• Title/Summary/Keyword: Split-window

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RETRIEVAL OF LAND SURFACE TEMPERATURE FROM MTSAT-1R

  • Kwak, Seo-Youn;Suh, Myoung-Seok;Kang, Jeon-Ho;Kwak, Chong-Heum;Kim, Chan-Soo
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.250-252
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    • 2006
  • The land surface temperature (LST) can be defined as a weighted average temperature of components which constitute a pixel. The coefficients of split-window algorithm for MTSAT-1R were obtained by means of a statistical regression analysis from radiative transfer simulations using MODTRAN 4.0 for a wide range of atmospheric, satellite viewing angle (SVA) and lapse rate conditions. 6 types of atmospheric profile data imbedded in the MODTRAN 4 are used for the radiative transfer simulations. The RMSE is clearly larger on warm and humid profiles than cold and dry profiles, especially when the satellite viewing angle and lapse rate are large. The derivation of LST equations according to the atmospheric profiles clearly decreased the RMSE without regard to the SVA and lapse rate. The bias and RMSE are decreased as the more controls factors included. This preliminary result indicates that the characteristics of atmosphere, SVA and lapse rate should be included in the LST equation.

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Enhancement of Frequency Lines of Acoustic Signature in Vernier Analysis Using the Autocorrelation-based Postprocessing (Vernier 신호 분석에서 자기상관함수 기반의 후처리를 이용한 주파수선 음향징표 특징 강화)

  • Lee, Jungho;Bae, Keunsung
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.3
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    • pp.546-555
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    • 2013
  • In this paper, we propose a novel method to enhance the harmonic components from the frequency lines of the passive sonar signals. For this, we first separate the stable frequency lines from unstable ones using mean and difference of spectral bins in the vernier analysis. Then we emphasize the harmonic components using autocorrelation-based postprocessing, and enhance them by reducing the background noise with the split-window two pass mean algorithm. Experimental results for real underwater acoustic data are presented with our discussions.

Retrieval of land Surface Temperature from MTSAT-1R

  • Kwak, Seo-Youn;Suh, Myoung-Seok;Kang, Jeon-Ho;Kwak, Chong-Heum;Kim, Chan-Soo
    • Korean Journal of Remote Sensing
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    • v.22 no.5
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    • pp.385-388
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    • 2006
  • The land surface temperature (LST) can be defined as a weighted average temperature of components which constitute a pixel. The coefficients of split-window algorithm for MTSAT-1R were obtained by means of a statistical regression analysis from radiative transfer simulations using MODTRAN 4.0 for a wide range of atmospheric, satellite viewing angle (SVA) and lapse rate conditions. 6 types of atmospheric profile data imbedded in the MODTRAN 4 are used for the radiative transfer simulations. The RMSE is clearly larger on warm and humid profiles than cold and dry profiles, especially when the satellite viewing angle and lapse rate are large. The derivation of LST equations according to the atmospheric profiles clearly decreased the RMSE without regard to the SVA and lapse rate. The bias and RMSE are decreased as the more controls factors included. This preliminary result indicates that the characteristics of atmosphere, SVA and lapse rate should be included in the LST equation.

A Comparative Study of Algorithms for Estimating Land Surface Temperature from MODIS Data

  • Suh, Myoung-Seok;Kim, So-Hee;Kang, Jeon-Ho
    • Korean Journal of Remote Sensing
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    • v.24 no.1
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    • pp.65-78
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    • 2008
  • This study compares the relative accuracy and consistency of four split-window land surface temperature (LST) algorithms (Becker and Li, Kerr et ai., Price, Ulivieri et al.) using 24 sets of Terra (Aqua)/Moderate Resolution Imaging Spectroradiometer (MODIS) data, observed ground grass temperature and air temperature over South Korea. The effective spectral emissivities of two thermal infrared bands have been retrieved by vegetation coverage method using the normalized difference vegetation index. The intercomparison results among the four LST algorithms show that the three algorithms (Becker-Li, Price, and Ulivieri et al.) show very similar performances. The LST estimated by the Becker and Li's algorithm is the highest, whereas that by the Kerr et al.'s algorithm is the lowest without regard to the geographic locations and seasons. The performance of four LST algorithms is significantly better during cold season (night) than warm season (day). And the LST derived from Terra/MODIS is closer to the observed LST than that of Aqua/MODIS. In general, the performances of Becker-Li and Ulivieri et al algorithms are systematically better than the others without regard to the day/night, seasons, and satellites. And the root mean square error and bias of Ulivieri et al. algorithm are consistently less than that of Becker-Li for the four seasons.

