*3.2. Time Series Experiment of Vegetation*

During the experiments, measurements were made once every 3 days, and five groups of experiments were carried out, respectively. Spectral data of the leaves were collected to calculate the NDVI. Figure 10 shows the NDVI time series picture, in which the red arrow refers to the corresponding color picture, and the illumination is 0.5 lux.

**Figure 10.** Vegetation index (NDVI) in a time series. Illumination of the NDVI: (**a**) 0.01 lux, (**b**) 0.1 lux, (**c**) 0.5 lux, (**d**) 1.0 lux and (**e**) 5.0 lux.

Figure 11a–e is a fusion image (NDAI) calculated from the NDVI, DoLP and AOP. It can be seen that the fusion image can track the information of the changes in the leaf health status.

**Figure 11.** The fusion image in a time series. Illumination of the NDAI: (**a**) 0.01 lux, (**b**) 0.1 lux, (**c**) 0.5 lux, (**d**) 1.0 lux and (**e**) 5.0 lux.
