• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.109-116
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• 2013

To extract the 3D geometric information from SAR(Synthetic Aperture Radar) images, two different techniques, interferometric SAR and radargrammetry, have been widely used. InSAR is most widely used for the generation of precise DEM(Digital Elevation Model) until now. But, Interferometric SAR requires severe temporal correlation over areas covered with vegetation and high relief areas. Because radargrammetry is less sensible to temporal correlation, it can provide better results than interferometric SAR in certain, especially X-band SAR. In this paper, we assess the properties of DEMs generated by radargrammetry using stereo C-band RADARSAT-1 images and X-band TerraSAR-X images.

• 한국지형공간정보학회:학술대회논문집
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• 2002.11a
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• pp.58-65
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• 2002

The most widespread techniques for DEM generation are stereoscopy for optical sensor images and interfereometry for SAR images. These techniques suffer from certain sensor and processing limitations, which can be overcome by the synergetic use of both sensors and DEMs respectively. In this paper, different strategies for fusing SAR and optical data are combined to derive high quality DEM products. The multiresolution wavelet transform, which take advantage of the complementary properties of SAR and stereo optical DEMs, will be applied for the fusion process. By taking advantage of the fact that errors of the DEMs are of different nature using the multiresolution wavelet transform, affected part are filtered and replaced by those of the counterpart and is tested with two sets of SPOT and ERS DEM, resulting in a remarkable improvement in DEM. For the analysis of results, the reference DEM is generated from digital base map(1:5000).

• Current Industrial and Technological Trends in Aerospace
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• v.4 no.2
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• pp.40-48
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• 2006

SAR(Synthetic Aperture Radar, 이하 SAR) 위성영상은 광학 영상과는 달리 기상조건의 영향을 거의 받지 않아 대상지역의 주기적인 모니터링이 가능하며, 특정주파수 영역밴드에서는 지표면 투과탐지가 가능하여 재난, 재해, 국방, 환경 분야 등 점차 활용범위가 확대되고 있는 추세이다. 그간의 고해상도 광학위성영상의 기술 개발이 지속적으로 이루어진 상황이라면 그에 비해 영상처리절차가 비교적 까다롭고 복잡한 SAR 영상에 관한 기술개발은 영상 활용의 가치를 가늠해 볼 때 특히 국내 경우 많이 저조한 실정이다. 이와 같은 상황을 고려해 볼 때 현재 개발되고 앞으로 계획단계에 있는 SAR 지구관측 위성의 개발 동향을 파악함으로서 SAR 영상 활용기반구축 마련 및 장기적인 연구개발 계획수립에도 효과적으로 이용될 수 있을 것으로 생각한다.

• Journal of Astronomy and Space Sciences
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• v.25 no.4
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• pp.445-458
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• 2008

Image chain analysis of synthetic aperture radar (SAR) satellite is one of the primary activities for satellite design because SAR image quality depends on spacecraft bus performance as well as SAR payload. Especially, satellite pointing and stability error make worst effect on the original SAR image quality which is implemented by SAR payload design. In this research, Image chain analysis S/W was developed in order to analyze the SAR image quality degradation due to satellite pointing and stability error. This S/W consists of orbit model, attitude control model, SAR payload model, clutter model, and SAR processor. SAR raw data, which includes total 25 point targets in the scene of $5km{\times}5km$ swath width, was generated and then processed for analysis. High resolution mode (spotlight), of which resolution is 1m, was applied. The results of image chain analysis show that radiometric accuracy is the most degraded due to the pointing error. Therefore, the successful design of attitude control subsystem in spacecraft bus for enhancing the pointing accuracy is most important for image quality.

• Journal of Satellite, Information and Communications
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• v.1 no.1
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• pp.26-39
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• 2006

A synthetic aperture radar (SAR) system can provide all-weather, day and night imaging capability, and thus, is very useful in surveillance for both civil and military applications. In this paper, the X-band spaceborne SAR system design procedure is introduced with the key design parameters for mission and system requirements characterized by the small satellite platform. The SAR imaging mode design technique is presented, and the design results are analyzed for standard mode performance evaluation. In line with the system requirements, the X-band SAR payload and ground reception/processing sub-systems are presented with the key design results and image applications examples. The designed small satellite SAR system shows the wide range of imaging capability, and proves to be an effective surveillance system in light-weight, high-performance and cost-effective points of view.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.6
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• pp.4-16
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• 2011

