• Bulletin of the Korean Space Science Society
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• 2010.04a
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• pp.35.3-35.3
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• 2010

항공용 지역위성항법 보강시스템(Ground Based Augmentation System, GBAS)은 지상에서 위성항법시스템에 대한 위치보정정보와 무결성 정보를 생성 및 제공하여 공항 주변 항공기의 정밀 이착륙을 돕는 지상기반의 시스템이다. 이 시스템은 기본적으로 위성항법신호를 사용하기 때문에 전리층 영향을 받게 되는데 특히 전리층 폭풍(Ionospheric storm)의 경우 공간적으로 급격한 위치오차 차이를 발생시키기 때문에 안정적인 항공기의 정밀이착륙을 위해서는 전리층 폭풍의 영향을 최소화 하는 것이 중요하다. 이를 위하여 현재 항공용 지역위성항법 보강시스템의 지상시스템(Ground Facility)과 항공기 탑재시스템에서의 전리층 폭풍에 대한 정확한 감시와 전리층 폭풍의 지배적 영향을 받는 위상항법신호를 제거하거나 보완하는 방식 등 전리층 폭풍의 영향을 최소화하기 위한 기법들이 계속해서 연구 중이다. 이 논문에서는 2001년과 2003년 미국에서 발생한 전리층 폭풍에 대한 위성항법데이터 분석 결과와 기존의 연구결과를 기반으로 전리층 폭풍에 대한 모델링과 지상시스템과 항공기 간의 공간적 상이현상(Spacial decorrelation)을 고려하여 전리층 폭풍이 항공기 이착륙에 미치는 영향에 대한 분석 결과를 제시한다. 전리층 폭풍에 대한 수학적 모델링을 하기 위해서는 전리층 폭풍의 물리적 특성에 대한 이해와 전리층 폭풍 발생 시 획득한 위성항법 데이터를 이용한 통계학적 분석이 선행되며 이러한 분석결과와 항공기 이착륙에 절차를 반영하여 항공기에 미치는 영향 분석을 위한 수학적 모델을 완성하였다. 완성된 모델을 국내 공항에서 실제 비행시험을 통하여 획득한 위성항법데이터에 적용하여 전리층 폭풍이 국내 공항에서 항공기 이착륙에 어떠한 영향을 미치는지를 분석하였다. 또한, 대표적 전리층 폭풍 감지기법 중 하나인 Code-Carrier Divergence Test 알고리즘을 적용한 결과도 함께 제시하였다. 이 논문의 결과는 항공용 지역위성항법 보강시스템에 대한 전리층 폭풍의 영향을 최소화하기 위한 기법 연구의 기반이 되며 시스템의 성능평가를 위한 다양한 시뮬레이션환경의 하나로서도 활용이 가능할 것이다.

• Korean Journal of Remote Sensing
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• v.19 no.4
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• pp.291-305
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• 2003

The cost of deploying Geological and Environmental information gathering systems, especially when such systems obtain remote sensing and photographic data through the use of commercial satellites and aircraft. Besides the high cost equipment required, adverse weather conditions can further restrict a researcher's ability to collect data anywhere and anytime. To mitigate this problem, we have developed a compact, multi-spectral automatic Aerial photographic system. This system's Multi-spectral camera is capable of the visible (RGB) and infrared (NIR) bands (3032*2008 pixel). It consists of a thermal infrared camera and automatic balance control, and can be managed by a palm-top computer. Other features includes a camera gimbal system, GPS receiver, weather sensor among others. We have evaluated the efficiency of this system in several field tests at the following locations: Kyongsang-bukdo beach, Nakdong river (at each site of mulkeum-namji and koryung-gumi), and Kyungahn River. Its tested ability in aerial photography, weather data, as well as GPS data acquisition demonstrates its flexibility as a tool for environmental data monitoring.

• Journal of Aerospace System Engineering
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• v.17 no.4
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• pp.1-9
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• 2023

Recently, as Synthetic Aperture Radar (SAR), communication, and signal surveillance missions of spacecraft have become more advanced, research has been actively conducted on the deployable large mesh antenna system with excellent storage efficiency compared to the deployment area, and light weight. Deployable Mesh antennae are characterized by an increase in the number of Openings Per Inch (OPI), which is a measure of mesh weaving density as the mission frequency band increases, and this OPI change directly affects the thermal optical properties of the mesh antenna, so research on this is required. In this paper, to verify the thermal relationship between the optical properties of the mesh and antenna reflector, thermal sensitivity analysis between the mesh and the antenna reflector is performed by in-orbit thermal analysis with various optical characteristics of the mesh based on existing overseas research cases. In addition, the temperature gradient effect of the mesh reflector is analyzed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.13 no.2
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• pp.73-80
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• 2014

A camera module that gathers visual information via aerial observation reconnaissance is equipped inside a gimbal structure. This gimbal structure system must reduce dynamic responses in order to obtain clear images under all circumstances. Among many design specifications for this system, there is MIL-STD-810G as a shock standard. This specification indicates a limitation of the acceleration of the camera module under a base shock excitation on the gimbal structure. The satisfaction of this condition can usually be proved by experiment, because it includes bearings and dynamic isolators made of rubber. Numerical analysis must be proposed for design improvement of the gimbal structure. To achieve this goal, transient response analysis for the base shock excitation was performed using the finite element method. Experimental results were compared with numerical solutions and it is shown that the present method is useful.

