• 제목/요약/키워드: Microwave Remote Sensing

검색결과 179건 처리시간 0.028초

구름물리 관측시스템 및 산출물 검정 (Cloud Physics Observation System (CPOS) and Validation of Its Products)

  • 장기호;오성남;정기덕;양하영;이명주;정진임;조요한;김효경;박균명;염성수;차주완
    • 대기
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    • 제17권1호
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    • pp.101-108
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    • 2007
  • To observe and analyze the cloud and fog characteristics, the METeorological Research Institute (METRI) has established the Cloud Physics Observation System (CPOS) by implementing the cloud observation instruments: Forward Scattering Spectrometer Probe (FSSP), PARticle SIze and VELocity (PARSIVEL), Microwave Radiometer (MWR), Micro Rain Radar (MRR), and 3D-AWS at the Daegwallyeong Enhanced Mountain Weather Observation Center. The cloud-related products of CPOS and the validation status for the size distribution of FSSP, the precipitable water of MWR, and the rainfall rate of MRR and PARSIVEL are described.

Integration of ERS-2 SAR and IRS-1 D LISS-III Image Data for Improved Coastal Wetland Mapping of southern India

  • Shanmugam, P.;Ahn, Yu-Hwan;Sanjeevi, S.;Manjunath, A.S.
    • 대한원격탐사학회지
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    • 제19권5호
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    • pp.351-361
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    • 2003
  • As the launches of a series of remote sensing satellites, there are various multiresolution and multi-spectral images available nowadays. This diversity in remotely sensed image data has created a need to be able to integrate data from different sources. The C-band imaging radar of ERS-2 due to its high sensitivity to coastal wetlands holds tremendous potential in mapping and monitoring coastal wetland features. This paper investigates the advantages of using ERS-2 SAR data combined with IRS-ID LISS-3 data for mapping complex coastal wetland features of Tamil Nadu, southern India. We present a methodology in this paper that highlights the mapping potential of different combinations of filtering and integration techniques. The methodology adopted here consists of three major steps as following: (i) speckle noise reduction by comparative performance of different filtering algorithms, (ii) geometric rectification and coregistration, and (iii) application of different integration techniques. The results obtained from the analysis of optical and microwave image data have proved their potential use in improving interpretability of different coastal wetland features of southern India. Based visual and statistical analyzes, this study suggests that brovey transform will perform well in terms of preserving spatial and spectral content of the original image data. It was also realized that speckle filtering is very important before fusing optical and microwave data for mapping coastal mangrove wetland ecosystem.

Study on Thin Sea Ice Thickness using Passive Microwave Brightness Temperature

  • Naoki, Kazuhiro;Ukita, Jinro;Nishio, Fumihiko
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.1015-1018
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    • 2006
  • The use of passive microwave data for estimating sea-ice thickness is limited by strong dependence of emissivity on near-surface brine. However, this particular characteristic becomes a basis for an algorithm to estimate thickness of thin sea-ice if a thickness-salinity-emissivity relationship is established. This study aims at developing an algorithm to estimate sea ice thickness on the basis of this relationship. In order to establish a thickness-salinity-emissivity relationship, we have conducted multi-platform synchronous observations in the Sea of Okhotsk. We note a positive relationship between thickness and brightness temperature. From observations, we also establish an empirical relationship between salinity and emissivity, thus between thickness and brightness temperature. The derived relationship is qualitatively similar to the one based on Hoekstra and Cappillino's formulation. Our results suggest that for thin sea-ice in the winter period there is potential to develop an algorithm to estimate sea-ice thickness.

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NOAA/MUS 자료를 이용한 태풍 중심의 위치및 강도 분석 (The Analysis of Typhoon Center Location and Intensity from NOAA Satellite Microwave Data)

  • 신도식;서애숙;김용상;이미선
    • 대한원격탐사학회지
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    • 제11권2호
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    • pp.29-42
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    • 1995
  • A typhoon center location and its intensity from the 54.96GMz channel of Microwave Sounding Unit(MSU) on board the NOAA satellite is analyzed. NOAA satellite MSU channel 3 data may delineate the development and dissipation of the upper tropospheric warm core associated with a typhoon. The typhoon warm core is related to microwave imagery of 250hPa temperature field (54.96GMz). The typhoon center intensity, surface center pressure and maximum wind speed at the eye well, correlate to horozontal Laplacian of an upper tropospheric temperature field. The typhoon center is found from the analysis of 250hPa temperature field. The excellent correlation is found between the horizontal Laplacian of an tropospheric temperature field and surface maximum wind speed, another correlation is found between the warm temperature anomaly and surface pressure anomaly.

토양 수분 모니터링용 마이크로파 라디오미터 수신기 설계 (Design of a Microwave Radiometer Receiver for Soil Moisture monitoring)

  • 손홍민;박홍균
    • 한국전자통신학회논문지
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    • 제9권2호
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    • pp.173-180
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    • 2014
  • 본 논문은 토양에서 복사되는 마이크로파 대역의 미약한 열잡음 전력을 수신하여 토양 수분 함유량의 변화를 실시간으로 원격모니터링이 가능한 L-Band 마이크로파 라디오미터를 설계하는 내용에 관하여 기술한다. 토양 수분 함유량 0%~50%의 측정범위와 최대 오차 2%의 목표 성능을 달성하기 위해 토양 수분함유량에 따른 토양의 복사특성을 연구 및 목표 사양을 도출하였으며, 이를 바탕으로 도출된 사양을 만족시키는 마이크로파 라디오미터의 수신기를 설계 및 제작하였다. 제작된 수신기는 주파수 1390MHz, 대역폭 40MHz으로 50dB의 시스템 이득과 1.54dB의 NF를 가지며, 최대 0.313K, 평균 0.19K의 수신감도를 갖는다.

