• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
• /
• pp.825-827
• /
• 2003

Multi-Spectral Camera(MSC) is a payload on the KOMPSAT-2 satellite to perform the earth remote sensing. The instrument images the earth using a push-broom motion with a swath width of 15 km and a ground sample distance (GSD) of 1 m over the entire field of view (FOV) at altitude 685 Km. The instrument is designed to have an on-orbit operation duty cycle of 20% over the mission lifetime of 3 years with the functions of programmable gain/ offset and on-board image data compression/storage. The MSC instrument has one(1) channel for panchromatic imaging and four(4) channel for multi-spectral imaging covering the spectral range from 450nm to 900nm using TDI CCD Focal Plane Array (FPA). In this paper, the architecture and function of MSC hardware including electrical interface and the operation concept which have been established based on the mission requirements are described. And the design and the preparation of MSC system operation are analyzed and discussed.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 춘계학술대회
• /
• pp.434-437
• /
• 2006

Though numerous drilling has been performed in Jeju Island for development of ground water, the wells are mostly located along the coast lines or at low altitude area, and can hardly be found on the mid-mountain area. Two-dimensional magnetotelluric (MT) surveys have been carried out to cover the lack of geological Informal ion on the mid-mountain area and to figure out any possible structures or evidences for deep geothermal energy remained. Two-dimensional (2-D) inversion of MT data for four survey lines surrounding the Halla mountain show a thick layer having around 10 ohm-m in the depth of a few hundred meters throughout the survey area, which can be considered as the unconsol idated sedimentary layer. And they also show a conductive anomaly extending to more than 2km depth at the central part of each survey lines, which can possibly be related with old volcanic activities during the formation of Halla Mt.. Further seological/geophysical investigations should be followed.

• 대한원격탐사학회지
• /
• 제15권4호
• /
• pp.367-375
• /
• 1999

This paper describes the development, operations, and applications of ROCSAT-l and its Ocean Color Imager (OCI) remote-sensing payload. It is the first satellite program of NSPO. The satellite was successfully launched by Lockheed Martin's Athena on January 26, 1999 from Cape Canaveral, Florida. ROCSAT-l is a Low Earth Orbit (LEO) experimental satellite. Its circular orbit has an altitude of 600km and an inclination angle of 35 degrees. The satellite is designed to carry out scientific research missions, including ocean color imaging, experiments on ionospheric plasma and electrodynamics, and experiments using Ka-band (20∼30GHz) communication payloads. The OCI payload is utilized to observe the ocean color in 7 bands (including one redundant band) of Visible and Near-Infrared (434nm∼889nm) range with the resolution of 800m at nadir and the swath of 702km. It employs high performance telecentric optics, push-broom scanning method using Charge Coupled Devices (CCD) and large-scale integrated circuit chips. The water leaving radiance is estimated from the total inputs to the OCI, including the atmospheric scattering. The post-process estimates the water leaving radiance and generates different end products. The OCI has taken images since February 1999 after completing the early orbit checkout. Analyses have been performed to evaluate the performances of the instrument in orbit and to compare them with the pre-launch test results. This paper also briefly describes the ROCSAT-l mission operations. The spacecraft operating modes and ROCSAT Ground Segment operations are delineated, and the overall initial operations of ROCSAT-l are summarized.

• 한국추진공학회지
• /
• 제22권4호
• /
• pp.133-140
• /
• 2018

최근 친환경적인 항공용 추진시스템에 대한 관심과 필요성이 더욱 부각되면서 다양한 전력원을 조합하여 임무를 수행할 수 있는 무인기 및 추진시스템 개발에 많은 연구가 이루어지고 있다. 본 논문에서는 태양광발전을 기반으로 하는 무인기의 복합추진계통의 구성품을 하나의 시스템으로 통합하여 계통의 안정성 및 출력을 확인하는 시험과 실 기체에 탑재하여 지상에서 통합검증시험을 수행하였고, 이를 통해 비행시험 전 시스템의 기능 및 정상작동 여부를 확인하였다.

