05(I_yy) kg·m², 45.36 ± 0.09(I_zz) kg·m². All results are found to meet the requirements for aircraft installation. To verify flight safety, EMI(electromagnetic interference) tests (RE102, CE102), environmental tests (high/low temperature operation, altitude), intra-system EMC(electromagnetic compatibility) and HERP(hazards electromagnetic radiation personnel) tests have been conducted and all the test results met the requirements. It is confirmed that the equipment could be mounted on the aircraft by meeting all electrical and mechanical requirements.

박제홍 Jehong Park , 홍교영 Gyoyoung Hong , 엄정환 Jeonghwan Eom , 정필한 Pilhan Chong , 홍승범 Seungbeom Hong

DOI: JANT Vol.24(No.1) 9-15, 2020

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Recently, active electronically scanned array (AESA) radar, electro-optical and infrared (EO-IR) and infra-red search and track (IRST) sensors are under development in the Korean fighter experimental(KF-X) project, and AESA radar is currently undergoing preliminary research for flight testing. This paper focuses on the flying test bed (FTB) aircraft operation cases of developed countries in accordance with AESA radar development. As a result, we review domestic laws and regulations related to the airworthiness for FTB aircraft to operate in domestic environment and look for ways to operate FTB aircraft. Therefore, we propose how to selecting, airworthiness and operating FTB aircraft suitable for the domestic environment.

김동민 Dongmin Kim , 김태균 Taegyun Kim , 정회조 Hoijo Jeaong , 석진영 Jinyoung Suk , 김승균 Seungkeun Kim , 김연실 Younsil Kim , 한상혁 Sanghyuck Han

DOI: JANT Vol.24(No.1) 16-27, 2020

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This paper investigates the applicability of optical flow information for unmanned aerial vehicle (UAV) navigation under environments where global navigation satellite system (GNSS) is unavailable. Since the optical flow information is one of important measurements to estimate horizontal velocity and position, accuracy of the optical flow information must be guaranteed. So a navigation algorithm, which can estimate and cancel biases that the optical flow information may have, is suggested to improve the estimation performance. In order to apply and verify the proposed algorithm, an integrated simulation environment is built by designing a guidance, navigation, and control (GNC) system. Numerical simulations are implemented to analyze the navigation performance using this environment.

김연실 Youn-sil Kim , 이은성 Eun-sung Lee

DOI: JANT Vol.24(No.1) 28-36, 2020

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Korea augmentation satellite system (KASS) is the Korean satellite based augmentation system (SBAS) developed by ministry of land, infrastructure, and transport (MOLIT) since 2014. Since KASS is the safety critical system that can affect to the safety of airplane, the software of KASS is developed according to the DO178B software level induced from safety analysis. In case of KASS control station (KCS), most of the software of KCS get assigned software level E in DO178B. In that case, ECSS-Q-ST-80C category D is assigned as a software product assurance standard. In this paper, the software related standard ECSS-E-ST-40C, ECSS-Q-HB-80-04A are analyzed to satisfy ECSS-Q-ST-80C and as a result the software product assurance activities regarding software life cycle and the software quality model, metric is proposed for the product assurance of the KCS software.

신혜경 Heakyung Shin , 이장룡 Jang Ryong Lee

DOI: JANT Vol.24(No.1) 37-46, 2020

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Multi-crew pilot license (MPL) is a new pilot licensing concept introduced and operated by ICAO. Mostly, candidates for MPL are educated and drilled with competency-based trainings (CBTs). In this paper, to present education and training measures for the domestic MPL application, ICAO documents and Korea aviation laws for pilot licensing, domestic and foreign airlines' employee requirements, and status of operations related to MPL system are identified. Also feasibility of MPL application in Korea is reviewed by checking approved domestic aviation training institutions’ capabilities, airlines’ pilot demands, and concerns of airlines and trainees with MPL system. Finally, three education and training measures on MPL application in Korea for the air navigation safety are suggested.

박선배 Sun-bae Park , 유도식 Do-sik Yoo

DOI: JANT Vol.24(No.1) 47-52, 2020

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Direction of arrival (DoA) estimation is a scheme of estimating the directions of targets by analyzing signals generated or reflected from the targets and is used in various fields. Artificial neural networks (ANN) is a field of machine learning that mimics the neural network of living organisms. They show good performance in pattern recognition. Although researches has been using ANNs to estimate the DoAs, there are limitations in dealing with variations of the signal-to-noise ratio (SNR) of the target signals. In this paper, we propose a three-stage ANN algorithm for DoA estimation. The proposed algorithm can minimize the performance reduction by applying the model trained in a single SNR environment to various environments through a ‘noise reduction process’. Furthermore, the scheme reduces the difficulty in learning and maintains efficiency in estimation, by employing a process of DoA shift. We compare the performance of the proposed algorithm with Cramer-Rao bound (CRB) and the performances of existing subspace-based algorithms and show that the proposed scheme exhibits better performance than other schemes in some severe environments such as low SNR environments or situations in which targets are located very close to each other.

김장희 Jang-hee Kim , 홍승현 Seung-hyun Hong , 박병관 Byong-kwan Park , 김복기 Bok-ki Kim , 김효종 Hyo-jong Kim

DOI: JANT Vol.24(No.1) 53-60, 2020

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In this paper, We have studied the structure of a Telemetry Transmitter capable of transmitting variable data rates. This paper proposed a structure combining variable pre-modulation filter with cutoff characteristic with variable input sample rate converter. Variable pre-modulation filter has the same characteristics as pre-modulation filter and is converted to a constant sampling rate without structural changes according to the variable input data rate. We propose a software program that actively controls variable pre-modulation filter and variable input sample rate converter to respond to real-time changing data.