Related Articles

  • October 31, 2016

    0 32 7

    Improvement of COMS land surface temperature retrieval algorithm by considering diurnal variation of air temperature

    Youn-Young Choi and Myoung-Seok Suh†

    Korean Journal of Remote Sensing 2016; 32(5): 435-452

    Abstract
    Land Surface Temperature (LST) has been operationally retrieved from the Communication, Ocean, and Meteorological Satellite (COMS) data by the spilt-window method (CSW_v2.0) developed by Cho et al. (2015). Although the CSW_v2.0 retrieved the LST with a reasonable quality compared to the Moderate Resolution Imaging Spectroradiometer (MODIS) LST data, it showed a relatively poor performance for the strong inversion and lapse rate conditions. To solve this problem, the LST retrieval algorithm (CSW_v2.0) was updated using the simulation results of radiative transfer model (MODTRAN 4.0) by considering the diurnal variations of air temperature. In general, the upgraded version, CSW_v3.0 showed a similar correlation coefficient between the prescribed LSTs and retrieved LSTs (0.99), the relatively smaller bias (from -0.03 K to-0.012 K) and the Root Mean Square Error (RMSE) (from 1.39 K to 1.138 K). Particularly, CSW_v3.0 improved the systematic problems of CSW_v2.0 that were encountered when temperature differences between LST and air temperature are very large and/or small (inversion layers and superadiabatic lapse rates), and when the brightness temperature differences and surface emissivity differences were large. The bias and RMSE of CSW_v2.0 were reduced by 10-30% in CSW_v3.0. The indirect validation results using the MODIS LST data showed that CSW_3.0 improved the retrieval accuracy of LST in terms of bias (from -0.629 K to -0.049 K) and RMSE (from 2.537 K to 2.502 K) compared to the CSW_v2.0.
  • August 31, 2019

    0 9 16

    Comparison of Land Surface Temperatures from Near-surface Measurement and Satellite-based Product

    Jae-Hyun Ryu 1) · Hoejeong Jeong2) · Seonwoong Choi2) · Yang-Won Lee 3) · Jaeil Cho 4)†

    Korean Journal of Remote Sensing 2019; 35(4): 609-616

    https://doi.org/10.7780/kjrs.2019.35.4.9

    Abstract
    Land surface temperature (Ts) is a critical variable for understanding the surface energy exchange between land and atmosphere. Using the data measured from micrometeorological flux towers, three types of Ts, obtained using a thermal-infrared radiometer (IRT), a net radiometer, and an equation for sensible heat flux, were compared. The Ts estimated using the net radiometer was highly correlated with the Ts obtained from the IRT. Both values acceptably fit the Ts from the Terra/MODIS (Moderate Resolution Imaging Spectroradiometer)satellite. These results will enhance the measurement of land surface temperatures at various scales. Further, they are useful for understanding land surface energy partitioning to evaluate and develop land surface models and algorithms for satellite remote sensing products associated with surface thermal conditions.
  • February 28, 2021

    0 28 4

    Comparison of Land surface Temperature algorithm using Landsat-8 data for South Korea

    Sungwon Choi 1)· Kyeong-Sang Lee 1)· Minji Seo 1)· Noh-Hun Seong 1)· Donghyun Jin 1)· Daeseong Jung 2)· Suyoung Sim 2)· Gook Jung Im 3)· Kyung-Soo Han 4)†

    Korean Journal of Remote Sensing 2021; 37(1): 153-160

    https://doi.org/10.7780/kjrs.2021.37.1.12

    Abstract
    Land Surface Temperature (LST) is the radiological surface temperature which observed by satellite. It is very important factor to estimate condition of the Earth such as Global warming and Heat island. For these reasons, many countries operate their own satellite to bserve the Earth condition. South Korea has many landcovers such as forest, crop land, urban. Therefore, if we want to retrieve accurate LST, we would use high-resolution satellite data. In this study, we made LSTs with 4 LST retrieval algorithms which are used widely with Landsat-8 data which has 30 m spatial resolution. We retrieved LST using equations of Price, Becker et al., Prata, Coll et al. and they showed very similar spatial distribution. We validated 4 LSTs with Moderate resolution Imaging Spectroradiometer (MODIS) LST data to find the most suitable algorithm. As a result, every LST shows 2.160 ~ 3.387 K of RMSE. And LST by Prata algorithm show the lowest RMSE than others. With this validation result, we choose LST by Prata algorithm as the most suitable LST to South Korea
  • ArticleJune 30, 2023