• Journal of Astronomy and Space Sciences
• /
• 제35권4호
• /
• pp.295-308
• /
• 2018

In this study, orbit determination (OD) simulation for the Korea Pathfinder Lunar Orbiter (KPLO) was accomplished for investigation of the observational arc-length effect using a sequential estimation algorithm. A lunar polar orbit located at 100 km altitude and $90^{\circ}$ inclination was mainly considered for the KPLO mission operation phase. For measurement simulation and OD for KPLO, the Analytical Graphics Inc. Systems Tool Kit 11 and Orbit Determination Tool Kit 6 software were utilized. Three deep-space ground stations, including two deep space network (DSN) antennas and the Korea Deep Space Antenna, were configured for the OD simulation. To investigate the arc-length effect on OD, 60-hr, 48-hr, 24-hr, and 12-hr tracking data were prepared. Position uncertainty by error covariance and orbit overlap precision were used for OD performance evaluation. Additionally, orbit prediction (OP) accuracy was also assessed by the position difference between the estimated and true orbits. Finally, we concluded that the 48-hr-based OD strategy is suitable for effective flight dynamics operation of KPLO. This work suggests a useful guideline for the OD strategy of KPLO mission planning and operation during the nominal lunar orbits phase.

• Advances in aircraft and spacecraft science
• /
• 제11권1호
• /
• pp.33-53
• /
• 2024

This paper presents a comprehensive investigation into the optimization of Flight Management Systems (FMS) with a particular emphasis on data processing efficiency by conducting a comparative study with conventional methods to edge-computing technology. The objective of this research is twofold. Firstly, it evaluates the performance of FMS navigation systems using conventional and edge computing methodologies. Secondly, it aims to extend the boundaries of knowledge in edge-computing technology by conducting a rigorous analysis of terrain data and its implications on flight path optimization along with communication with ground stations. The study employs a combination of simulation-based experimentation and algorithmic computations. Through strategic intervals along the flight path, critical parameters such as distance, altitude profiles, and flight path angles are dynamically assessed. Additionally, edge computing techniques enhance data processing speeds, ensuring adaptability to various scenarios. This paper challenges existing paradigms in flight management and opens avenues for further research in integrating edge computing within aviation technology. The findings presented herein carry significant implications for the aviation industry, ranging from improved operational efficiency to heightened safety measures.

• Asian Journal of Atmospheric Environment
• /
• 제8권3호
• /
• pp.162-174
• /
• 2014

An abnormal decrease in ozonesonde sensor signal occurred during air-pollution study campaigns in November 2011 and March 2012 in Mexico City Metropolitan Area (MCMA). Sharp drops in sensor signal around 5 km above sea level and above were observed in November 2011, and a reduction of signal over a broad range of altitude was observed in the convective boundary layer in March 2012. Circumstantial evidence indicated that $SO_2$ gas interfered with the electrochemical concentration cell (ECC) ozone sensors in the ozonesonde and that this interference was the cause of the reduced sensor signal output. The sharp drops in November 2011 were attributed to the $SO_2$ plume from Popocat$\acute{e}$petl volcano southeast of MCMA. Experiments on the response of the ECC sensor to representative atmospheric trace gases showed that only $SO_2$ could cause the observed abrupt drops in sensor signal. The vertical profile of the plume reproduced by a Lagrangian particle diffusion simulation supported this finding. A near-ground reduction in the sensor signal in March 2012 was attributed to an $SO_2$ plume from the Tula industrial complex north-west of MCMA. Before and at the time of ozonesonde launch, intermittent high $SO_2$ concentrations were recorded at ground-level monitoring stations north of MCMA. The difference between the $O_3$ concentration measured by the ozonesonde and that recorded by a UV-based $O_3$ monitor was consistent with the $SO_2$ concentration recorded by a UV-based monitor on the ground. The vertical profiles of the plumes estimated by Lagrangian particle diffusion simulation agreed fairly well with the observed profile. Statistical analysis of the wind field in MCMA revealed that the effect Popocat$\acute{e}$petl was most likely to have occurred from June to October, whereas the effect of the industries north of MCMA, including the Tula complex, was predicted to occur throughout the year.

• Journal of Forest and Environmental Science
• /
• 제35권4호
• /
• pp.248-257
• /
• 2019

We chose the Mt. Dalum area (located in Gijang-gun, Busan, Korea) for our survey, particularly The pine wilt disease zone and the non-permanent control area. This study investigates the effect of pine wilt disease on the distribution of beetle species in the process of ecosystem change due to insect control; pine forests treated for pine wilt disease were divided into insect control and non-control sites, respectively. The results of this study are as follows. Twen tyseven species belongs to 12 families were identified from 969 ground beetles collected from this sites. Species richness was the highest in Coleoptera (6 species, 469 individuals). In the control site, 21 species belongs to 10 families were identified from 228 individuals, while 24 species of 11 families from 533 individuals in the non-control area. The highest number of species were noted in June and July from the non- control and control sites, respectively. The highest number of insects in control and non-control sites was observed in July, while the lowest in September. Sipalinus gigas gigas, Spondylis buprestoides, Plesiophthalmus davidis, Calosoma maximowiczi, Damaster jankowskii jankowskii, and Damaster smaragdinus were captured in both study sites. Episomustur ntus and Glischrochilus ipsoides were only captured in the control site, while Macrodorcas rectus rectus and Pheropsophus javanus were only captured in the non-control site. Six beetles and five species (such as Calosoma maximowiczi) were found in the control site and six species (including Damaster smaragdinus) in the non-control site. The species distributions by altitude were 163, 518, and 258 individuals, at 100, 200 and 300 m sites, respectively. The diversity, evenness, and dominance indices in the control area were 0.764, 0.812, and 0.367, respectively. The diversity, evenness, and dominance indices in the non-control area were 0.927, 0.837, and 0.352, respectively. The similarity index between the control and non-control area was 80%.

