Official Journal of the Asia Oceania Geosciences Society (AOGS)
Table 3 Four algorithms for detecting harmful algal blooms
From: Use of GOCI-II images for detection of harmful algal blooms in the East China Sea
Algorithm | MODIS | GOCI-II | Threshold value | References |
|---|---|---|---|---|
\({\text{RI}}=\frac{{R}_{rs}({\lambda }^{+})-{R}_{rs}({\lambda }^{-})}{{R}_{rs}(\lambda )-{R}_{rs}({\lambda }^{-})}\) | \({\lambda }^{+}=555\) \({\lambda }^{-}=443\) \(\lambda=488\) | \({\lambda }^{+}=555\) \({\lambda }^{-}=443\) \(\lambda=490\) | RI > 2.8 | Lou and Hu (2014) |
\({\text{SS}}(\lambda )={R}_{rs}\left(\lambda \right)-{R}_{rs}\left({\lambda }^{-}\right)-({R}_{rs}({\lambda }^{+})-{R}_{rs}({\lambda }^{-}))\times \frac{\lambda -{\lambda }^{-}}{{\lambda }^{+}-{\lambda }^{-}}\) | \({\lambda }^{+}=555\) \({\lambda }^{-}=488\) \(\lambda=531\) | \({\lambda }^{+}=555\) \({\lambda }^{-}=490\) \(\lambda=510\) | SS (510) < 0 | Wynne et al. (2008) |
\({\text{LHR}}=\frac{{\text{LH}}({\lambda }_{1})}{{\text{LH}}({\lambda }_{2})}\) | ||||
\({\text{LH}}({\lambda }_{i})={R}_{rs}({\lambda }_{i})-{R}_{rs}(660)-({R}_{rs}(745)-{R}_{rs}(660))\times \frac{({\lambda }_{i}-660)}{(745-660)}\) | *1 | \({\lambda }_{1}=709\) \({\lambda }_{2}=680\) | LHR > 0.6 | Tao et al. (2011) |
\({R}_{AB}=\frac{{R}_{rs}({\lambda }^{+})}{{R}_{rs}({\lambda }^{-})}\) | \({\lambda }^{+}\)=555 \({\lambda }^{-}\)= 531 | \({\lambda }^{+}=555\) \({\lambda }^{-}= 510\) | \({R}_{AB}\) > 1.25 | Tao et al. (2015) |