Algorithm to prevent Block Discontinuity by Overlapped Block and Manning Window (중첩 기반 연산과 Hanning Window를 이용한 블록 불연속 노이즈 방지 알고리즘)

  • Kim, Joo-Hyun;Jang, Won-Woo;Park, Jung-Hwan;Yang, Hoon-Gee;Kang, Bong-Soon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.9
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    • pp.1650-1657
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    • 2007
  • In this paper, we propose an Overlapped Block and an Hanning Window to prevent a Block Discontinuity when we use an algorithm to eliminate ringing artifact which is based on a block structure. The algorithm to eliminate ringing artifact operates with a block structure and 24-RGB data and is based on a modified K-means algorithm. The proposed overlapped block method is piled up one on another per an half of the size of unit-block when an input image is split into several unit-blocks. Therefore, we define a data unit as the unit-block of the block size, $16{\times}16$ pixels. We reconstruct the processed data units into the original form of input image by using an isotropic form of Hanning Window. Finally, in order to evaluate the performance of the abovementioned algorithms, we compare three image, an input image with ringing artifact, an image result obtained by conventional method (non-overlapped), and an image result obtained the proposed method.

Development of an User-Friendly Designed Characteristics Analysis Program of Permanent-Split Capacitor Single-Phase Induction Motor (사용자 편의성이 향상된 콘덴서 구동형 단상 유도전동기 특성해석 프로그램의 개발)

  • Jung, In-Soung;Kim, Young-Jung;Sung, Ha-Gyeong
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.884-885
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    • 2007
  • This paper presents an window based user-friendly designed characteristics analysis program of permanent-split capacitor single-phase induction motor. For the analysis, equivalent magnetic circuit and symmetrical coordinate method are used. The saturation effect and iron loss of stator and rotor core are considered. The analysis program is made to GUI type which can be used easily by many elementary designer. The accuracy of analysis is verified by comparison with experimental results.

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Image Processed Tracking System of Multiple Moving Objects Based on Kalman Filter

  • Kim, Sang-Bong;Kim, Dong-Kyu;Kim, Hak-Kyeong
    • Journal of Mechanical Science and Technology
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    • v.16 no.4
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    • pp.427-435
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    • 2002
  • This paper presents a development result for image processed tracking system of multiple moving objects based on Kalman filter and a simple window tracking method. The proposed algorithm of foreground detection and background adaptation (FDBA) is composed of three modules: a block checking module(BCM), an object movement prediction module(OMPM), and an adaptive background estimation module (ABEM). The BCM is processed for checking the existence of objects. To speed up the image processing time and to precisely track multiple objects under the object's mergence, a concept of a simple window tracking method is adopted in the OMPM. The ABEM separates the foreground from the background in the reset simple tracking window in the OMPM. It is shown through experimental results that the proposed FDBA algorithm is robustly adaptable to the background variation in a short processing time. Furthermore, it is shown that the proposed method can solve the problems of mergence, cross and split that are brought up in the case of tracking multiple moving objects.

Estimation of the Temporal and Spatial Variation of Surface Temperature Distribution in the Korean Peninsula using NOAA/AVHRR Data (NOAA/AVHRR 위성자료를 이용한 한반도 표면온도의 시공간적 변동 추정)

  • Suh, Young-Sang;Lee, Gi-Chul;Lee, Na-Kyung;Jo, Myung-Hee
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.3
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    • pp.150-160
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    • 2005
  • In this study, the spatiotemporal surface temperature changes were analyzed in the Korean peninsula. The surface temperature variation was estimated using the split window method and NOAA/AVHRR data in 1991, 1995 and 2000. The ranges of differences in temperature between day time and night time were $3-15^{\circ}C$ around the peninsula. The differences in seasonal variations and yearly fluctuations in big cities were lower than those in rural areas and showed clearly the effects of the urbanization. The characteristics of urban heat affects were further determined based on the day and night time temperature comparison on Busan metropolitan area between these periods. Finally, the future use of this technology was suggested for the urban environmental planning.