해남 플럭스 타워 지점에서의 Advanced Microwave Scanning Radiometer E 토양수분자료의 검증 (Advanced Microwave Scanning Radiometer E Soil Moisture Evaluation for Haenam Flux Monitoring Network Site)

  • 허유미;최민하
    • 대한원격탐사학회지
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    • 제27권2호
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    • pp.131-140
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    • 2011
  • 본 연구에서는 원격탐사자료인 Advanced Microwave Scanning Radiometer E (AMSR-E) 토양수분자료의 시간적 변통성 검증을 위해 해남 플럭스 지점에서 관측된 2년간의 (2004년과 2006년) 토양수분자료를 이용하였다. 지상관측 토양수분자료에 비해 상대적으로 큰 공간해상도를 가진 원격탐사자료(AMSR-E)는 2년간의 비교/검증에서 지상관측토양수분자료와 시간적 상관성이 있는 것으로 파악되었으며, 차후에 보다 다양한 식생조건과 현장조건에서 심도 있는 검증연구가 이루어져야 할 것으로 판단된다. 이를 위해서는 보다 다양한 지역에서 현장측정이 이루어져야할 것으로 사료된다. 이를 통하여 보다 정확한 비교/검증 연구가 수행된다면, 원격탐사 토양수분자료의 활용성을 기대할 수 있으며 또한 수문기상학적 관점에서 지표면 대기의 상호작용에 대한 올바른 이해를 향상시킬 수 있을 것으로 판단된다.

CORRECTION OF THE EFFECT OF RELATIVE WIND DIRECTION ON WIND SPEED DERIVED BY ADVANCED MICROWAVE SCANNING RADIOMETER

  • Konda, Masanori;Shibata, Akira
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.386-389
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    • 2006
  • The sea surface wind speed (SSWS) derived by microwave radiometer can be contaminated by change of microwave brightness temperature owing to the angle between the sensor azimuth and the wind direction (Relative Wind Direction). We attempt to correct the contamination to the SSWS derived by Advanced Microwave Scanning Radiometer (AMSR) on Advanced Earth Observing Satellite II (ADEOS-II), by applying the method proposed by Konda and Shibata (2004). The improvement of accuracy of the SSWS estimation amounts to roughly 60% of the error caused by the RWD effect.

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Estimation of rice growth parameters by X-band radar backscattering data

  • Kim, Yi-Hyun;Hong, Suk-Young;Lee, Hoon-Yol
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.324-327
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    • 2008
  • Microwave remote sensing has great potential, especially in monsoon Asia, since optical observations are often hampered by cloudy conditions. The radar backscattering characteristics of rice crop were investigated with a ground-based automatic scatterometer system. The system was installed inside a shelter in an experimental paddy field at the National Institute of Agricultural Science and Technology (NIAST) before transplanting. The rice cultivar was a kind of Japonica type, called Chuchung. The scatterometer system consists of X-band antennas, HP8720D vector network analyzer, RF cables, and a personal computer that controls frequency, polarization and data storage. This system automatically measures fully-polarimatric backscattering coefficients of rice crop every 10 minutes, accompanied by a digital camera that takes pictures in a fixed position with the same interval. The backscattering coefficients were calculated by applying a radar equation. Plant variables, such as leaf area index (LAI), biomass, plant height and weather conditions were measured periodically throughout the rice growth season. We have performed polarimetric decomposition of paddy data such as single, double and volume scattering to extract the scattering information effectively. We investigated the relationships between backscattering coefficients and the plant variables.

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Development of Snowfall Retrieval Algorithm by Combining Measurements from CloudSat, AQUA and NOAA Satellites for the Korean Peninsula

  • Kim, Young-Seup;Kim, Na-Ri;Park, Kyung-Won
    • 대한원격탐사학회지
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    • 제27권3호
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    • pp.277-288
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    • 2011
  • Cloudsat satellite data is sensitive to snowfall and collected during each month beginning with Dec 2007 and ending Feb 2008. In this study, we attempt to develop a snowfall retrieval algorithm using a combination of radiometer and cloud radar data. We trained data from the relation between brightness temperature measurements from NOAA's Advanced Microwave Sounder Unit-B(AMSU-B) and the radar reflectivity of the 2B-GEOPROF product from W-band(94 GHz) cloud radar onboard Cloudsat and applied it to the Korea peninsula. We use a principal components analysis to quantify the variations that are the result of the radiometric signatures of snowfall from those of the surface. Finally, we quantify the correlation between the higher principal component (orthogonal to surface variability) of the microwave radiances and the precipitation-sensitive CloudSat radar reflectivities. This work summarizes the results of applying this approach to observations over the East Sea during Feb. 2008. The retrieved data show reasonable estimation for snowfall rate compared with Cloudsat vertical image.