• Title/Summary/Keyword: Multi-aperture

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Potential Use of Airborne Synthetic Aperture Radar to Monitor Agricultural Land Uses: A Case Study in Thailand

  • Wanpiyarat, V.;Buapradubkul, D.;Chutirattanaphan, S.
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.44-46
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    • 2003
  • In 1996, Thailand's participation in the Pacific Rim as a part of NASA's Mission to Planet Earth (MTPE) Program, was titled 'AIRSAR Thailand Project'. In this project the Department of Land Development utilized Topographic SAR (TOPSAR) which had multi-frequencies: C band, L band, and P band with multi-polarization: HH, VV, and HV as well as C band VV DEM. Satellite data such as LANDSAT TM was also utilized for optimal use. Results of AIRSAR image processing including data fusion among difference wavelength bands and polarization revealed the quality of AIRSAR that best suit for detection of agricultural land uses. The HH-L band AIRSAR was proven to be useful to distinguish among crop types when combined with appropriate data. The HH, VV, and HV-P band enhanced surface characteristics of swamp forest and wetland. In addition, TOPSAR has its great advantage for identification of salt farms and shrimp ponds.

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Synthetic Aperture Radar Target Detection Using Multi-Cell Averaging CFAR Scheme (다중 셀 평균 기반 CFAR 검출을 이용한 SAR 영상 표적 탐지 기법)

  • Song, Woo-Young;Rho, Soo-Hyun;Jung, Chul-Ho;Kwag, Young-Kil
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.21 no.2
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    • pp.164-169
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    • 2010
  • Since the range and Doppler resolution of the synthetic aperture radar(SAR) image becomes very high, the target detection accuracy can be significantly increased, but the computational burden is also increased. The conventional single-cell based CFAR detector performs the target detection on every single cell basis, thus it causes the serious increment of the computational load. In this paper, the improved two-step MCA-CFAR detector is proposed for the improvement of the target detection as well as the reduction of computational load: the first step is to use the MCA-CFAR, and the second step is to use the single-cell based CFAR detection in the expected target area for final decision. The performance of the proposed algorithm is compared with the conventional single-cell based CFAR and MCA-CFAR on SAR images.

Study on the Forest Observation in Kushiro Wetland by using Dual-Frequency and Fully Polarimetric Airborne SAR (Pi-SAR) Data

  • Nakamura Kazuki;Wakabayashi Hiroyuki;Shinsho Hisashi;Maeno Hideo;Uratsuka Seiho;Nadai Akitsugu;Umehara Toshihiko;Moriyama Toshifumi
    • Proceedings of the KSRS Conference
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    • 2004.10a
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    • pp.405-409
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    • 2004
  • We chose the Kushiro wetland in Hokkaido, Japan, as a test site to monitor wetland areas. Synthetic aperture radar (SAR) can carry out continuous observation in any weather conditions, and can therefore be used to observe high humidity areas such as wetlands. We applied multi-parameter SAR data (dual-frequency, multi-polarization, and multi-incidence angle) to monitoring the wetland forest. To find the optimum incidence angle and polarization for monitoring the wetland biomass, a simple backscattering model of wetland vegetation was developed and applied to estimate backscattering coefficients for different biomass and surface conditions.

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Spaceborne High Speed Data Link Design for Multi-Mode SAR Image Data Transmission

  • Kwag, Young-Kil
    • Journal of electromagnetic engineering and science
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    • v.2 no.1
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    • pp.39-44
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    • 2002
  • A high speed data link capability is one of the critical factors in determining the performance of the spaceborne SAR system with high resolution because of the strict requirement far the real-time data transmission of the massive SAR data in a limited time of mission. In this paper, based on the data lint model characterized by the spaceborne small SAR system, the high rate multi-channel data link module is designed including link storage, link processor, transmitter, and wide-angle antenna. The design results are presented with the performance analysis on the data link budget as well as the multi-mode data rate in association with the SAR imaging mode of operation from high resolution to the wide swath.

