Validation of Biophysical Parameters of Wheat Retrieved from Sentinel-2 Data Using in-situ Measurements at Anand Region of India

Abstract

The purpose of this study was to evaluate the accuracy of the Sentinel-2 chlorophyll content and the Leaf Area Index (LAI) retrieved via SNAP toolbox using in situ observed biophysical parameters. SL2B plugins were tested for accuracy and consistency through validation and comparison of spatial variation. The SNAP processor showed good correlations for Leaf Area Index (LAI) in the first year, and it was particularly successful in some selected fields. For the various areas, satisfactory accuracy was maintained in the second year. The findings revealed a reasonable R2, ranging from 0.5 to 0.7, between in-situ LAI and SNAP-retrieved LAI, but with high errors. In chlorophyll assessment, the average estimates of SL2P-derived values were 20 – 90 µg/cm², against the mean values of 40–50 µg/cm² as observed in the field. The standard deviation for the chlorophyll generated from SL2P, albeit variable, was moderate (22.68 µg/cm²). The scatter plots highlighted a close agreement between retrieved and measured values, reinforcing the reliability of the data. Retrievals of LAI and chlorophyll were accurate for Anand district. It highlights the potential of Sentinel 2 data for reliable retrieval of biophysical parameters of wheat.