• 제목/요약/키워드: microwave synthetic system

검색결과 21건 처리시간 0.028초

마이크로파 에너지에 의해 결정 크기가 조절된 유기 안료의 합성 (The Synthesis of Crystalline-Size Controlled Organic Pigment by Microwave Energy)

  • 정기석;고진필;박상보;박찬영;민성기;권종호;오인환;박성수
    • 폴리머
    • /
    • 제25권5호
    • /
    • pp.609-616
    • /
    • 2001
  • 본 연구에서는 copper phthalocyanine (CUPc)을 높은 합성 수율로서 성공적으로 합성시킴에 따라 용매를 사용하는 고분자의 합성 분야에 마이크로파 기술의 응용 가능성을 제시하고자 하였다. 가정용 전자레인지의 용기를 개조시키고 마이크로파 출력 조절기를 부착시키는 방법으로 본 실험에 사용되는 가변식 마이크로파 합성 장치를 자체 제작하였다. 화학 분석법, X선 회절장치(XRD), 주사형 전자현미경 (SEM) 및 입도 분석법 (PSA)을 이용하여 재래식 열 공정 및 마이크로파 공정을 사용하여 여러 조건하에서 합성된 시료들의 특성을 비교 분석하였다.

  • PDF

Some Further Consideration for the Image Retrieving of Synthetic Aperture Radiometer

  • Liu, Hao;Wu, Ji;Wu, Qiong
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.1349-1351
    • /
    • 2003
  • In this paper, theoretical channels model of Synthetic Aperture Radiometer is presented. Based on this model, how amplitude imbalance, phase imbalance and mutual coupling between the different channels effect brightness temperature image retrieving is analyzed. The computer simulation results are also presented to find out the cause of the along-track streaks usually appeared in the retrieved brightness temperature image. In addition, a new system calibration approach is introduced to solve this problem.

  • PDF

SAR를 이용한 다층 유전체의 비파괴 검사 (Nondestructive Inspecting for Multilayer Dielectric Material using Synthetic Aperture Radar)

  • 김성덕
    • 전기전자학회논문지
    • /
    • 제20권4호
    • /
    • pp.424-427
    • /
    • 2016
  • 이 논문에서는 FRP(Fiber Reinforced Polymer)의 내부 결함이나 물리적 손상을 검출하기 위하여 SAR(Synthetic Aperture Radar)를 이용한 마이크로파 비파괴 검사법(Microwave Nondestructive Inspecting)을 제안한다. 전파가 다층 유전체인 FRP에 수직으로 입사되면 계면이나 횡축 균열과 같은 결함에 좋은 반응을 나타낸다. 이때 반사파로부터 계면 깊이나 결함 위치를 SAR 이미지 기법으로 결함을 형상화할 수 있다. 그 결과, SAR 시스템으로 FRP 복합 소재 내부 결함들의 종류, 크기나 위치를 효율적으로 진단할 수 있음을 확인하였다.

THE DEVELOPMENT OF CIRCULARLY POLARIZED SYNTHETIC APERTURE RADAR SENSOR MOUNTED ON UNMANNED AERIAL VEHICLE

  • Baharuddin, Merna;Akbar, Prilando Rizki;Sumantyo, Josaphat Tetuko Sri;Kuze, Hiroaki
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
    • /
    • pp.441-444
    • /
    • 2008
  • This paper describes the development of a circularly polarized microstrip antenna, as a part of the Circularly Polarized Synthetic Aperture Radar (CP-SAR) sensor which is currently under developed at the Microwave Remote Sensing Laboratory (MRSL) in Chiba University. CP-SAR is a new type of sensor developed for the purpose of remote sensing. With this sensor, lower-noise data/image will be obtained due to the absence of depolarization problems from propagation encounter in linearly polarized synthetic aperture radar. As well the data/images obtained will be investigated as the Axial Ratio Image (ARI), which is a new data that hopefully will reveal unique various backscattering characteristics. The sensor will be mounted on an Unmanned Aerial Vehicle (UAV) which will be aimed for fundamental research and applications. The microstrip antenna works in the frequency of 1.27 GHz (L-Band). The microstrip antenna utilized the proximity-coupled method of feeding. Initially, the optimization process of the single patch antenna design involving modifying the microstrip line feed to yield a high gain (above 5 dBi) and low return loss (below -10 dB). A minimum of 10 MHz bandwidth is targeted at below 3 dB of Axial Ratio for the circularly polarized antenna. A planar array from the single patch is formed next. Consideration for the array design is the beam radiation pattern in the azimuth and elevation plane which is specified based on the electrical and mechanical constraints of the UAV CP-SAR system. This research will contribute in the field of radar for remote sensing technology. The potential application is for landcover, disaster monitoring, snow cover, and oceanography mapping.

  • PDF

Microwave Radiometer for Space Science and DREAM Mission of STSAT-2

  • Kim, Y.H.
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
    • /
    • 한국우주과학회 2008년도 한국우주과학회보 제17권2호
    • /
    • pp.31.4-32
    • /
    • 2008
  • The microwave instruments are used many areas of the space remote sensing and space science applications. The imaging radar of synthetic aperture radar (SAR) is well known microwave radar sensor for earth surface and ocean research. Unlike radar, microwave radiometer is passive instrument and it measures the emission energy of target, i.e. brightness temperature BT, from earth surface and atmosphere. From measured BT, the geophysical data like cloud liquid water, water vapor, sea surface temperature, surface permittivity can be retrieved. In this paper, the radiometer characteristics, system configuration and principle of BT measurement are described. Also the radiometer instruments TRMM, GPM, SMOS for earth climate, and ocean salinity research are introduce. As first korean microwave payload on STSAT-2, the DREAM (Dual-channels Radiometer for Earth and Atmosphere Monitoring) is described the mission, system configuration and operation plan for life time of two years. The main issues of DREAM unlike other spaceborne radiometers, will be addressed. The calibration is the one of main issues of DREAM mission and how it contribute on the space borne radiometer. In conclusion, the radiometer instrument to space science application will be considered.