A Study on Parallel Performance Optimization Method for Acceleration of High Resolution SAR Image Processing (고해상도 SAR 영상처리 고속화를 위한 병렬 성능 최적화 기법 연구)

  • Lee, Kyu Beom;Kim, Gyu Bin;An, Sol Bo Reum;Cho, Jin Yeon;Lim, Byoung-Gyun;Kim, Dong-Hyun;Kim, Jeong Ho
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.46 no.6
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    • pp.503-512
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    • 2018
  • SAR(Synthetic Aperture Radar) is a technology to acquire images by processing signals obtained from radar, and there is an increasing demand for utilization of high-resolution SAR images. In this paper, for high-speed processing of high-resolution SAR image data, a study for SAR image processing algorithms to achieve optimal performance in multi-core based computer architecture is performed. The performance deterioration due to a large amount of input/output data for high resolution images is reduced by maximizing the memory utilization, and the parallelization ratio of the code is increased by using dynamic scheduling and nested parallelism of OpenMP. As a result, not only the total computation time is reduced, but also the upper bound of parallel performance is increased and the actual parallel performance on a multi-core system with 10 cores is improved by more than 8 times. The result of this study is expected to be used effectively in the development of high-resolution SAR image processing software for multi-core systems with large memory.

Study on Ship Detection Using SAR Dual-polarization Data: ENVISAT ASAR AP Mode

  • Yang, Chan-Su;Ouchi, Kazuo
    • Korean Journal of Remote Sensing
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    • v.24 no.5
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    • pp.445-452
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    • 2008
  • Preliminary results are reported on ship detection using coherence images computed from cross-correlating images of multi-look-processed dual-polarization data (HH and HV) of ENVISAT ASAR. The traditional techniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, and therefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the mean amplitude of surrounding sea clutter. The proposed method utilizes the property that the multi-look images of ships are correlated with each other. Because the inter-look images of sea surface are covered by uncorrelated speckle, cross-correlation of multi-look images yields the different degrees of coherence between the images and water. In this paper, the polarimetric information of ships, land and intertidal zone are first compared based on the cross-correlation between HH and HV images, In the next step, we examine the technique when the dual-polarization data are split into two multi-look images, It was shown that the inter-look cross-correlation method could be applicable in the performance improvement of small ship detection and the land masking, It was also found that a simple combination of coherence images from each co-polarised (HH) inter-look and cross-polarised (HV) inter-look data can provide much higher target-detection possibilities.

Recent Advances with the 3M PDP High Resolution Rib Replication Process

  • McGuire, P.;Cha, J.C.;Kikuchi, H.;Yoda, A.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08a
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    • pp.313-315
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    • 2007
  • 3M has developed a Precision Replication Process for the production of PDP Barrier Ribs and other display devices. This process, is fast, clean and capable of producing very high resolution (FHD and beyond), high aperture ratio and fine cell structures. Recent advances in materials and process features will be discussed.

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Performance Evaluation of An Earth Observation Camera for Small Satellites (소형 위성용 지구관측 광학카메라의 시험모델 평가)

  • 양호순;강명석;정성근;최영완;김이을;양승욱;김종운;윤지호;김도형
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.134-135
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    • 2003
  • Medium-sized Aperture Camera (MAC)는 근적도궤도(Near Equatorial Orbit) 지구관측위성 MACSAT의 주탑재체로, 우리나라의 (주)쎄트렉아이와 말레이시아의 ATSB社와 오는 2004년 발사를 목표로 공동 개발되고 있다. MAC은 push-broom 방식의 전자광학 탑재체로, 지상해상도 2.5 m를 가지는 PAN band 1개, 지상해상도 5 m를 가지는 Multi-Spectral band 4 개를 가지고, 지상의 swath width는 20 km를 가진다. (중략)

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Optical Alignment of An Earth Observation Camera for Small Satellites (소형 위성용 지구관측 광학카메라의 광학정렬)

  • 김도형;양호순;최영완;김이을
    • Proceedings of the Optical Society of Korea Conference
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    • 2003.07a
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    • pp.136-137
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    • 2003
  • Medium-sized Aperture Camera (MAC)는 근적도궤도(Near Equatorial Orbit) 지구관측위성 MACSAT의 주탑재체로, 우리나라의 (주)쎄트렉아이와 말레이시아의 ATSB社와 오는 2004년 발사를 목표로 공동 개발되고 있다. MAC은 push-broom 방식의 전자광학 탑재체로, 지상해상도 2.5 m를 가지는 PAN band 1개, 지상해상도 5 m를 가지는 Multi-Spectral band 4 개를 가지고, 지상의 swath width는 20 km를 가진다. (중략)

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