• Title/Summary/Keyword: satellite rainfall

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Flood Monitoring Using River Flow Forecasting Model with Special Reference to Luangwa River

  • Ngoma, Solomon
    • 한국농림기상학회:학술대회논문집
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    • 한국농림기상학회 2001년도 춘계 학술발표논문집
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    • pp.38-38
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    • 2001
  • The rainfall estimates give sufficiently accurate information to map areas which have received the minimum rainfall necessary for outbreaks of pests such as locusts, thus cutting down the cost of searching for likely outbreak sites. At the other end of the scale, satellite rainfall estimates can be used to give timely warnings of changes in river levels and the likelihood of floods in large river catchments.(omitted)

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Case study on the Accuracy Assessment of the rainrate from the Precipitation Radar of TRMM Satellite over Korean Peninsula

  • Chung, Hyo-Sang;Park, Hye-Sook;Noh, Yoo-Jeong
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 1999년도 Proceedings of International Symposium on Remote Sensing
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    • pp.103-106
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    • 1999
  • The Tropical Rainfall Measuring Mission(TRMM) is a United States-Japan project for rain measurement from space. The first spaceborne Precipitation Radar(PR) has been installed aboard the TRMM satellite. The ground based validation of the TRMM satellite observations was conducted by TRMM science team through a Global Validation Program(GVP) consisted of 10 or more ground validation sites throughout the tropics. However, TRMM radar should always be validated and assessed against reference data to be used in Korean Peninsula because the rainrates measured with satellite varies by time and space. We have analyzed errors in the comparison of rainrates measured with the TRMM/PR and the ground-based instrument i.e. Automatic Weather System(AWS) by means of statistical methods. Preliminary results show that the near surface rainrate of TRMM/PR are highly correlated with ground measurements especially for the very deep convective rain clouds, though the correlation is changed according to the type and amount of precipitating clouds. Results also show that TRMM/PR instrument is inclined to underestimate the rainrate on the whole over Korea than the AWS measurement for the cases of heavy rainfall.

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Fresh water impact on chlorophyll a distribution at northeast coast of the Bay of Bengal analyzed through in-situ and satellite data

  • Mishra, R.K.;Senga, Y.;Nakata, K.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.122-125
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    • 2006
  • The distribution of phytoplankton pigments were studied bimonthly at four stations from the mouth of Mahanadi River at Paradip to the 36.7km off coast in Bay of Bengal during April 2001 to December 2002. Bottom depth was shallower than 40m in all stations. The pigment concentration of Chl-a was measured. It increased from surface to bottom in the water column. The water column integrated chlorophyll-a concentration (Chl-a) varied between 6.1 and $48.5mg{\cdot}m-^2$ with peaks during monsoon period (Aug & Oct). Spatial distribution of salinity depended strongly on freshwater runoff. The salinity was 5psu at river mouth and 25.15psu at offshore in monsoon period; however it was 30psu at the river mouth in summer. We found a linear relationship between the amount of river discharge and integrated Chl-a in coastal region from 2 years observations. Extending this result, we analyzed rainfall and coastal Chl-a using satellite data. The relationship between the river discharge and monthly accumulated rainfall estimated from TRMM and others data sources was analyzed in 2001 and 2002 using Giovanni infrastructure provided by NASA. The result depended on the specified area on TRMM images; the river delta area had sharper relationship than wider rain catchments area. Moreover, the relationship between monthly averaged Chl-a derived from SeaWiFS and monthly accumulated rainfall estimated from TRMM was analyzed from 1998 to 2005. It was clear that the broom in monsoon period was strongly controlled by rainfall on river delta.

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Status of Rice Paddy Field and Weather Anomaly in the Spring of 2015 in DPRK

  • Hong, Suk Young;Park, Hye-Jin;Jang, Keunchang;Na, Sang-Il;Baek, Shin-Chul;Lee, Kyung-Do;Ahn, Joong-Bae
    • 한국토양비료학회지
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    • 제48권5호
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    • pp.361-371
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    • 2015
  • To understand the impact of 2015 spring drought on crop production of DPRK (Democratic People's Republic of Korea), we analyzed satellite and weather data to produce 2015 spring outlook of rice paddy field and rice growth in relation to weather anomaly. We defined anomaly of 2015 for weather and NDVI in comparison to past 5 year-average data. Weather anomaly layers for rainfall and mean temperature were calculated based on 27 weather station data. Rainfall in late April, early May, and late May in 2015 was much lower than those in average years. NDVI values as an indicator of rice growth in early June of 2015 was much lower than in 2014 and the average years. RapidEye and Radarsat-2 images were used to monitor status of rice paddy irrigation and transplanting. Due to rainfall shortage from late April to May, rice paddy irrigation was not favorable and rice planting was not progressed in large portion of paddy fields until early June near Pyongyang. Satellite images taken in late June showed rice paddy fields which were not irrigated until early June were flooded, assuming that rice was transplanted after rainfall in June. Weather and NDVI anomaly data in regular basis and timely acquired satellite data can be useful for grasping the crop and land status of DPRK, which is in high demand.

