• Title/Summary/Keyword: 화성탐사

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OPTIMAL TRAJECTORY CORRECTION MANEUVER DESIGN USING THE B-PLANE TARGETING METHOD FOR FUTURE KOREAN MARS MISSIONS (B-평면 조준법을 이용한 화성 탐사선의 궤적 보정을 위한 최적의 기동 설계)

  • Song, Young-Joo;Park, Eun-Seo;Yoo, Sung-Moon;Park, Sang-Young;Choi, Kyu-Hong;Yoon, Jae-Cheol;Yim, Jo-Ryeong;Choi, Joon-Min;Kim, Byung-Kyo
    • Journal of Astronomy and Space Sciences
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    • v.22 no.4
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    • pp.451-462
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    • 2005
  • Optimal Trajectory Correction Maneuver (TCM) design algorithm has been developed using the B-plane targeting method for future Korean Mars missions. For every-mission phase, trajectory informations can also be obtained using this developed algorithms which are essential to design optimal TCM strategy. The information were computed under minimum requiring perturbations to design Mars missions. Spacecraft can not be reached at designed aim point because of unexpected trajectory errors, caused by many perturbations and errors due to operating impulsive maneuvers during the cruising phase of missions. To maintain spacecraft's appropriate trajectory and deliver it to the designed aim point, B-plane targeting techniques are needed. A software NPSOL is used to solve this optimization problem, with the performance index of minimizing total amount of TCM's magnitude. And also executing time of maneuvers on be controlled for the user defined maneuver number $(1\~5)$ of TCMs. The constraints, the Mars arrival B-plane boundary conditions, are formulated for the problem. Results of this work show the ability to design and analyze overall Mars missions, from the Earth launch phase to Mars arrival phase including capture orbit status for future Korean Mars missions

Analysis of Optical Satellite Images and Pyroclastic Flow Inundation Model for Monitoring of Pyroclastic Flow Deposit Area (화성쇄설류 분출 지역의 감시를 위한 광학영상과 화성쇄설류 범람 예측 모델링 분석)

  • Cho, Minji;Lee, Saro;Lee, Chang-Wook
    • Korean Journal of Remote Sensing
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    • v.30 no.2
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    • pp.173-183
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    • 2014
  • Field survey research on damages caused by volcanic activities has plenty of difficulties due to human resources, safety and costs issues. Remote sensing application using satellite image is one of very useful tools to overcome those issues. In this study, we monitored the volcanic activities of Sinabung volcano in 2010, which is located in Sumatra island, Indonesia by using Landsat 7 ETM+ satellite images acquired on 17 April, 2009 and 30 July, 2012. We found that the area of pyroclastic flow inundation after 2010 has been tripled roughly, since extracting the pyroclastic flow inundation before and after 2010 eruption from classification. The result from modeling of pyroclastic flow inundation has been compared with the extracted pyroclastic flow inundation from Landsat 7 ETM+ images. As a result, we confirmed that the length of inundation area from the modeling was calculated to 92% accurate, but the width of inundation area was somewhat imprecisely estimated in the volcanic area having the sharp slope and only calculated to 17% accurate.

화성탐험 르네상스시대 열린다

  • Chae, Yeon-Seok
    • The Science & Technology
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    • no.9 s.412
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    • pp.12-16
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    • 2003
  • AP통신은 평소 6000만 마일 떨어져 있는 지구와 화성 간의 거리가 우리나라 시간으로 8월 27일 오후 6시 51분에 3460만 마일까지 좁혀졌다고 밝혔다. 태양과 화성을 잇는 일직선상에 지구가 위치하는 행성직렬현상(Grand Alignment)은 대략 2.2년을 주기로 발생하며 '대접근'은 15년마다 다가온다. 하지만 이번 대접근은 특별하다. 네안데르탈인이 지구를 지배하던 BC 57617년 9월 12일 이래 약 6만년만에 찾아오는 대접근 중에서도 최대접근에 해당한다. 게다가 이들 두 행성은 오는 2287년 8월 28일에 가서야 다시 가까워지므로 살아있는 지구인이 이런 장관을 지켜볼 수 있는 것은 이번이 마지막 기회이다. 이를 계기로 미국 · 유럽 · 일본은 화성탐사에 나섰다. 그 현장을 소개한다.

