• Title, Summary, Keyword: SAR

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Development a GB-SAR (I) : System Configuration and Interferometry (GB-SAR의 개발 (I) : 시스템 구성과 간섭기법)

  • Lee, Hoon-Yol;Sung, Nak-Hoon;Kim, Jung-Ho;Cho, Seong-Jun
    • Korean Journal of Remote Sensing
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    • v.23 no.4
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    • pp.237-245
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    • 2007
  • GB-SAR (Ground-Based Synthetic Aperture Radar) system is an imaging radar that obtains high resolution 2-D image through a synthetic aperture effect from the accurate linear-motion control of antenna on the ground. The highly versatile system configurations and accurate repeatability of GB-SAR operation allow one to accurately monitor the stability of surface scatterers with millimeter accuracy by SAR interferometry. In this paper we introduce the development of a GB-SAR system and show the possibilities of SAR polarimetry and interferometry such as DInSAR, Cross-Track InSAR, Delta-f InSAR, and PSInSAR.

Ground-Based Rotational SAR System for Field-Experiments (지상 운용 회전형 SAR 시험용 시스템 연구)

  • Hwang, Ji-Hwan;Kwon, Soon-Gu;Shin, Jong-Chul;Oh, Yi-Sok
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.22 no.11
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    • pp.1092-1100
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    • 2011
  • A C-band ground-based rotational SAR system is presented in this paper. The rotaional SAR system is a test-bed for future rotational SAR systems which can be deployed in space and on a tower. The test-bed system is designed for imaging the electromagnetic scattering from earth surfaces and buried targets. This paper also presents the examination results of the generated SAR images. This rotational SAR system is basically consisted of the network-analyzer based HPS(Hongik Polarimetric Scatterometer) and a horizontally rotating arm. Several SAR images were obtained using the rotational SAR system for various target areas. To verify this system, we simulated the SAR images for the rotational SAR using the FDTD algorithm and compared between the measured and simulated SAR images. The rotational SAR system is operated at the center frequency of 5 GHz and various frequency bandwidth within 0.5~2 GHz to change the resolution of SAR images.

Experimental Study on DEM Extraction Using InSAR and 3-Pass DInSAR Processing Techniques (InSAR 및 3-Pass DInSAR 처리기법을 적용한 DEM 추출에 대한 실험 연구)

  • Bae, Sang-Woo;Lee, Jin-Duk
    • The Journal of the Korea Contents Association
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    • v.7 no.3
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    • pp.176-186
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    • 2007
  • As SAR data have the strong point that is not influenced by weather or light amount in comparison with optical sensor data, they are highly useful for temporary analysis and can be collected in time of unforeseen circumstances like disaster. This study is to extract DEM from L-band data of JERS-1 SAR imagery using InSAR and DInSAR processing techniques. As a result of analyzing the extracted coherence and interferogram images, it was shown that the DInSAR 3-pass method produces more suitable coherence values than the InSAR method. The accuracies of DEM extracted from the SAR data were evaluated by employing the DEM derived from the digital topographic maps of 1:5000 scale as reference data. And it was ascertained that baselines between antenna locations largely affect the accuracy of extracted DEM.

High Resolution InSAR Phase Simulation using DSM in Urban Areas (도심지역 DSM을 이용한 고해상도 InSAR 위상 시뮬레이션)

  • Yoon, Geun-Won;Kim, Sang-Wan;Lee, Yong-Woong;Lee, Dong-Cheon;Won, Joong-Sun
    • Korean Journal of Remote Sensing
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    • v.27 no.2
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    • pp.181-190
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    • 2011
  • Since the radar satellite missions such as TerraSAR-X and COSMO-SkyMed were launched in 2007, the spatial resolution of spaceborne SAR(Synthetic Aperture Radar) images reaches about 1 meter at spotlight mode. In 2011, the first Korean SAR satellite, KOMPSAT-5, will be launched, operating at X-band with the highest spatial resolution of 1 m as well. The improved spatial resolution of state-of-the-art SAR sensor suggests expanding InSAR(Interferometric SAR) analysis in urban monitoring. By the way, the shadow and layover phenomena are more prominent in urban areas due to building structure because of inherent side-looking geometry of SAR system. Up to date the most conventional algorithms do not consider the return signals at the frontage of building during InSAR phase and SAR intensity simulation. In this study the new algorithm introducing multi-scattering in layover region is proposed for phase and intensity simulation, which is utilized a precise LIDAR DSM(Digital Surface Model) in urban areas. The InSAR phases simulated by the proposed method are compared with TerraSAR-X spotlight data. As a result, both InSAR phases are well matched, even in layover areas. This study will be applied to urban monitoring using high resolution SAR data, in terms of change detection and displacement monitoring at the scale of building unit.

