• Title/Summary/Keyword: Timesat

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Analysis of MODIS LAI and NDVI Patterns of Broad-leaved Trees by the Timesat Program on the Korean Peninsula (Timesat 프로그램에 의한 한반도 활엽수의 지역별 MODIS LAI 및 NDVI 패턴 분석)

  • Seo, Dae Kyo;Lee, Jeong Min;Lim, Ye Seul;Han, Sang Won;Pyeon, Mu Wook
    • Journal of Korean Society for Geospatial Information Science
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    • v.25 no.2
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    • pp.13-19
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    • 2017
  • This paper analyzed MODIS data from 2006 to 2013 to determine relationship between meteorological changes and vegetation index. The experimental area was divided into the northern, central and southern regions according to the regional characteristics, and the smoothed MODIS LAI and NDVI were obtained using Timesat. In the case of precipitation, MODIS NDVI had correlation coefficients of 0.66, 0.44 and 0.35 in the northern, central and southern regions and the correlation was the highest in the northern region. In the case of temperature, MODIS LAI had correlation coefficients of 0.66, 0.64 and 0.68, and MODIS NDVI had 0.89, 0.89 and 0.80. The correlation of MODIS NDVI was higher and showed similar positive correlation regardless of region. In addition, The accuracy between Timesat plant seasonal start and actual plant seasonal start in MODIS NDVI was higher than MODIS LAI. The average error in MODIS LAI was 19 days in the central region and 20 days in the southern region. And the average error in MODIS NDVI was 6 days in the central region and 8 days in the southern region.

A Phenology Modelling Using MODIS Time Series Data in South Korea (MODIS 시계열 자료(2001~2011) 및 Timesat 알고리즘에 기초한 남한 지역 식물계절 분석)

  • Kim, Nam-Shin;Cho, Yong-Chan;Oh, Seung-Hwan;Kwon, Hye-Jin;Kim, Gyung-Soon
    • Korean Journal of Ecology and Environment
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    • v.47 no.3
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    • pp.186-193
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    • 2014
  • This study aimed to analyze spatio-temporal trends of phenological characteristics in South Korea by using MODIS EVI. For the phenology analysis, we had applied double logistic function to MODIS time-series data. Our results showed that starting date of phenology seems to have a tendency along with latitudinal trends. Starting date of phenology of Jeju Island and Mt. Sobeak went back for 0.38, 0.174 days per year, respectively whereas, Mt. Jiri and Mt. Seolak went forward for 0.32 days, 0.239 days and 0.119 days, respectively. Our results exhibited the fluctuation of plant phonological season rather than the change of phonological timing and season. Starting date of plant phenology by spatial distribution revealed tendency that starting date of mountain area was late, and basin and south foot of mountain was fast. In urban ares such as Seoul metropolitan, Masan, Changwon, Milyang, Daegu and Jeju, the phonological starting date went forward quickly. Pheonoligcal attributes such as starting date and leaf fall in urban areas likely being affected from heat island effect and related warming. Our study expressed that local and regional monitoring on phonological events and changes in Korea would be possible through MODIS data.