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DEVELOPMENT AND VALIDATION OF LAND SURFACE TEMPERATURE RETRIEVAL ALGORITHM FROM MTSAT-1R DATA

  • Hong, Ki-Ok;Kang, Jeon-Ho;Suh, Myoung-Seok
    • Proceedings of the KSRS Conference
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    • 2008.10a
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    • pp.293-296
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    • 2008
  • Land surface Temperature (LST) is a very useful surface parameter for the wide range of applications, such as agriculture, numerical and climate modelling community. Whereas operational observation of LST is far from the needs of application community in the spatial Itemporal resolution and accuracy. So, we developed split-window type LST retrieval algorithm to estimate the LST from MTSAT-IR data. The coefficients of split-window algorithm were obtained by means of a statistical regression analysis from the radiative transfer simulations using MODTRAN 4 for wide range of atmospheric profiles, satellite zenith angle and lapse rate conditions including the surface inversions. The sensitivity analysis showed that the LST algorithm reproduces the LST with a reasonable quality. However, the LST algorithm overestimates and underestimates for the strong surface inversion and superadiabatic conditions especially for the warm temperature, respectively. And the performance of LST algorithms is superior when satellite zenith angle is small. The accuracy of the retrieved LST has been evaluated with the Moderate Resolution Imaging Spectroradiometer (MODIS) LST data. The validation results showed that the correlation coefficients and RMSE are about 0.83${\sim}$0.98 and 1.38${\sim}$4.06, respectively. And the quality of LST is significantly better during night and winter time than during day and summer. The validation results showed that the LST retrieval algorithm could be used for the operational retrieval of LST from MTSAT-IR and COMS(Communication, Ocean and Meteorological Satellite) data with some modifications.

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Regional optimization of an atmospheric correction algorithm for the retrieval of sea surface temperature from Korean Sea area using NOAA/AVHRR data (NOAA/AVHRR 자료를 이용한 한반도 주변해역에서의 해수면온도 추출을 위한 지역적인 대기보정 알고리즘의 적용)

  • Yoon, Suk;Ryu, Joo-Hyung;Ahn, Yu-Hwan;Won, Joong-Sun
    • Proceedings of the KSRS Conference
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    • 2008.03a
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    • pp.164-169
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    • 2008
  • 한국해양연구원에서 수신한 자료인 NOAA 12, 16, 17, 18호등의 Advanced Very High Resolution Radiometer(AVHRR) 센서자료와 국립조사원에서 제공하는 해양실측자료인 정선 관측 자료를 이용하여 두 가지의 알고리즘 적용을 통하여 비교 및 분석을 해보고자 한다. 연구 기간은 2006년 1월부터 4월 자료 중 구름의 영향이 없는 영상에서 실측자료와 동일한 날짜 총 107개의 정점 값을 추출하였다. 위성 자료에서 해수면 온도 추출방법은 split window 방법으로, 고정계수 값을 사용하는 linear algorithm(MCSST), nonlinear algorithm(NLMCSST)을 이용하였다. 연구 지역은 동해, 황해, 남해 지역에 대한 지역별로 두 알고리즘을 비교 적용하였다. 전 해역의 값을 이용하여 위성자료와 실측자료를 비교 분석한 결과 linear algorithm방법의 평균 오차 값은 0.71$^{\circ}C$이고 상관도는 1%이고, nonlinear 방법의 오차 값은 0.35$^{\circ}C$ 상관도는 1%로 나타났다. 해역별로는 linear한 알고리즘을 적용하여 동해는(ES)는 R=1, 오차 값은 0.37$^{\circ}C$ 황해(YS)는 R=0.99 오차 값은 0.125$^{\circ}C$ 남해(SS)는 R=0.99 오차 값은 1.2$^{\circ}C$보였다. nonlinear한 알고리즘을 적용하여 동해는(ES)는 R=1, 오차 값은 0.4$^{\circ}C$ 황해(YS)는 R=0.99 오차 값은 0.13$^{\circ}C$ 남해(SS)는 R=0.99 오차 값은 0.82$^{\circ}C$의 결과를 보여 주었다. 동해와 황해지역은 linear한 알고리즘을 적용한 결과가 실측자료와의 오차 값이 작았고, 남해지역은 linear한 알고리즘을 적용한 결과보다 nonlinear 알고리즘을 적용한 것이 작은 오차 값을 보여주었다. 이는 남해 해역의 자료가 대기의 상태나 다른 영향을 받아 해수면온도 값이 추정된 것으로 보여 진다. 해역별로 최적화된 알고리즘을 적용하여 해수면온도의 산출을 통해서 위성자료의 정밀도 지구환경변화 모니터링 등 많은 연구에 위성자료의 활용이 증대될 것으로 기대한다.

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