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Gravity Anomaly around Boam Deposit, Uljin: Implications on Economic Geology (울진 보암광상 일대 중력 이상: 광상학적 함의)

  • Oh, Il-Hwan;Heo, Chul-Ho;Shin, Young-Hong
    • Economic and Environmental Geology
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    • v.55 no.5
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    • pp.521-529
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    • 2022
  • Gravity exploration was conducted to determine the distribution of igneous complex related to lithium pegmatite in the Boam deposit of Uljin, Gyeongsangbuk-do, and the spatial relationship with the regional geology and ore bodies were studied. The gravity exploration result shows that the Boam deposit area is characterized by relatively low gravity anomaly that surrounds the deposit. The Boam deposit is located near the southwest-northeast directional boundary of gravity anomalies where igneous complex (granite gneiss) contacts with the Yuli and Wonnam groups in the southeast, Janggun limestone layers in the east-west direction, and Dongsugok metasedimentary rocks. While the western boundary in the southwest-northeast direction is relatively clear, there may also be unknown igneous complex that are not exposed on the surface at the eastern and southern boundaries because a relatively low gravity anomaly surrounds the deposit. The distribution characteristics of these hidden igneous complex will be used as useful data for predicting the distribution of the lithium pegmatite in the future.

Terrain surveying for gully in Svalbard using UAV and comparison with Mars (UAV를 이용한 스발바르 걸리 지형의 측량과 화성 걸리와의 비교)

  • LEE, Jaeyong;OGUCHI, Takashi
    • The Bulletin of The Korean Astronomical Society
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    • v.43 no.1
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    • pp.72.4-73
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    • 2018
  • 북극 스발바르의 사면 지형에는 걸리가 발달되어 있다. 이러한 걸리는, 그 성인에는 여러 의견이 있으나, 화성에도 중고위도를 중심으로 다수 분포한다. 화성의 걸리는 2000년대에 들어 비로소 본격적으로 규명되고 있으나, 지형적 특성으로 인한 탐사의 한계로 지구에 분포하는 유사지형을 통한 비교 연구가 일반적이다(Costard, et al. 2007 등). 이 연구에서는 스발바르의 주도 롱이어비엔에서 UAV을 이용하여 획득한 DEM으로 스발바르 걸리를 측량하고, 이를 화성 중위도의 테라 사이메리아, 테라 시레넘, 노아 키스 테라에 분포하는 걸리와 비교하였다. Longyearbreen 빙하 전방에 위치한 사면을 UAV로 촬영하고, 이를 SfM-MVS(Structure from Motion & MultiView Stereo) 기법으로 3차원 점군 모델과 고해상도 DEM을 제작하여 분석하였다. 화성의 경우 MRO궤도 탐사선이 촬영한 HiRise DTM을 이용하여 분석하였다. 두 걸리는 기후와 지질 조건에 차이가 있음에도 불구하고 유사한 패턴을 보였다. 특히 테라 사이메리아에 위치한 걸리와 롱이어비엔 북사면의 걸리는 기준거리, 단면적, 폭, 경사, 제방 두께 등에서 상당한 정량적 유사관계가 있었다. 이는 두 행성의 걸리가 유사한 성인 및 형성 프로세스를 거쳤을 가능성을 시사한다. 측량 기법과 UAV 의 안정성을 개선시키면 지형 모델의 품질 향상 및 극지에서의 UAV 운용이 용이해질 것으로 기대된다. 또한 스발바르의 기후 요소 및 물리량 적용은 향후 화성 지형연구에도 응용할 수 있을 것으로 사료된다.

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DYNAMIC MODEL DEVELOPMENT FOR INTERPLANETARY NAVIGATION (행성탐사 항행해 결정을 위한 동역학 모델 개발)

  • Park, Eun-Seo;Song, Young-Joo;Yoo, Sung-Moon;Park, Sang-Young;Choi, Kyu-Hong;Yoon, Jae-Cheol;Yim, Jo-Ryeong;Choi, Joon-Min;Kim, Byung-Kyo
    • Journal of Astronomy and Space Sciences
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    • v.22 no.4
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    • pp.463-472
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    • 2005
  • In this paper, the dynamic model development for interplanetary navigation has been discussed. The Cowell method for special perturbation theories was employed to develop an interplanetary trajectory propagator including the perturbations due to geopotential, the Earth's dynamic polar motion, the gravity of the Sun, the Moon and the other planets in the solar system, the relativistic effect of the Sun, solar radiation pressure, and atmospheric drag. The equations of motion in dynamic model were numerically integrated using Adams-Cowell 11th order predictor-corrector method. To compare the influences of each perturbation, trajectory propagation was performed using initial transfer orbit elements of the Mars Express mission launched in 2003, because it can be the criterion to choose proper perturbation models for navigation upon required accuracy. To investigate the performance of dynamic model developed, it was tested whether the spacecraft can reach the Mars. The interplanetary navigation tool developed in this study demonstrated the spacecraft entering the Mars SOI(Sphere of Influence) and its velocity .elative to the Mars was less than the escape velocity of the Mars, hence, the spacecraft can arrive at the target planet. The obtained results were also verified by using the AGI Satellite Tool Kit. It is concluded that the developed program is suitable for supporting interplanetary spacecraft mission for a future Korean Mars mission.