한반도 중부지역에서의 SAR Sentinel-1 위성강우량 추정에 관한 예비평가 (A preliminary assessment of high-spatial-resolution satellite rainfall estimation from SAR Sentinel-1 over the central region of South Korea)

  • 능엔 호앙 하이;정우성;이달근;신대윤
    • 한국수자원학회논문집
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    • 제55권6호
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    • pp.393-404
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    • 2022
  • 위성에서 보다 미세한 공간 분해능으로 신뢰할 수 있는 지상 강우 관측은 도시 수문학적 및 미시적 농업 수요에 필수적이다. 전통적으로 "톱다운" 접근 방식 기반 위성 강우 산출물이 널리 사용되고 있지만 공간 분해능에 한계가 있다. 본 연구는 C-밴드 SAR Sentinel-1 위성 데이터(SM2RAIN-S1)에 적용되는 매개 변수화된 SM2RAIN 모델인 강우 추정을 위한 새로운 "상향식" 접근 방식의 가능성을 평가하여 중부지방에 대한 높은 공간 분해능 지상 강우 추정치(0.01° 그리드/6일)를 생성하는 것을 목표로 한다. 그것의 성능은 중부지방 두 개의 다른 하위 지역, 즉 혼합 산림 중심, 중간 하위 지역, 그리고 경작 중심, 서해안 하위 지역의 1년 기간 동안 기존의 재분석 프로덕트와 우량계 네트워크의 각각의 강우 데이터를 사용하여 공간 및 시간적 가변성에 대해 평가되었다. 평가결과에 따르면 SM2RAIN-S1 프로덕트는 중부지방의 일반적인 강우 패턴을 포착할 수 있고, 서로 다른 토지 피복으로 지역 규모에서 공간 분해능 강우량 측정 가능성을 보유할 수 있으며, 강우량 관측치에 대한 편중된 강우량 추정치가 제공되었다. 또한 SM2RAIN-S1 강우량은 피어슨의 상관 계수(R = 0.69)를 고려할 때 혼합림에서 더 우수했으며, 이는 혼합림에서 토양 수분과 강우의 시간 역학을 포착하는 데 6일 SM2RAIN-S1 데이터의 적합성을 암시했다. 그러나, RMSE와 바이어스 측면에서, 혼합림보다는 경작지의 SM2RAIN-S1 강우 생성물에서 더 나은 성능을 얻었으며, 이는 높은 증발증산 손실(특히 혼합림)에 의해 유도된 더 큰 오류를 SM2RAIN의 추가 개선에 포함해야 한다는 것을 나타낸다.

위성기반 Climate Hazards Group InfraRed Precipitation with Station (CHIRPS)를 활용한 한반도 지역의 기상학적 가뭄지수 적용 (Application of Meteorological Drought Index using Climate Hazards Group InfraRed Precipitation with Station (CHIRPS) Based on Global Satellite-Assisted Precipitation Products in Korea)

  • 문영식;남원호;전민기;김태곤;홍은미
    • 한국농공학회논문집
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    • 제61권2호
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    • pp.1-11
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    • 2019
  • Remote sensing products have long been used to monitor and forecast natural disasters. Satellite-derived rainfall products are becoming more accurate as space and time resolution improve, and are widely used in areas where measurement is difficult because of the periodic accumulation of images in large areas. In the case of North Korea, there is a limit to the estimation of precipitation for unmeasured areas due to the limited accessibility and quality of statistical data. CHIRPS (Climate Hazards Group InfraRed Precipitation with Stations) is global satellite-derived rainfall data of 0.05 degree grid resolution. It has been available since 1981 from USAID (U.S. Agency for International Development), NASA (National Aeronautics and Space Administration), NOAA (National Oceanic and Atmospheric Administration). This study evaluates the applicability of CHIRPS rainfall products for South Korea and North Korea by comparing CHIRPS data with ground observation data, and analyzing temporal and spatial drought trends using the Standardized Precipitation Index (SPI), a meteorological drought index available through CHIRPS. The results indicate that the data set performed well in assessing drought years (1994, 2000, 2015 and 2017). Overall, this study concludes that CHIRPS is a valuable tool for using data to estimate precipitation and drought monitoring in Korea.

