Estimation of Vegetation Canopy Water Content Using Hyperion Hyperspectral Data

Estimation of Vegetation Canopy Water Content Using Hyperion Hyperspectral Data

Spectroscopy and Spectral Analysis

Vegetation canopy water content (VCWC) has widespread utility in agriculture, ecology and hydrology. Based on the PROSAIL model, a novel model for quantitative inversion of vegetation canopy water content using Hyperion hyperspectral data was explored. Firstly, characteristics of vegetation canopy reflection were investigated with the PROSAIL radiative transfer model, and it was showed that the first derivative at the right slope (9801 070 nm) of the 970 nm water absorption feature (<i>D</i> _{9801 070}) was closely related to VCWC, and determination coefficient reached to 0.96. Then, bands 983, 993, 1 003, 1 013, 1 023, 1 033, 1 043, 1 053 and 1 063 nm of Hyperion data were selected to calculate <i>D</i> _{9801 070}, and VCWC was estimated using the proposed method. Finally, the retrieval result was verified using field measured data in Yingke oasis of the Heihe basin. It indicated that the mean relative error was 12.5%, RMSE was within 0.1 kg·m^-2 and the proposed model was practical and reliable. This study provides a more efficient way for obtaining VCWC of large area.