Relationship between component brightness temperature and geo-structure of a maize canopy

Numerous researchers have observed that the distribution of brightness temperature field over an agricultural canopy strongly depended on canopy biophysical and phenological features coupling with environment conditions. Recently, an in situ experiment was conducted over a maize canopy in Avignon of France to investigate the temporal variation of brightness temperature distributions as a function of canopy geometrical structure. The experiment lasted 3 months throughout maize growth cycle. The results revealed that component brightness temperature (CBT) values are not independent with each other. The correlation of sunlit soil temperature minus vegetation temperature (T _sb-T_v) and shaded soil temperature minus vegetation temperature (T_so-T_v) is 0.85 with a RMSE of 1.1degC. In the analysis of maize geometrical structure when it was within its first two of three growth stages, good relations have been found between geometrical parameters with leaf area index LAI. To analyze the relation between CBT and LAI, the differences of CBTs were compared with LAI as a function of date of year, where we found that T _sb-T_so has the best relation with LAI. An initial interpretation was given to this result, which is still under further analysis based on more experiment observations. The tie between CBT and LAI is expected to be utilized in the researches on canopy energy balance estimation directly