## 4 Results  
### Vector Processing Results Based on the Multi-Correlation Coefficient Algorithm  
Figure 7 shows a group of daily surface vectors obtained by the multi-correlation coefficient algorithm with TSM as the background on 13 August 2013; the rotation direction  
Figure 6: (**a**) An illustration of SSC vector estimation by multi-correlation coefficient inversion algorithm. \(T\) is the matching template, \(T^{\prime}\) is the mapping of the matching template at the same position in the search area, \(I_{1}\), \(I_{2}\) and \(I_{3}\) are the regions searched by the matching template, and \(a_{1}\), \(a_{2}\) and \(a_{3}\) are the current field vectors under the corresponding correlation coefficients; (**b**) an illustration of vector direction judgment. (**c**) An illustration of spurious vector judgment. is clockwise. In the period of 11:30-12:30 local time, the vector under the first correlation coefficient had inversion error, and there was no significant difference in the three vectors obtained in the remaining period, which confirms the existence of the mismatch. We selected 35 sets of case data, as shown in Figure 8b. Our method eliminates the spurious vectors in seven daily vectors (black dashed arrows in Figure 8b). As illustrated in Figure 8b, the GOCI vectors under the first three correlation coefficients obtained by the MCC algorithm are different in some time periods, and the spurious vectors under the 1 st correlation coefficient can be identified by the established vector rotation direction in the OSU model. However, the case data used for evaluation should meet the following requirements: the selection of measured data should meet the corresponding GOCI data to obtain good satellite images within eight hours of each day. During the life cycle of the drifting buoys, we found that GOCI images on 10-11,13 August 2013, in the East China Sea and those on 27 June and 11,16 July 2012, and on 4-6 August 2012, in the Yellow Sea  
Figure 7: A group of daily surface vectors obtained by the multi-correlation coefficient algorithm with TSM as the background on 13 August 2013. The three colored vector arrows and boxes in (**a–g**) correspond to the SSC vectors and matching windows obtained under the first three correlation coefficients, respectively. The red box in (**h**) is where subplots (**a–g**) are located. were of high quality due to the relatively small cloud cover extent (Figure 1). Due to the complexity of the current system in the East China Sea, the current speed and direction will be quite different at different locations at the same time. Therefore, the selection of case data should meet the selected case consistent with the measured data, and should be as close as possible to the measured point position. In summary, we selected nine sets of case data in different sea areas to evaluate the new method. Figure 8a shows the distribution of measured data points and case data points. The case data that can be used for evaluation are close to the corresponding buoy points. The processing results of vectors are shown in Figure 9a-c), corresponding to the cases of the East China Sea, southern Yellow Sea, and northern Yellow Sea, respectively; there are differences among the results of each case. For example, in the East China Sea (Figure 9a) and the southern Yellow Sea (Figure 9b), the rotational direction of the fitted tidal ellipse was clockwise in the GOCI matching day and counterclockwise in the northern Yellow Sea (Figure 9c); the angle deviation between the buoy vector and GOCI vector in the northern Yellow Sea area was large, and the current direction shows reversing current characteristics. Furthermore, there are also differences in the number of error vectors identified. The number of error vectors identified on 16 July and 6 August was the 5 th, 7 th vector and the 1 st, 6 th vector, respectively; one vector was identified on the other days.