• 제목/요약/키워드: remote sensing signal

검색결과 264건 처리시간 0.032초

원격감지 성페로몬트랩을 이용한 멸강나방(Mythimna separata) 성충 예찰 (Monitoring of Mythimna separata Adults by Using a Remote-sensing Sex Pheromone Trap)

  • 정진교;서보윤;조점래;김용
    • 한국응용곤충학회지
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    • 제52권4호
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    • pp.341-348
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    • 2013
  • 비래해충인 멸강나방 성충의 발생을 실시간으로 예찰하기 위하여, 성페로몬 트랩에 원격감지장치를 설치한 트랩의 운용 효율성을 검정하였다. 원격감지트랩은 콘트랩 기반에 곤충의 유입을 광차단으로 감지하는 센서부, 신호전송부, 태양열기반의 전력공급부, 트랩 지지대, 웹페이지 기반의 자료수집부로 구성되었다. 연구과정에서 멸강나방 수컷 성충의 밤 시간대 포획의 일일주기성을 이용한 신호감지 시간대 축소, 신호발생 프로그램 조절, 1시간 간격의 전송간격, 신호전송 프로그램 변형 등을 통해 포획 나방수와 감지신호 발생 수의 격차를 줄여 최종적으로 신호 정확도를 92% 이상으로 개선하였다. 또한 실제 멸강나방 성충의 발생양상과 원격감지트랩에서의 신호 발생양상의 상관계수가 0.98이상으로 원격감지트랩에서의 신호 발생이 멸강나방 발생 양상을 정확하게 반영하는 것으로 나타났다. 2011~2012년 멸강나방은 연중 여러 번 발생되는 것이 관찰되었는데, 모두 짧은 기간 동안 발생되어 가파른 피크가 특징이었다.

VALIDITY OF NDVI-BASED BIOPHYSICAL PARAMETERS FOR ECOSYSTEM MODELS

  • Lee, Kyu-Sung;Jang, Ki-Chang;Kim, Tae-Geun;Lee, Seung-Ho;Cho, Hyun-Guk
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.543-546
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    • 2006
  • NDVI has been very frequently used to estimate several biophysical parameters that are required for ecosystem models. Leaf area index (LAI), canopy closure, and biomass are among those biophysical parameters that are estimated by empirical relationship with NDVI. However, the type of remote sensing signals (raw DN value, at-sensor radiance, atmospherically corrected reflectance) used can vary the calculation of NDVI. In this study, we tried to attempt to compare the influence of NDVI linked with forest LAI for the watershed-scale ecosystem models to estimate evapotranspiration. Landsat ETM+ data were used to obtain various NDVI values over the study area in central Korea. The NDVI-based LAI and the resultant evapotranspiration estimation were greatly varied by the remote sensing signal applied.

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A Mini Review of Recent Advances in Optical Pressure Sensor

  • Gihun Lee;Hyunjin Kim;Inkyu Park
    • 센서학회지
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    • 제32권1호
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    • pp.22-30
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    • 2023
  • Innovative and advanced technologies, including robots, augmented reality, virtual reality, the Internet of Things, and wearable medical equipment, have largely emerged as a result of the rapid evolution of modern society. For these applications, pressure monitoring is essential and pressure sensors have attracted considerable interest. To improve the sensor performance, several new designs of pressure sensors have been researched based on resistive, capacitive, piezoelectric, optical, and triboelectric types. In particular, optical pressure sensors have been actively studied owing to their advantages, such as robustness to noise and remote sensing capability. Herein, a review of recent research on optical pressure sensors with self-powered sensing, remote sensing, high spatial resolution, and multimodal sensing capabilities is presented from the viewpoints of design, fabrication, and signal processing.

원격탐사 영상의 감독분류를 위한 개선된 하이브리드 c-Means 군집화 알고리즘 (Improved Algorithm of Hybrid c-Means Clustering for Supervised Classification of Remote Sensing Images)

  • 전영준;김진일
    • 융합신호처리학회논문지
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    • 제8권3호
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    • pp.185-191
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    • 2007
  • 윈격탐사 영상은 파장대에 따라 나누어진 여러 개의 밴드로부터 수집된 다중분광 이미지 데이터이다. 위성영상 분류는 원격탐사 처리 과정에 있어서 가장 중요한 분석 기법으로써 영상을 구성하는 각각의 화소들 중 비슷한 분광 특성을 갖는 것끼리 집단화시켜주는 방법이다. 본 논문에서는 PFCM 알고리즘을 응용한 원격탐사 영상의 패턴분류 방법에 관하여 연구하였다. PFCM 알고리즘은 각 데이터와 특정 클러스터 중심과의 거리에 대한 소속정도를 고려한 FCM 클러스터링 알고리즘과 데이터와 해당 클러스터 중심과의 거리에 의존하여 패턴의 전형성(typicality)을 고려한 PCM 클러스터링 알고리즘을 결합한 방법이다. 본 연구에서는 분류 항목별 학습데이터를 선정한 후 이를 PFCM 알고리즘에 적용하여 감독분류를 수행하였다. Landsat TM과 IKONOS 원격탐사 위성영상을 이용하여 PFCM 알고리즘의 적용성을 검증하였다. PFCM 알고리즘을 이용한 감독분류는 PCM, FCM 분류방법보다 좋은 결과를 보여주었으며, 또한 전통적인 분류방법인 최대우도분류보다도 정확도가 더 높은 결과를 보여주었다.