영상 레이다(Synthetic Aperture Radar: SAR)는 기상조건이나 주야에 관계없이 전천후로 광범위한 지역의 영상을 고해상도로 얻을 수 있는 능동형 전자파 레이다 센서이다. 최근 세계적으로 위성 SAR는 2010년을 기점으로 최근 3~4년 사이에 유사이래 가장 많은 13개 이상의 저궤도 소형 SAR 위성들을 발사함에 따라 비로소 "저궤도 위성 SAR 전성기"로 진입하게 되었다. 우리나라에서도 아리랑위성 5호(KOMPSAT-5)에 SAR를 탑재하는 최초의 레이다 위성을 올해 2011년에 발사할 계획을 가지고 있으나 아직 발사가 지연되고 있다. 본 기고에서는 2011년 9월 27~30일 서울에서 개최된 국제 영상 레이다 학술 대회 APSAR 2011(Asia-Pacific Conference on Synthetic Aperture Radar)의 성공을 기념하여 마련된 SAR 기술 특집호에 최신 위성 SAR 개발 동향을 중심으로 기술 발전 추세와 전망에 대하여 소개한다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.13 no.4
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• pp.21-26
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• 2007

A study on analysis and application of ocean currents information extracted from SAR (Synthetic Aperture Radar) satellite image. The current information extracted from SAR satellite image is not real vector information but scalar information in normal direction of orbital path. To correct current information extracted from satellite image, observation of currents in the field is carried out at the same time and area as those of satellite image. In the analysis, current information extracted from satellite image is corrected by using observed ones. By this correction, the speed and the direction of current can be estimated. The extract current information seem to agree well with the observed ones.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.117-125
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• 2014

Korea's first X-band SAR satellite KOMPSAT-5 has been launched in 2013, so the research related to the X-band SAR satellite image is required to increase the utilization of KOMPSAT-5. In this study, we generated a DEM(Digital Elevation Model) using X-band SAR satellite images based on three methods which are InSAR, radargrammetry and RPC(Rational Polynomial Coefficients), and evaluated the performance of each methods. The four stripmap mode TerraSAR-X images taken in Daejeon were used to generate DEM, and accuracy was evaluated using DEM by IKONOS RPC. As results, DEM produced by the InSAR showed the highest accuracy. Also, we knew that RPC could be effective method if you want to create a large area DEM which contains the various elevation.

• Korean Journal of Remote Sensing
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• v.38 no.6_4
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• pp.1955-1969
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• 2022

Most of the public and private users who use national satellite information such as the KOMPSAT series mainly use Electro-Optical and Infrared (EO/IR) satellite images, and the utilization of Synthetic Aperture Radar (SAR) images is relatively insufficient. As KOMPSAT-5 currently in operation, KOMPSAT-6 and micro SAR satellite constellation systems are scheduled to be launched in the future, the demand for utilization of SAR satellite information is increasing in various fields. Accordingly, it is necessary to possess core technology for SAR utilization that can support the utilization of SAR satellite information for users. Due to the all-weather properties of SAR system, change detection technology is a key application technology. However, until now, the development of technology that automatic change detection and cueing using SAR images is insufficient. Through this study, the requirements of automatic change detection and cueing function using multi-temporal KOMPSAT-5 SAR satellite images were derived and a prototype program was developed. This prototype program aims to secure independent SAR utilization technology and promote the utilization of domestic SAR satellite information by practitioners in public sector organizations in Korea.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.22 no.1
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• pp.88-106
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• 2011

최근 고해상도의 영상 레이다(Syntetic Aperture Radar. SAR) 기술의 급속한 발전으로 기상의 변화에 관계없이 전천후로 지구의 환경 변화를 관측하거냐 고정밀도의 표적 탐지 및 식별이 가능해짐에 따라 레이다 영상을 이용한 활용 분야가 군사 목적의 정밀 감시 정찰뿐만 아니라 과학 및 민수용으로도 활용범위가 넓어지고 있다. SAR의 역사는 1950년대부터 약 50년의 기술 역사를 가지고 있지만 2010년을 기점으로 최근 3~4년 사이에 전 세계적으로 유사 이래 가장 많은 10여개 이상의 저궤도 SAR 위성들을 발사하므로서 비로소 "저궤도 위성 SAR 전성시대"로 진입하게 되었다. 우리나라에서도 최근 다목적 실용위성 5호에 SAR를 탑재하는 최초의 영상 레이다 위성을 2011년 중반에 궤도에 집입시키기 위하여 현재 발사를 준비하고 있다. 본 논문에서는 2011년 9월 26~30일 한국에서 처음으로 개최되는 국제영상 레이다 학술대회(Asia-Pacific Conference on Synthetic Aperture Rader: APSAR 2011)에 즈음하여 위성 SAR 개발 동향을 중심으로 SAR 기술 특정과 활용 기술 및 최근 기술 발전 동향을 소개한다.