## 3 Results
### Optimisation of the Extraction Method
\begin{table}
\begin{tabular}{l c c c c c c c c c c c c} \hline \hline  & & \multicolumn{4}{c}{**SOS**} & \multicolumn{4}{c}{**POS**} & \multicolumn{4}{c}{**EOS**} \\ \cline{2-13}  & & **ELM** & **GU** & **BEC** & **KLS** & **ELM** & **GU** & **BEC** & **KLS** & **ELM** & **GU** & **BEC** & **KLS** \\ \hline
**GU** & MAE & 15.2 & 17.1 & 15.2 & 17.4 & **13.4** & 14.4 & 13.9 & 12.5 & 19.2 & 21.6 & 25.3 & 24.7 \\  & R\({}^{2}\) & 0.76 & 0.74 & 0.75 & 0.83 & **0.66** & 0.62 & 0.54 & 0.56 & 0.08 & 0.06 & 0.00 & 0.05 \\  & AIC & 627 & 671 & 647 & 577 & **647** & 652 & 651 & 614 & 533 & 595 & 527 & 496 \\  & RMSE & 19.2 & 21.5 & 20.0 & 20.7 & **18.5** & 19.3 & 19.3 & 18.0 & 26.0 & 26.3 & 29.2 & 29.7 \\  & PP & 93 & 96 & 94 & 88 & **91** & 93 & 93 & 88 & 77 & 83 & 73 & 72 \\ \hline
**DER** & MAE & 15.0 & 16.9 & 14.2 & 12.6 & 16.2 & 28.6 & 23.8 & 16.8 & 18.8 & 35.8 & 39.5 & 36.3 \\  & R\({}^{2}\) & 0.63 & 0.69 & 0.73 & 0.77 & 0.55 & 0.49 & 0.30 & 0.61 & 0.09 & 0.05 & 0.12 & 0.16 \\  & AIC & 682 & 668 & 674 & 568 & 512 & 480 & 530 & 416 & 557 & 498 & 560 & 479 \\  & RMSE & 21.1 & 21.9 & 17.8 & 16.3 & 21.1 & 34.6 & 30.2 & 23.7 & 25.4 & 40.6 & 43.1 & 40.1 \\  & PP & 95 & 95 & 99 & 86 & 73 & 64 & 69 & 56 & 79 & 69 & 80 & 72 \\ \hline
**KLS** & MAE & 17.4 & 15.0 & 13.9 & 19.5 & 10.3 & 15.8 & 13.9 & 13.6 & 22.6 & 23.3 & 24.1 & 27.1 \\  & R\({}^{2}\) & 0.85 & 0.73 & 0.57 & 0.6 & 0.89 & 0.57 & 0.57 & 0.71 & 0.00 & 0.00 & 0.02 & 0.17 \\  & AIC & 116 & 300 & 582 & 505 & 110 & 345 & 582 & 431 & 104 & 222 & 458 & 351 \\  & RMSE & 21.5 & 18.2 & 19.0 & 24.0 & 13.1 & 22.2 & 19.0 & 19.3 & 33.1 & 29.5 & 28.65 & 32.7 \\  & PP & 17 & 46 & 83 & 69 & 16 & 47 & 83 & 60 & 16 & 30 & 64 & 47 \\ \hline
**TRS\({}_{\textbf{0.1}}\)** & MAE & 15.4 & 19.4 & 21.0 & 19.2 & 16.2 & 28.5 & 23.8 & 16.8 & 21.1 & 21.5 & 22.9 & 24.4 \\  & R\({}^{2}\) & 0.35 & 0.57 & 0.56 & 0.51 & 0.55 & 0.49 & 0.30 & 0.61 & 0.06 & 0.06 & 0.00 & 0.00 \\  & AIC & 635 & 612 & 651 & 598 & 512 & 480 & 530 & 416 & 589 & 302 & 325 & 235 \\  & RMSE & 19.3 & 24.1 & 25.7 & 24.3 & 21.06 & 34.6 & 30.2 & 23.7 & 26.5 & 26.0 & 28.0 & 30.0 \\  & PP & 91 & 83 & 94 & 81 & 73 & 64 & 69 & 56 & 84 & 46 & 48 & 33 \\ \hline
**TRS\({}_{\textbf{0.2}}\)** & MAE & 14.0 & 14.8 & 13.6 & 15.8 & - & - & - & - & 22.8 & 21.9 & 24.9 & 25.9 \\  & R\({}^{2}\) & 0.78 & 0.79 & 0.79 & 0.91 & - & - & - & - & 0.14 & 0.14 & 0.01 & 0.09 \\  & AIC & 609 & 611 & 625 & 497 & - & - & - & - & 588 & 498 & 583 & 459 \\  & RMSE & 17.7 & 19.7 & 17.6 & 19.5 & - & - & - & 28.3 & 27.0 & 30.4 & 30.2 \\  & pp & 91 & 89 & 94 & 75 & - & - & - & - & 85 & 72 & 80 & 68 \\ \hline
**TRS\({}_{\textbf{0.3}}\)** & MAE & 13.6 & 15.0 & 12.9 & 14.6 & - & - & - & - & 27.5 & 29.4 & 28.9 & 31.6 \\  & R\({}^{2}\) & 0.82 & 0.85 & 0.80 & 0.86 & - & - & - & - & 0.12 & 0.16 & 0.07 & 0.15 \\  & AIC & 599 & 593 & 627 & 553 & - & - & - & - & 588 & 547 & 548 & 529 \\  & RMSE & **16.9** & 19.0 & 16.2 & 17.9 & & & & & 32.0 & 33.8 & 33.9 & 35.8 \\  & PP & **91** & 90 & 95 & 86 & - & - & - & - & 85 & 79 & 78 \\ \hline
**TRS\({}_{\textbf{0.4}}\)** & MAE & 13.7 & 14.9 & 12.8 & 13.3 & - & - & - & - & 34.2 & 36.1 & 35.5 & 36.6 \\  & R\({}^{2}\) & 0.80 & 0.81 & 0.79 & 0.80 & - & - & - & - & 0.10 & 0.22 & 0.14 & 0.22 \\  & AIC & 629 & 624 & 626 & 580 & - & - & - & - & 569 & 574 & 545 & 522 \\  & RMSE & 18.1 & 19.3 & 15.9 & 16.7 & & & & 38.4 & 39.4 & 39.1 & 39.8 \\  & PP & 94 & 93 & 95 & 88 & - & - & - & - & 83 & 83 & 79 & 78 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Goodness of fit indicators between phenological dates extracted from GPP and kNDVI patterns with different FM\(\times\)EM approaches. The results underlined and in bold are those relating to the approach chosen for the start (SOS) and peak (POS) of the season, respectively. the low performance in determining EOS through the kNDVI index, the end of the season was not considered in the analysis over the 2001-2021 period.