Calibration of Brdf Effects in Paddy Field Reflectance from Temporal Modis Images

Moderate Resolution Imaging Spectroradiometer (MODIS) has a potential for more detailed daily monitoring of land covers and their change than ever because two bands, red and near-infrared bands, have 250m spatial resolutions. On the other hand, the use of MODIS data requires attention to Bidirectional Reflectance Distribution Function (BRDF) effect, which is one of the most important factors to calibrate reflectance obtained from remotely sensed data. In order to examine the possibility of BRDF estimation from MODIS data and BRDF calibration, firstly Bidirectional Reflectance Factor (BRF) data in paddy fields were measured on the ground during three months. Then, parameters of BRDF model were estimated using the ground data. Finally, parameters of BRDF model were estimated by using temporally successive sixteen -day MODIS images, and both BRDFs were compared. The experimental results reveal that while the ground BRDF and MODIS BRDF are similar, the degree of the BRDF curvature is different. Therefore, it is concluded that further research is required to apply the ground BRDF for the estimation of MODIS BRDF.