Radarsat-1 ScanSAR Quick-look Signal Processing and Demonstration Using SPECAN Algorithm (SPECAN 알고리즘을 이용한 Radatsat-1 ScanSAR Quick-look 신호 처리 및 검증 알고리즘 구현)

  • Song, Jung-Hwan;Lee, Woo-Kyung;Kim, Dong-Hyun
    • Korean Journal of Remote Sensing
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    • v.26 no.2
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    • pp.75-86
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    • 2010
  • As the performance of the spaceborne SAR has been dramatically enhanced and demonstrated through advanced missions such as TerraSAR and LRO(Lunar Reconnaissance Orbiter), the need for highly sophisticated and efficient SAR processor is also highlighted. In Korea, the activity of SAR researches has been mainly concerned with SAR image applications and the current SAR raw data studies are mostly limited to stripmap mode cases. The first Korean spaceborne SAR is scheduled to be operational from 2010 and expected to deliver vast amount of SAR raw data acquired from multiple operational scenarios including ScanSAR mode. Hence there will be an increasing demand to implement ground processing systems that enable to analyze the acquired ScanSAR data and generate corresponding images. In this paper, we have developed an efficient ScanSAR processor that can be directly applied to spaceborne ScanSAR mode data. The SPECAN(Spectrum Analysis) algorithm is employed for this purpose and its performance is verified through RADARSAT-1 ScanSAR raw data taken over Korean peninsular. An efficient quick-look processing is carried out to produce a wide-swath SAR image and compared with the conventional RDA processing case.

Analysis of SAR Reduction Methods for Mobile Communication Handsets (이동통신단말기 SAR 저감 방안 분석)

  • 정민석;이범선
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.2
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    • pp.155-163
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    • 2002
  • In this paper, we propose SAR reduction methods based on power conservation relation, After defining SRF(SAR Reduction Factor) for a more quantitative discussion of effective SAR reduction methods, many kinds of simulation have been performed. We compare the SAR by a flip type handset with that of folder type one. It is found that in a typical position of handsets over a human head, the SAR when using the folder type is about 30 % smaller than that when using the flip type. The effects of ferrite material when using flip type handset are shown to be not considerable when using a folder type.

Implementation of SAR Measurement System with Stationary Probes (Probe 고정형 SAR 측정 시스템의 구현)

  • Kim Jeong-Ho;Gimm Youn-Myoung
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.2
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    • pp.221-227
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    • 2006
  • The SAR evaluation system with 9 stationary probes inserted into the object to be surveyed can calculate area SAR value based on the 9 measured electric field data. The results can be acquired in a few seconds by converting obtained area SAR to the volume SAR. The system can be very useful tool in the stages of handset development for mobile communication as well as in the handset production line because of its rapid SAR measurement ability. The validity of the measurement system is checked by showing that the measured SAR values agree well with reference SAR values suggested in the reference documents.

Development and Demonstration of the SAR Processor for Radarsat-1 (Radarsat-1 SAR 신호처리 S/W 개발 및 검증)

  • Koh Bo-Yeon;Kim Man-Jo;Lee Seok-Ho
    • Korean Journal of Remote Sensing
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    • v.21 no.6
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    • pp.483-491
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    • 2005
  • SAR signal processing technique has been considered a crucial technical part in order to generate an image from radar signal data and ADD (Agency for Defense Development) has focused on this area for years to develope our own SAR Processor for various SAR systems (Radarsat, ERS, KOMSAR). In this paper, we investigated major techniques related to generation of SAR images and developed ASPR (ADD SAR Processor for Radarsat) practically using the commercial Radarsat-1 radar signal data (RAW). We demonstrated the performance of the ASPR in comparison with the image generated by MDA and Vexcel's SAR Processor (FOCUS).

Assessment of DEM Generated by Stereo C-band and X-band SAR images using Radargrammetry (Radargrammetry를 이용한 C-밴드 및 X-밴드 SAR 위성영상의 DEM 생성 평가)

  • Song, Yeong Sun;Kim, Gi Hong
    • 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.

Analysis of SAR Processing Performances with FJB Waveforms (FJB 파형을 이용한 SAR 영상 생성 기법 분석)

  • Kim, Eun-Hee;Roh, Ji-Eun;Park, Joon-Yong;Kim, Soo-Bum
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.3
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    • pp.195-207
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    • 2017
  • Recently, the SAR-GMTI mode is becoming increasingly essential in airborne radar systems. While SAR requires wideband waveforms for high resolution imaging, GMTI requires narrowband waveforms for doppler processing, which makes general LFM waveforms difficult to use for SAR-GMTI. This paper analyses the FJB(Frequency Jump Burst) waveform, which is studied for the SAR-GMTI waveform, and presents the method for the pulse compression and SAR image formation using FJB waveforms. Simulation results show that there is little difference in performances between the FJB waveform and the LFM waveform.