# Monitoring and Forecasting Green Tide in the Yellow Sea Using Satellite Imagery
## 2 Description of the Dataset
### RS Dataset  
The main satellites from which RS data were obtained for this study were Gaofen-1 (GF-1), Landsat 5 Thematic Mapper (TM), Landsat 8 operational land imager_thermal infrared sensor (OLI_TIRS), Huanjing-1A/B (HJ-1A/B), HaiYang-1C (HY-1C), and moderate-resolution imaging spectroradiometer (MODIS). As the first satellite in the space-based system of the major special project of China's high-resolution earth observation system, the GF-1 satellite goes beyond optical RS by combining high-temporal-resolution, multi-spectral, and wide coverage and is a leader among international civil optical RS satellites in terms of the comprehensive indices of resolution and width. We used the GF-1 Wide Field-of-View (WFV) satellite data product ([[http://36.112.130.153:7777/](http://36.112.130.153:7777/)]([http://36.112.130.153:7777/](http://36.112.130.153:7777/)), accessed on 20 July 2022), which was launched in 2013. The spatial resolution of all bands is 16 m, with a temporal resolution of 4 days. We used RS image band 4 (_Red_) and band 3 (Near-Infrared, _NIR_). Further, we used the Landsat 5 TM Level 1 (L1) and Landsat8 OLL_TIRS L1 products ([[https://eartheplorer.usgs.gov/](https://eartheplorer.usgs.gov/)]([https://eartheplorer.usgs.gov/](https://eartheplorer.usgs.gov/)), accessed on 20 July 2022). The Landsat 5 TM satellite has seven bands. The spatial resolution of bands 1-5 and 7 is 30 m, and that of band 6 is 120 m. The Landsat8 OLL_TIRS satellite has 11 bands. The spatial resolution of bands 1-7 and 9-11 is 30 m, and band 8 is a panchromatic band with a resolution of 15 m. These two satellites  
Figure 1: Study area and Location diagram of extraction regions in different environments for accuracy assessment ((**a**) Partition diagram, where the red line is the \(-\)35 m isobath and the area within the green line represents Zone C, which is the muddy water area. (**b**) Accuracy assessment areas A1–A3, B1–B3, and C1–C3 corresponding to the three partitions of A, B, and C). provide global coverage every 16 days. We used RS image band 3 (_Red_) and band 4 (_NIR_) from Landsat 5 TM, and band 4 (_Red_) and band 5 (_NIR_) from Landsat 8 OLI_TIRS. We also used Landsat 8 OLI_TIRS L2 C2 products; this dataset is the atmosprically corrected surface reflectance from the Landsat 8 OLI/TIRS sensor for the identification of _U. prolifera_ and Sargassum by the spectral shape. The environmental and disaster monitoring and prediction small satellite constellation A/B (HJ-1A/B) was launched in September 2008. The HJ-1A satellite is equipped with a CCD camera and a hyperspectral imager, while the HJ-1B satellite is equipped with a CCD camera and an infrared camera (IRS). We used the HJ-1A/B satellite CCD products of band 3 (_Red_) and band 4 (_NIR_) ([[http://36.112.130.153:7777/](http://36.112.130.153:7777/)]([http://36.112.130.153:7777/](http://36.112.130.153:7777/)), accessed on 20 July 2022), which have a spatial resolution of 30 m and a temporal resolution of 4 days. The HY-1C satellite project provides a series of observations in the morning and afternoon, which improves the global coverage ability, enlarges the coverage width of the coastal zone imager, and improves spatial resolution to meet practical needs. We used the L1C product of the HY-1C satellite coastal zone imaging instrument (CZI), which has a spatial resolution of <50 m and a temporal resolution of 3 days ([[https://osdds.nsoas.org.cn/](https://osdds.nsoas.org.cn/)]([https://osdds.nsoas.org.cn/](https://osdds.nsoas.org.cn/)), accessed on 20 July 2022). Specifically, we used RS image band 1 (_Red_) and band 2 (_NIR_). We also used HY-1C L2A products; this dataset is the rayleigh corrected reflectance from the HY-1C sensor for the identification of _U. prolifera_ and Sargassum by the spectral shape.