Estimating Crop Albedo in the Application of a Physical Model Based on the Law of Energy Conservation and Spectral Invariants

Remote Sensing

Jingjing Peng²  Wenjie Fan²  Xiru Xu²  Lizhao Wang¹  Qinhuo Liu³  Jvcai Li²  Peng Zhao²  Xin Li⁴  Yuei-An Liou⁴  Richard Müller⁴ 

[1] Beijing Research Institute of Automation for Machinery Industry, Beijing 100120, China; E-Mail:;Institute of RS and GIS, Peking University, Beijing 100871, China; E-Mails:;State Key Laboratory of Remote Sensing Science, jointly sponsored by Institute of Remote Sensing and Digital Earth of CAS and Beijing Normal University, Beijing 100101, ChinaInstitute of RS and GIS, Peking University, Beijing 100871, China;

关键词: albedo;    crop;    spectral invariant;   

DOI  :  10.3390/rs71115536

来源: mdpi

【 摘 要 】

Albedo characterizes the radiometric interface of land surfaces, especially vegetation, and the atmosphere. Albedo is a critical input to many models, such as crop growth models, hydrological models and climate models. For the extensive attention to crop monitoring, a physical albedo model for crops is developed based on the law of energy conservation and spectral invariants, which is derived from a prior forest albedo model. The model inputs have been efficiently and physically parameterized, including the dependency of albedo on the solar zenith/azimuth angle, the fraction of diffuse skylight in the incident radiance, the canopy structure, the leaf reflectance/transmittance and the soil reflectance characteristics. Both the anisotropy of soil reflectance and the clumping effect of crop leaves at the canopy scale are considered, which contribute to the improvement of the model accuracy. The comparison between the model results and Monte Carlo simulation results indicates that the canopy albedo has high accuracy with an RMSE < 0.005. The validation using ground measurements has also demonstrated the reliability of the model and that it can reflect the interaction mechanism between radiation and the canopy-soil system.

【 授权许可】

CC BY   
© 2015 by the authors; licensee MDPI, Basel, Switzerland.