강우감쇠 유효경로 길이 예측을 위한 경험 모델 (An Empircal Model of Effective Path Length for Rain Attenuation Prediction)

  • 이주환;최용석;박동철
    • 한국전자파학회논문지
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    • 제11권5호
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    • pp.813-821
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    • 2000
  • 위성통신 경로의 강우감쇠량을 예측하기 위하여 국제적으로 여러 가지 예측모델들이 개발 운용되고 있다. 이러한 예측 모델들은 대부분 미국과 유럽을 비롯한 위성 선진국에서 개발한 것으로 국내의 강우환경을 고려하여 개발된 모델은 없는 실정이다. 본 논문에서는 한국전자통신연구원에서 측정한 강우환경 및 강우감쇠 데이터를 이용하여, 국내 위성통신망에서 고려할 수 있는 강우감쇠량 예측 방법에 대해 기술하였다. 특히, 기존 예측 모델들이 적용한 강우경로의 수평적 변화를 고려한 유효경로 길이 예측 기법에서 탈피하여, 위성통신망에서 필연적으로 고려하여야 할 강우경로의 수직적 변화까지도 고려한 유효경로 예측기법을 유도하고 이를 제안하였다. 본 논문에서 제안한 예측 기법은 국내 강우환경에 적합한 예측 기법으로써, 향후 설계 및 운용될 10GHz 이상의 국내 위성 및 무선통신시스템에 매우 효율적으로 활용할 수 있을 것이다. ^u The engineering of satellite communication systems at frequencies above 10GHz requires a method for estimating rain-caused outage probabilities on the earth-satellite path. A procedure for predicting a rain attenuation distribution from a point rainfall rate distribution is, therefore, needed. In order to predict rain attenuation on the satellite link, several prediction models such as ITU-R, Global, SAM, DAH model, have been developed and used at a particular propagation condition, they may not be appropriate to a propagation condition in Korean territory. In this paper, a new rain attenuation prediction method appropriate to a propagation condition in Korea is introduced. Based on the results from ETRI measurements, a new method has been derived for an empirical approach with an identification on the horizontal correction factor as in current ITU-R method, and the vertical correction factor has been suggested with decreasing power law as a function of rainfall rate. This proposed model uses the entire rainfall rate distribution as input to the model, while the ITU-R and DAH model approaches only use a single 0.01% annual rainfall rate and assume that the attenuation at other probability levels can be determined from that single point distribution. This new model was compared with several world-wide prediction models. Based on the analysis, we can easilty know the importance of the model choice to predict rain attenuation for a particular location in the radio communication system design.

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Study on the Link Analysis for Satellite Broadcasting Service Using Ka Band Transponders in the Korean Area

  • 윤기창;김승철;손원
    • 한국위성정보통신학회논문지
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    • 제3권2호
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    • pp.7-12
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    • 2008
  • The study discussed the link analysis for the Ka band satellite broadcasting service in Korea with respect to the transmission schemes based on the DVB-S2 standard. To analyze the effect of the rain fading to the link budget, we estimated the rain attenuation from the measured rainfall intensity in Korea. We analyzed the link budget for the Ka band transponders of Koreasat-3, and DirecTV BSS-99W, and showed the possible link availability with the DVB-S2 transmission schemes for each transponder. Based on the link analysis of the available satellites with the Ka band transponders, we suggested the required EIRP for the satellite which will be employed for the Ka band satellite broadcasting service in Korea.

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다중시기 Sentinel-2 위성영상과 일강수량 자료를 활용한 집중호우 전후의 토지피복별 원격탐사지수 변화 분석 (Analysis on the Changes of Remote Sensing Indices on Each Land Cover Before and After Heavy Rainfall Using Multi-temporal Sentinel-2 Satellite Imagery and Daily Precipitation Data)

  • 김경섭;문갑수;정윤재
    • 한국지리정보학회지
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    • 제23권2호
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    • pp.70-82
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    • 2020
  • 최근 도시홍수에 의해 많은 피해가 발생하고 있으며, 단시간에 국지적으로 발생하는 집중호우가 1차 원인으로 꼽히고 있다. 도시홍수의 피해는 도시지역 내 물수지의 변화로 규명하고 있으며, 이를 간접적으로 파악하기 위해 일강수량 자료와 다중시기 Sentinel-2 위성영상을 활용해 집중호우 전후의 토지피복별 원격탐사지수 변화를 분석하였다. 일강수량 자료를 바탕으로 호우주의보 및 경보의 사례를 선정하였고, 해당 기간의 Sentinel-2 위성영상을 취득해 이를 기상청 서울관측소 기준 반경 1,000m 범위의 정규식생지수(NDVI), 정규수분지수(NDWI) 및 정규습윤지수(NDMI) 영상을 토지피복별로 제작하여 통계적 변화를 비교하였다. 각 영상을 구성하고 있는 픽셀의 최댓값, 최솟값, 평균 및 그 증감을 분석한 결과, 집중호우 전후 도시지역 원격탐사지수에 유의미한 변화가 발생한 것으로 보기는 힘들다고 판단하였다.