  • PDF

Microwave Remote Sensing System Development in MACRES

  • Mahmood, K.A.;Ali, A.;Yusof, S.;Ahmad, Z.;Jamil, H.;Ibrahim, N.;Aziz, H.;Abu Bakar, S.B.
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.1012-1014
    • /
    • 2003
  • Since it's establishment Malaysian Center for Remote Sensing (MACRES) has focused on the measurements from airborne and space borne remote sensors. In the year 1999 MACRES in collaboration with Multimedia University Malaysia (MMU) began developing it's own remote sensing sensors to meet Malaysian Remote Sensing needs. MACRES adopted a very systematic approached to the development of these microwave sensors. Starting from non-imaging ground base microwave remote sensing sensors MACRES is now well into developing it's first Airborne Synthetic Aperture Radar. With the capability of developing it's own sensors MACRES will profit more on the microwave remote sensing application research. This paper will demonstrate MACRES capability in developing Microwave Remote Sensing Sensors to meet Malaysian remote sensing society needs.

  • PDF

SAR Remote Sensing Technology Development and Application in China

  • Jing, Li
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2002년도 Proceedings of International Symposium on Remote Sensing
    • /
    • pp.448-453
    • /
    • 2002
  • Remote sensing technology is one of the most powerful tools for human to know the nature and their living environment. However, before microwave remote sensing was developed and applied, remote sensing application was limited strongly by weather and time. Microwave remote sensing technology solves the problem. It makes us to have the capability to acquire information at all time of the day and under all weather condition, and make remote sensing technology be used in more wider area. Microwave remote sensing system include mainly Synthetic Aperture Radar (SAR), Microwave Radiometer, Microwave Scatterometer, and Altimeter (ALT). As SAR can acquire image whose spatial resolution is similar with visible and infrared image, it is paying much attention to and playing a more and more important role in earth observation. In recent year, the development of new SAR technology (multi-band and multi-polarization technology, InSAR technology, D-InSAR technology, and so on) makes SAR remote sensing go to an new stage, and its application area become more and more widely. The first Synthetic Aperture Radar (SAR) in the world appeared in 1960. After that, SAR and its application all developed very fast. Some radar satellites launched and run (include Seasat-A in 1978, ERS-1 in 1991, JERS-1 in 1992, Radarsat in 1995, and so on) promote SAR research and application in world greatly. China began to develop its SAR sensor and research SAR application in 1970s. After more than 30 years' research, it get some important development in sensor development data processing method, and application. Some operational systems have been used and play an important role. This paper will introduce the development of SAR technology and its application in China.

  • PDF

A Simple Microwave Backscattering Model for Vegetation Canopies

  • Oh Yisok;Hong Jin-Young;Lee Sung-Hwa
    • Journal of electromagnetic engineering and science
    • /
    • 제5권4호
    • /
    • pp.183-188
    • /
    • 2005
  • A simple microwave backscattering model for vegetation canopies on earth surfaces is developed in this study. A natural earth surface is modeled as a two-layer structure comprising a vegetation layer and a ground layer. This scattering model includes various scattering mechanisms up to the first-order multiple scattering( double-bounce scattering). Radar backscatter from ground surface has been modeled by the polarimetric semi-empirical model (PSEM), while the backscatter from the vegetation layer modeled by the vector radiative transfer model. The vegetation layer is modeled by random distribution of mixed scattering particles, such as leaves, branches and trunks. The number of input parameters has been minimized to simplify the scattering model. The computation results are compared with the experimental measurements, which were obtained by ground-based scatterometers and NASA/JPL air-borne synthetic aperture radar(SAR) system. It was found that the scattering model agrees well with the experimental data, even though the model used only ten input parameters.

복합재료 하니콤 샌드위치 판넬을 이용한 SAR 시스템용 마이크로스트립 안테나 개발 (Microstrip Antenna for SAR Applications with Microwave Composite Laminates and Honeycomb Cores)

  • 유치상;이라미;황운봉;박현철;박위상
    • 한국복합재료학회:학술대회논문집
    • /
    • 한국복합재료학회 2000년도 추계학술발표대회 논문집
    • /
    • pp.195-198
    • /
    • 2000
  • Microstrip antenna for SAR applications is designed with microwave composite laminates and Nomex honeycomb cores, which becomes an aircraft's structural panel. This study demonstrated fabrication, design procedures and structural and electrical performances of complex antenna system presented. For validating structural rigidity, 3-point bending test is performed, and simulation results for the complex antenna array are compared with measurements for its electrical performance. The results show that this antenna system can be applied in dual polarized synthetic aperture radar and has a good flexural stiffness with comparison of previous sandwich constructions.

  • PDF

Quality Analysis of SAR Image

  • Lee, Young-Ran;Kwak, Sung-Hee;Shin, Dong-Seok;Park, Won-Kyu
    • 대한원격탐사학회:학술대회논문집
    • /
    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
    • /
    • pp.628-630
    • /
    • 2003
  • Synthetic Aperture Radar(SAR) is an active microwave instrument that performs high-resolution observation under almost all weather condition. Research and algorithms have been proposed to process radar signal and to increase the quality of SAR products. In fact, many complicated steps are involved in order to generate a SAR image product. The purpose of this paper is to derive quality assessment procedures and define important test parameters in each procedure inside a SAR processor. Thus those test parameter values indicate the quality of SAR image products and verify the processor's performance. Moreover, required procedures to correct and handle errors which are indicated during the assessment are also presented.

  • PDF