    0 39 7

    Trend Analysis ofVegetation Changes of Korean Fir (Abies koreana Wilson) in Hallasan and Jirisan Using MODIS Imagery

    Minki Choo 1) · Cheolhee Yoo 2) · Jungho Im 3)* · Dongjin Cho 4) · Yoojin Kang 4) · Hyunkyung Oh 5) · Jongsung Lee 6)

    Korean Journal of Remote Sensing 2023; 39(3): 325-338

    https://doi.org/10.7780/kjrs.2023.39.3.6

    Abstract
    Korean fir (Abies koreana Wilson) is one of the most important environmental indicator tree species for assessing climate change impacts on coniferous forests in the Korean Peninsula. However, due to the nature of alpine and subalpine regions, it is difficult to conduct regular field surveys of Korean fir, which is mainly distributed in regions with altitudes greater than 1,000 m. Therefore, this study analyzed the vegetation change trend of Korean fir using regularly observed remote sensing data. Specifically, normalized difference vegetation index (NDVI) from Moderate Resolution Imaging Spectroradiometer (MODIS), land surface temperature (LST), and precipitation data from Global Precipitation Measurement (GPM) Integrated Multi-satellitE Retrievalsfor GPM from September 2003 to 2020 for Hallasan and Jirisan were used to analyze vegetation changes and their association with environmental variables. We identified a decrease in NDVI in 2020 compared to 2003 for both sites. Based on the NDVI difference maps, areas for healthy vegetation and high mortality of Korean fir were selected. Long-term NDVI time-series analysis demonstrated that both Hallasan and Jirisan had a decrease in NDVI at the high mortality areas (Hallasan: –0.46, Jirisan: –0.43). Furthermore, when analyzing the long-term fluctuations of Korean fir vegetation through the Hodrick-Prescott filter-applied NDVI, LST, and precipitation, the NDVI difference between the Korean fir healthy vegetation and high mortality sitesincreased with the increasing LST and decreasing precipitation in Hallasan. Thissuggests that the increase in LST and the decrease in precipitation contribute to the decline of Korean fir in Hallasan. In contrast, Jirisan confirmed a long-term trend of declining NDVI in the areas of Korean fir mortality but did not find a significant correlation between the changes in NDVI and environmental variables (LST and precipitation). Further analyses of environmental factors, such as soil moisture, insolation, and wind that have been identified to be related to Korean fir habitats in previous studies should be conducted. This study demonstrated the feasibility of using satellite data for long-term monitoring of Korean fir ecosystems and investigating their changes in conjunction with environmental conditions. Thisstudy provided the potential forsatellite-based monitoring to improve our understanding of the ecology of Korean fir.
  • Research ArticleDecember 31, 2024

    0 76 33

    Analysis of Hotspot Changes in Daegu Metropolitan City in Summer Using Landsat 8 Satellite Images

    Yejin Lee, Kyungil Lee, Seonyoung Park

    Korean Journal of Remote Sensing 2024; 40(6): 1379-1389

    https://doi.org/10.7780/kjrs.2024.40.6.2.9

    Abstract
    Increasing temperature due to climate change and the urban heat island effect caused by rapid urbanization can deteriorate the thermal environment in urban areas, leading to negative impacts such as increased heat stress during summer and higher energy consumption. In particular, basin topography is considered an ideal area for studying changes in the thermal environment, as its structure hinders the escape of heat from the city, making these issues more pronounced. In this study, a thermal environment based on the hotspot in the summer of Daegu Metropolitan City, a representative basin topography, from 2013 to 2023 was analyzed using Landsat 8 Operational Land Imager/Thermal Infrared Sensor (OLI/TIRS) satellite images. The land surface temperature (LST) was calculated from the thermal infrared band of the satellite image and LST was normalized between 0 and 1 in consideration of outliers and clouds. Hotspot change analysis was performed by calculating the ratio of hotspots to the total area for the entire year. Results showed an increase in hotspot areas compared to previous years, with larger expansions observed in years with severe heatwaves. Subsequently, Moran’s I and Local Indicator of Spatial Association (LISA) analysis were used to confirm clustering patterns within the thermal environment. This study identifies hotspot variations due to summer heatwaves, and this thermal environment analysis is anticipated to contribute to policies aimed at improving the urban thermal environment.
KSRS
December 2024 Vol. 40, No. 6, pp. 881-1521

Most Keyword ?

What is Most Keyword?

  • It is the most frequently used keyword in articles in this journal for the past two years.

Most View

Editorial Office

Korean Journal of Remote Sensing