Thermal bidirectional gap probability model for row crop canopies and validation

Based on the row structure model of Kimes and the mean gap probability model in single direction, we develop a bidirectional gap probability model for row crop canopies. A concept of overlap index is introduced in this model to consider the gaps and their correlation between the sun and view directions. Multiangular thermal emission data sets were measured in Shunyi, Beijing, and these data are used in model validation in this paper. By comparison with the Kimes model that does not consider the gap probability, and the model considering the gap in view direction only, it is found that our bidirectional gap probability model fits the field measurements over winter wheat much better.

[1]  Alan H. Strahler,et al.  A conceptual model for effective directional emissivity from nonisothermal surfaces , 1999, IEEE Trans. Geosci. Remote. Sens..

[2]  D. S. Kimes,et al.  Remote sensing of row crop structure and component temperatures using directional radiometric temperatures and inversion techniques , 1983 .

[3]  Alan H. Strahler,et al.  Geometric-optical bidirectional reflectance modeling of the discrete crown vegetation canopy: effect of crown shape and mutual shadowing , 1992, IEEE Trans. Geosci. Remote. Sens..

[4]  Daniel S. Kimes,et al.  Directional radiometric measurements of row-crop temperatures , 1983 .

[5]  Wenjie Fan,et al.  A bi-directional gap model for simulating the directional thermal radiance of row crops , 2002 .

[6]  Alan H. Strahler,et al.  Study on thermal infrared emission directionality over crop canopies with TIR camera imagery , 2000 .

[7]  R. D. Jackson,et al.  View angle effects in the radiometric measurement of plant canopy temperatures , 1980 .

[8]  Alan H. Strahler,et al.  Modeling the gap probability of a discontinuous vegetation canopy , 1988 .

[9]  Jindi Wang,et al.  Component temperatures inversion for remote sensing pixel based on directional thermal radiation model , 2000 .

[10]  A. Strahler,et al.  Geometric-Optical Bidirectional Reflectance Modeling of a Conifer Forest Canopy , 1986, IEEE Transactions on Geoscience and Remote Sensing.

[11]  Jindi Wang,et al.  On utilization ofa priori knowledge in inversion of remote sensing models , 1998 .

[12]  Alan H. Strahler,et al.  Modeling bidirectional reflectance of forests and woodlands using boolean models and geometric optics , 1990 .

[13]  R D Jackson,et al.  Plant canopy information extraction from composite scene reflectance of row crops. , 1979, Applied optics.