• 대한토목학회논문집
• /
• 제40권2호
• /
• pp.257-264
• /
• 2020

현재 무인항공사진측량을 이용한 지도제작의 지형·지물 묘사는 주로 벡터화로 이루어지고 있다. 그러나 벡터화는 평면과 표고 위치를 별도로 취득하기 때문에 시간이 많이 소요되고 수치표면모델에서 표고값을 추출 할 때 과대 오차가 발생될 수 있다. 이에 3차원 공간정보를 동시에 취득가능한 수치도화의 필요성이 증가하고 있으나, 고가의 도화장비가 필요하고 무인항공영상의 수치도화 기술이 불완전한 단점이 있다. 이에 본 연구에서는 저가의 시스템으로 수치도화가 가능한 Menci사의 StereoCAD를 이용하여 지형·지물의 묘사정확도를 분석 평가하였다. 무인항공영상의 취득은 Phantom4 pro에 FC 6310 카메라를 탑재하여 비행고도 90 m에서 GSD (Ground Sample Distance) 3 cm로 촬영하였다. 정확도 분석은 검사점과 점·선·면형 레이어별 모서리에 대한 지상측량결과와 도화결과의 3차원 좌표의 차이를 산출하여 비교하였다. 그 결과 검사점의 RMSE는 평면 0.048 m, 표고 0.078 m이고, 레이어별 RMSE는 평면이 0.104~0.127 m, 표고는 0.086~0.092 m로 나타나 무인항공영상의 입체도화로 1:1,000 수치지형도 제작의 가능성을 입증할 수 있었다.

• 한국환경생태학회지
• /
• 제34권6호
• /
• pp.558-572
• /
• 2020

본 연구는 백두대간 지리산권역 내 훼손지의 유형을 분류하고, 각 훼손 유형별 실태조사를 통해 훼손 정도를 파악하여 훼손지의 복원 방향을 제시하기 위한 기초자료로 활용하기 위해 수행되었다. 지리산권역의 훼손실태를 분석한 결과 전체 훼손지의 패치 수는 57개로 확인되었고, 평균고도가 낮고 경사가 완만한 지역일수록 훼손지의 패치 수 및 훼손 면적이 더 넓게 나타났다. 훼손 유형은 초지(폐경지)와 경작지의 비율이 높게 나타나 농업적 토지이용이 주요 훼손 요인으로 분석되었다. 이 중 14개소의 훼손지를 대상으로 실태조사를 수행한 결과, 훼손 유형은 초지, 경작지, 복원지, 벌채지 및 나지로 분류되었다. 각 유형별 교란정도(일년초 및 이년초의 비율, 도시화지수, 교란율)를 분석한 결과, 초지 및 경작지에서는 대부분 초본류로만 구성된 1층 구조의 단순한 식생구조와 교란정도가 높게 나타났다. 소나무 유묘가 다수 식재된 복원지의 경우 2층 구조의 식생구조가 나타났고, 복원사업으로 인한 교란과 인근의 등산로로 인해 귀화식물의 유입이 다른 훼손지에 비해 특히 높게 나타났다. 나지의 경우 고도가 높아 귀화식물의 유입은 낮았지만, 일년초와 이년초의 비율이 높게 나타나 조사된 모든 유형의 훼손지는 천이 초기단계로 판단되었다. 훼손 유형별 군락을 서열화한 결과, I 축상의 복원지, 경작지, 초지, 벌채지 및 나지 순으로 나타나 훼손 유형별로 구분되어 배열되는 경향을 보였다. 또한 훼손 유형별 조사지와 참조생태계의 군락을 서열화한 결과, 종조성의 차이를 확인할 수 있었다. 이처럼 생태적 복원 절차에 따라 식생정보에 기초한 훼손 유형별 실태를 진단하고, 진단 결과와 함께 참조생태계와의 종조성의 차이를 확인함으로써 향후 복원 목표 및 복원 방향 설정의 기초자료로 활용하고자 한다.