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Characteristics of Chlorophyll a Absorption in Case 2 Water for Using Remote Sensing Data

  • Islam, Monirul;Sado, Kimiteru
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1-3
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    • 2003
  • In this study, spectroradiometer data were coupled with fluorometer data to find out the best suited bands ratio to monitor the chlorophyll a concentration for inland water. Remote sensing reflectance measurements were used to evaluate the performance of several default ocean color chlorophyll algorithms for SeaWiFS data. This study shows that the chlorophyll a concentration from fluorometer and reflectance from spectroradiometer lies in exploiting the signal provided by the chlorophyll a red absorption peak near 670nm. Two-band ratio based on a ratio of reflectance 670 and 700nm provided a good correlation for a linear model, compare with blue-green two band ratio.

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Adaptive Reconstruction Of AVHRR NVI Sequential Imagery off Korean Peninsula

  • Lee, Sang-Hoon;Kim, Kyung-Sook
    • 대한원격탐사학회지
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    • 제10권2호
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    • pp.63-82
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    • 1994
  • Multitemporal analysis with remotely sensed data is complicated by numerous intervening factors, including atmospheric attenuation and occurrence of clouds that obscure the relationship between ground and satellite observed spectral measurements. A reconstruction system was developed to increase the discrimination capability for imagery that has been modified by residual dffects resulting from imperfect sensing of the target and by atmospheric attenuation of the signal. Utilizing temporal information based on an adaptive timporal filter, it recovers missing measurements resulting from cloud cover and sensor noise and enhances the imagery. The temporal filter effectively tracks a systematic trend in remote sensing data by using a polynomial model. The reconstruction system were applied to the AVHRR data collected over Korean Peninsula. The results show that missing measurements are typically recovered successfully and the temporal trend in vegetation change is exposed clearly in the reconstructed series.

Detection of Red Tides by IRS/OCM Imagery

  • Kang, Y.Q.;Suh, Y.S.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.697-699
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    • 2003
  • We present a simple algorithm for detection of red patches by remote sensing in coastal waters of Korea. The red tide patches can by identified by the relative intensity of red band signal with respect to the blue-green background signal, provided the radiometric signals only in the sea area are properly stretched. We tested our algorithm by Ocean COlor Monitor(OCM) data of Indian Satellite IRS-P4, which has been received from 2001 by National Fisheries Research and Development Institute of Korea. A comparison of our results with observation shows that the locations of red tides derived from remote sending imagery by our algorithm are in accordance with observations.

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Open Loop Technique in FORMOSAT-3/COSMIC mission

  • Yeh, Wen-Hao;Chiu, Tsen-Chieh;Liou, Yuei-An;Huang, Cheng-Yung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.394-396
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    • 2007
  • Radio occultation (RO) technique has been used in planetary science since 1960s. When signal goes through atmosphere, it is refracted due to the gradient of atmospheric refractivity. In 1995, the first low earth orbit (LEO) satellite, MicroLab-1, was launched to conduct RO mission. It receives the signal from global positioning system (GPS) satellites. After MicroLab-1, other RO missions, such as CHAMP, SAC-C, and GRACE, are executed in several years later. In 2006, Taiwan launched six LEO satellites for RO mission. The mission name is Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC). Under some abnormal situations, multipath and strong fluctuation in phase and amplitude of the signal appear in moist troposphere. Therefore, open loop (OL) technique has been applied to replace traditional phase lock loop (PLL) technique. In this paper, we will summarize the retrieval processing procedure and discuss the advantages and disadvantages of OL technique.

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RF Power Detector for Location Sensing

  • Kim, Myung-Sik;Kubo, Takashi;Chong, Nak-Young
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.1771-1774
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    • 2005
  • Recently, RFID has become popular in the field of remote sensing applications. Location awareness is one of the most important keys to deploying RFID for advanced object tracking. Generally, multiple reference RF stations or additional sensors are used for the location sensing with RFID, but, particularly in indoor environments, spatial layout and cost problems limit the applicability of those approaches. In this paper, we propose a novel method for location sensing with active RFID systems not requiring the need for reference stations or additional sensors. The system triangulates the position of RF signal source using the signal pattern of the loop antenna connected to the power detector. The power detector consists of a signal strength detector and a signal analysis unit. The signal analysis unit indicates the signal strength and serial number using the signal from the strength detector, and provides the direction of the signal to the application target. We designed three different signal analysis units depending on the threshold type. The developed system can sense the direction to the transponder located over 10 m away within the maximum error of $5^{\circ}$. It falls within a reasonable range in our normal office environment.

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Data Quality Determination of Radio Occultation in moist troposphere

  • Yeh, Wen-Hao;Chiu, Tsen-Chieh;Liou, Yuei-An;Huang, Cheng-Yung
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2007년도 Proceedings of ISRS 2007
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    • pp.442-444
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    • 2007
  • How to observe the atmosphere is a subject of atmospheric research. The meteorological satellites and the ground states are used to do observation. However, both ways do not satisfy the requirement of scientists, especially the profiles of atmosphere on the ocean and the data for global atmosphere. Radio occultation (RO) technique, which has been used in planet science, is a method to solve the problem. In RO technique, the low Earth orbit (LEO) satellite receives the two frequency signal of Global Positioning System (GPS) satellite. The excess phase of the signal is calculated to retrieve the profiles of atmosphere parameters. In moist troposphere, the fluctuations appear in the phase of the signal and open loop (OL) is used to resolve it. The quality of the GPS signal generally deteriorates as the altitude decreases. In the procedure, the SNR of the GPS signal is used as the criterion. However, the SNR decreases with fluctuation which makes it difficult to locate the data of poor quality. In this paper, the phase of the signal will be used as part of the criterion.

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