• The Journal of the Korea institute of electronic communication sciences
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• v.19 no.1
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• pp.233-240
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• 2024

In this study, we introduce a system for real-time monitoring of field conditions within an industrial complex using a 5G network UAV (: Unmanned Aerial Vehicle). When a monitoring event occurs in a sensor mounted on a UAV (detection of fire, harmful gas, or industrial disaster type human accident), key information from the sensor is transmitted to the UAS (: Unmanned Aerial System) application server. As a result of this information transmission and processing, managers or operators of the Industrial Complex Corporation were able to secure legal basis data for fatal accidents, fires, and detection of harmful gases at sites within the Industrial Complex Corporation through trigger processing for each accident risk situation.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.10 no.2
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• pp.63-70
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• 1996

In this paper, we propose the low sldelobe digital doppler filter bank design algorithm which is practically applicable to coherent radar equipment in complex air-defense system. Using the proposed algorithm, we can obtain a digital doppler filter bank of lower peak sidelobe level and higher clutter suppression capability. In this method, it is possible to achieve higher target-detectability without loss of Target SNR. The proposed algorithms are verified by simulations and experiments.

• Journal of Advanced Navigation Technology
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• v.19 no.5
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• pp.403-410
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• 2015

ADS-B can provide high accurate position information and faster update rate than Radar system and it is a technique that can supplement or replace the Radar. Recently ADS-B has been applied to the actual aircraft operation because to increase air transportation traffic and required to high accurate surveillance. In this study, we surveyed analysis of position deviation distribution analysis and received actual ADS-B trajectory data for conformed precise surveillance on the near airport area using ADS-B message. For that, we received the precision instrument approach ADS-B trajectory data using instrument landing system, and can analyse about target deviation distribution on the final approach segment about precision instrument approach. The result of analysis is mean distance of target deviation -0.04 m and standard deviation 6.71 m on between ADS-B target and extended runway centerline. Also that is to conformed the ADS-B message trajectory available to provide relatively exact surveillance information.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.25.5-26
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• 2009

인류의 활동 무대가 우주공간으로 확대됨으로써 우주기상에 의한 피해를 최소화 할 수 있는 조치가 요구됨에 따라 우주기상에 대한 감시 및 예 경보 업무가 필요해 졌다. 미국은 이미 우주기상 감시와 예보의 필요성을 인식하고 해양대기청(NOAA), 미 공군(USAF), 항공우주국(NASA), 내무부(DOI), 에너지부(DOE), 과학재단(NSF)이 연합하여 1996년 국가우주기상 프로그램(National Space Weather Program)을 수립.추진하고 있다. 특히 정부연구 기관인 NOAA 산하 우주기상예보센터(Space Weather Prediction Center; SWPC)와 미 공군 기상국(AFWA)은 우주기상 자료 생산, 수집, 자료 센터 운용, 연구 지원 및 예 경보 업무를 공동으로 수행하고 있으며 관련 자료 및 정보의 교환 등 매우 밀접하게 상호협력하고 있다. 최근 정부는 과학기술 7대 중점투자 분야별 중점육성후보기술로서 우주감시체계개발기술을 포함한 국가과학기술기본계획(577전략)을 수립 발표하였으며, 대한민국 공군은 향후 우주군 창설을 목표로 우주전력 기반체계구축을 계획하고 있다. 국방부는 2012년 전시작전통제권 환수에 대비한 독자적인 작전지휘능력 확보가 필요한 상황이며, 미래의 한국군 독자적 네트웍 중심 전장(NCW: Network Central Warfare) 체계 구축을 위해서는 미 공군의 "우주기상작전센터"와 같은 우주기상 예 경보 체계 구축이 요구된다. 이 연구에서는 군의 독자적 우주작전능력 확보를 위한 우주기상 예 경보 체계 구축 방향을 제시하고자 사전기반 연구를 수행하였다. 그 내용으로 우주기상에 대한 개요 및 우주기상의 변화에 따른 국내외 영향을 조사하고 국내외 우주기상 예 경보 시스템을 소개하고자 한다. 또한, 미공군의 우주기상 활용 상태를 점검하여 한국 공군을 위한 우주기상 예 경보 체계 구축 및 인력과 기술 확보에 대한 방안을 제시하고자 한다.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.501-506
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• 2011

The study and techniques of system engineering have been applied to various fields including space-air, national defense division in advanced countries. Korea is currently in the early stages of introducing system engineering scheme in railway system and national defense division restrictedly. As theory and application of system engineering covers a wide scope, documents management and requirement analysis technology applied to establishment of standard and core unit development of the research target. The techniques which are historical management and trace among standards for establishment of standard are introduced using SE tools and participating agencies shared the information by constructing of database from all documents which are generated from the project. Through the functional analysis of the requirements for the intelligent station monitoring system in basic design stage, established requirements are verified and will be made official announcement as standard of the intelligent station monitoring system.

• Journal of Advanced Navigation Technology
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• v.27 no.6
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• pp.804-814
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• 2023

Various buildings are scattered below and around the flight path of UAM (Urban Air Mobility), which flies within a densely populated urban area. And the vertiport used by UAM for takeoff and landing is located on a flat area within the city center or on top of a building. As such, UAM operates in densely populated urban areas, and vertiports for takeoff and landing are installed in densely populated areas, requiring a very high level of safety. In particular, for safe landing of UAM, it is necessary to monitor the approach status of UAM approaching the vertiport from the final approach course and provide approach information. Accordingly, to monitor the UAM vertiport final approach path, research was conducted on technology that utilizes optical equipment that can be installed in a narrow site and has the advantage of reducing the burden of electromagnetic waves.