Toward the inversion of vegetation parameters using canopy reflectance models

In this study, we investigated the invertivility of vegetation parameters from reflectance spectra using Kuusk's canopy reflectance model. To acquire the bi-directional reflectance factors (BRFs) of the vegetative surface, we developed a multi input visible and near infrared spectrometer using a 2D CCD array as detector and four optical fibers as input probes. It can enable us to measure reference spectra and three target spectra simultaneously and it reduces the effect of the fluctuation of the direct solar and diffused sky radiation caused by moving clouds and changing solar direction. BRFs were acquired both in the field and In the laboratory to investigate the sensitivity of the vegetation parameters to canopy reflectance and compared with calculated ones. The sensitivity of the measured BRFs for each LAI was discussed with comparing in the visible and the near infrared BRFs data. And the possibility of the retrieval of LAI information from the hot spot effect was also discussed.