Table 3 Linear and polynomial fitting relationships and inversion accuracy between the four vegetation indices (VIs) and FVC

y = 1.276x-0.008

0.717

10.8

y = -2.810x² + 4.536x-0.859

0.745

9.8

y = 1.212x + 0.269

0.635

12.1

y = -4.955x² + 5.673x-0.636

0.715

11.8

y = 1.482x + 0.172

0.665

11.4

y = -6.775x² + 7.180x-0.921

0.725

10.3

y = 1.210x + 0.299

0.642

11.7

y = -5.437x² + 5.881x-0.600

0.724

10.5