• Title/Summary/Keyword: near-field optical

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Validation of GOCI-II Products in an Inner Bay through Synchronous Usage of UAV and Ship-based Measurements (드론과 선박을 동시 활용한 내만에서의 GOCI-II 산출물 검증)

  • Baek, Seungil;Koh, Sooyoon;Lim, Taehong;Jeon, Gi-Seong;Do, Youngju;Jeong, Yujin;Park, Sohyeon;Lee, Yongtak;Kim, Wonkook
    • Korean Journal of Remote Sensing
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    • v.38 no.5_1
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    • pp.609-625
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    • 2022
  • Validation of satellite data products is critical for subsequent analysis that is based on the data. Particularly, performance of ocean color products in turbid and shallow near-land ocean areas has been questioned for long time for its difficulty that stems from the complex optical environment with varying distribution of water constituents. Furthermore, validation with ship-based or station-based measurements has also exhibited clear limitation in its spatial scale that is not compatible with that of satellite data. This study firstly performed validation of major GOCI-II products such as remote sensing reflectance, chlorophyll-a concentration, suspended particulate matter, and colored dissolved organic matter, using the in-situ measurements collected from ship-based field campaign. Secondly, this study also presents preliminary analysis on the use of drone images for product validation. Multispectral images were acquired from a MicaSense RedEdge camera onboard a UAV to compensate for the significant scale difference between the ship-based measurements and the satellite data. Variation of water radiance in terms of camera altitude was analyzed for future application of drone images for validation. Validation conducted with a limited number of samples showed that GOCI-II remote sensing reflectance at 555 nm is overestimated more than 30%, and chlorophyll-a and colored dissolved organic matter products exhibited little correlation with in-situ measurements. Suspended particulate matter showed moderate correlation with in-situ measurements (R2~0.6), with approximately 20% uncertainty.